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Foo LL, Xu L, Sabanayagam C, Htoon HM, Ang M, Zhang J, Ohno-Matsui K, Cheng CY, Hoang QV, Tan CS, Saw SM, Wong CW. Predictors of myopic macular degeneration in a 12-year longitudinal study of Singapore adults with myopia. Br J Ophthalmol 2023; 107:1363-1368. [PMID: 35534177 DOI: 10.1136/bjophthalmol-2021-321046] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 04/24/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE To investigate the predictive factors for myopic macular degeneration (MMD) and progression in adults with myopia. METHODS We examined 828 Malay and Indian adults (1579 myopic eyes) with myopia (spherical equivalent (SE) ≤-0.5 dioptres) at baseline who participated in both baseline and 12-year follow-up visits of the Singapore Malay Eye Study and the Singapore Indian Eye Study. Eye examinations, including subjective refraction and axial length (AL) measurements, were performed. MMD was graded from fundus photographs following the Meta-Analysis for Pathologic Myopia classification. The predictive factors for MMD development and progression were assessed in adults without and with MMD at baseline, respectively as risk ratios (RR) using multivariable modified Poisson regression models. The receiver operating characteristic curve was used to visualise the performance of the predictive models for the development of MMD, with performance quantified by the area under the curve (AUC). RESULTS The 12-year cumulative MMD incidence was 10.3% (95% CI 8.9% to 12.0%) among 1504 myopic eyes without MMD at baseline. Tessellated fundus was a major predictor of MMD (RR=2.50, p<0.001), among other factors including age, worse SE and longer AL (all p<0.001). The AUC for prediction of MMD development was found to be 0.78 (95% CI 0.76 to 0.80) for tessellated fundus and increased significantly to an AUC of 0.86 (95% CI 0.84 to 0.88) with the combination of tessellated fundus with age, race, gender and SE (p<0.001). Older age (p=0.02), worse SE (p<0.001) and longer AL (p<0.001) were found to be predictors of MMD progression. CONCLUSIONS In adults with myopia without MMD, tessellated fundus, age, SE and AL had good predictive value for incident MMD. In adults with MMD, 1 in 10 eyes experienced progression over the same period. Older age, more severe myopia and longer AL were independent risk factors for progression.
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Affiliation(s)
- Li Lian Foo
- Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | | | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | | | - Marcus Ang
- Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Jingwen Zhang
- GKT School of Medicine, King's College London, London, UK
| | - Kyoko Ohno-Matsui
- Ophthalmology and Visual Science, Tokyo Medical and Dental University, Bunkyo-ku, Japan
| | - Ching Yu Cheng
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Quan V Hoang
- Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
- Dept. of Ophthalmology, Columbia University, New York, New York, USA
| | - Chuen-Seng Tan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Seang-Mei Saw
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Chee Wai Wong
- Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
- Asia Pacific Eye Centre, Gleneagles Hospital, Singapore
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Foo LL, Tan CS, Noel B, Htoon HM, Najjar RP, Kathrani B, Sabanayagam C, Saw SM. Factors influencing myopia stabilisation in young myopic adult Singaporeans. Br J Ophthalmol 2023:bjo-2023-323680. [PMID: 37640399 DOI: 10.1136/bjo-2023-323680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 07/23/2023] [Indexed: 08/31/2023]
Abstract
PURPOSE To evaluate factors influencing stabilisation of myopia in the Singapore Cohort of Risk factors for Myopia. METHODS We evaluated the longitudinal natural history of 424 myopic participants from 1999 to 2022. The outcome was the change in myopia from the adolescence follow-up visit (aged 12-19 years) to the adulthood follow-up visit (aged 26-33 years). Association of predictive factors, including baseline spherical error, gender, ethnicity, parental myopia, time outdoor, near work and age at adolescence, was examined with the dichotomous outcome of adult myopia progression (≤ -1.00 dioptres (D) over 10 years) using multiple logistic regression and progression in linear regression models. RESULTS For the primary outcome, the mean rate of progression of the outcome was found to be -0.04±0.09 D per year from the adolescent to the adulthood follow-up visits. 82.3% (95% CI 78.3% to 85.8%) had myopia stabilisation, with progression of less than 1.00 D over 10 years while 61.3% (95% CI 56.5% to 66.0%) of the subjects had progression of less than 0.50 D. In logistic regression models, both male gender (p=0.035) and non-Chinese ethnicity (p=0.032) were more likely to achieve myopia stabilisation while in linear multivariate regression models, males had a significantly slower degree of myopia progression (p=0.021). CONCLUSION 5 in 6 Singaporean young adults had myopia stabilisation. Male gender is 2 times and non-Chinese ethnicities are 2.5 times more likely to achieve myopia stabilisation. However, a proportion of myopes continue to exhibit a clinically significant degree of progression in adulthood.
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Affiliation(s)
- Li Lian Foo
- Singapore National Eye Centre, Singapore
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Chuen-Seng Tan
- National University Singapore Saw Swee Hock School of Public Health, Singapore
| | - Brennan Noel
- Johnson & Johnson Vision, Jacksonville, Florida, USA
| | | | - Raymond P Najjar
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Seang-Mei Saw
- Singapore Eye Research Institute, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore
- National University Singapore Saw Swee Hock School of Public Health, Singapore
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3
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Wong EN, Foo VHX, Peh GSL, Htoon HM, Ang HP, Tan BYL, Ong HS, Mehta JS. Early Visibility of Cellular Aggregates and Changes in Central Corneal Thickness as Predictors of Successful Corneal Endothelial Cell Injection Therapy. Cells 2023; 12:cells12081167. [PMID: 37190076 DOI: 10.3390/cells12081167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 05/17/2023] Open
Abstract
(1) Background: Cell injection therapy is an emerging treatment for bullous keratopathy (BK). Anterior segment optical coherence tomography (AS-OCT) imaging allows the high-resolution assessment of the anterior chamber. Our study aimed to investigate the predictive value of the visibility of cellular aggregates for corneal deturgescence in an animal model of bullous keratopathy. (2) Methods: Cell injections of corneal endothelial cells were performed in 45 eyes in a rabbit model of BK. AS-OCT imaging and central corneal thickness (CCT) measurement were performed at baseline and on day 1, day 4, day 7 and day 14 following cell injection. A logistic regression was modelled to predict successful corneal deturgescence and its failure with cell aggregate visibility and CCT. Receiver-operating characteristic (ROC) curves were plotted, and areas under the curve (AUC) calculated for each time point in these models. (3) Results: Cellular aggregates were identified on days 1, 4, 7 and 14 in 86.7%, 39.5%, 20.0% and 4.4% of eyes, respectively. The positive predictive value of cellular aggregate visibility for successful corneal deturgescence was 71.8%, 64.7%, 66.7% and 100.0% at each time point, respectively. Using logistic regression modelling, the visibility of cellular aggregates on day 1 appeared to increase the likelihood of successful corneal deturgescence, but this did not reach statistical significance. An increase in pachymetry, however, resulted in a small but statistically significant decreased likelihood of success, with an odds ratio of 0.996 for days 1 (95% CI 0.993-1.000), 2 (95% CI 0.993-0.999) and 14 (95% CI 0.994-0.998) and an odds ratio of 0.994 (95% CI 0.991-0.998) for day 7. The ROC curves were plotted, and the AUC values were 0.72 (95% CI 0.55-0.89), 0.80 (95% CI 0. 62-0.98), 0.86 (95% CI 0.71-1.00) and 0.90 (95% CI 0.80-0.99) for days 1, 4, 7 and 14, respectively. (4) Conclusions: Logistic regression modelling of cell aggregate visibility and CCT was predictive of successful corneal endothelial cell injection therapy.
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Affiliation(s)
- Evan N Wong
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 169856, Singapore
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, Perth, WA 6009, Australia
| | - Valencia H X Foo
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 169856, Singapore
| | - Gary S L Peh
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Department of Ophthalmology and Visual Science, Duke-National University of Singapore (NUS) Graduate Medical School, Singapore 169857, Singapore
| | - Hla M Htoon
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Department of Ophthalmology and Visual Science, Duke-National University of Singapore (NUS) Graduate Medical School, Singapore 169857, Singapore
| | - Heng-Pei Ang
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 169856, Singapore
| | - Belinda Y L Tan
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 169856, Singapore
| | - Hon-Shing Ong
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 169856, Singapore
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Department of Ophthalmology and Visual Science, Duke-National University of Singapore (NUS) Graduate Medical School, Singapore 169857, Singapore
| | - Jodhbir S Mehta
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 169856, Singapore
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Department of Ophthalmology and Visual Science, Duke-National University of Singapore (NUS) Graduate Medical School, Singapore 169857, Singapore
- School of Material Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
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Varela MMD, Bibay JIA, Ogden BE, Crim MJ, Htoon HM. Using Sterile Flocked Swabs as an Alternative Method for Rodent Health Monitoring. J Am Assoc Lab Anim Sci 2022; 61:370-380. [PMID: 35764385 PMCID: PMC9674010 DOI: 10.30802/aalas-jaalas-22-000024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/14/2022] [Accepted: 05/18/2022] [Indexed: 01/03/2023]
Abstract
Routine health monitoring is an integral part of managing SPF rodent colonies. In recent years, rack-level environmental sampling has been introduced as an adjunct method or replacement for exposure of sentinel rodents to soiled bedding. However, rack-level environmental monitoring is not compatible with rodent housing systems that have cage-level filtration. The current study investigated whether exposure of sterile flocked swabs to soiled bedding can be an alternative sampling method for routine health monitoring in mice, thus replacing the use of sentinels in soiled-bedding cages. Flocked swabs were placed in cages containing pooled samples of soiled bedding but no mice; swabs remained there for 90 d, with weekly agitation and biweekly swabbing of the cage floor to mimic the agitation of soiled bedding by sentinel mice and facilitate the collection of dust particles. Fecal samples were collected from both colony and sentinel mice. For environmental samples, exhaust debris was collected from the rack plenum, and dust samples were collected from the exhaust hose. All samples were collected on days 88 through 91 and were tested for multiple pathogens by using real-time PCR assays. To determine the diagnostic agreement of flocked swab sampling with the other methods, we used κ statistics to compare the test results from flocked swabs with those from sentinel feces, exhaust debris, and colony animal feces; we found excellent agreement between the colony feces and the flocked swab methods. The sterile flocked swab method detected all enzootic pathogens in the colonies tested. Results from flocked swab samples had the least agreement with sentinel feces, which also failed to detect the presence of fur mites. This study supports the use of sterile flocked swabs as alternative to using sentinel mice, thus conforming to the guiding principles of replacement and reduction in the use of animals for routine colony health monitoring.
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Affiliation(s)
- Mynn Michelle D Varela
- Duke-NUS Medical School, Singapore; SingHealth Experimental Medicine Centre, Singapore Health Services, Singapore;,
| | - Jan Irving A Bibay
- Biological Resource Centre, Agency for Science, Technology and Research, Singapore
| | - Bryan E Ogden
- Duke-NUS Medical School, Singapore; SingHealth Experimental Medicine Centre, Singapore Health Services, Singapore
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Ong HS, Htoon HM, Ang M, Mehta JS. “Endothelium-Out” and “Endothelium-In” Descemet Membrane Endothelial Keratoplasty (DMEK) Graft Insertion Techniques: A Systematic Review With Meta-Analysis. Front Med (Lausanne) 2022; 9:868533. [PMID: 35775001 PMCID: PMC9237218 DOI: 10.3389/fmed.2022.868533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/10/2022] [Indexed: 11/24/2022] Open
Abstract
Background We evaluated the visual outcomes and complications of “endothelium-out” and “endothelium-in” Descemet membrane endothelial keratoplasty (DMEK) graft insertion techniques. Materials and Methods Electronic searches were conducted in CENTRAL, Cochrane databases, PubMed, EMBASE, ClinicalTrials.gov. Study designs included clinical trials, comparative observational studies, and large case series (≥25 eyes). PRISMA guidelines were used for abstracting data and synthesis. Random-effects models were employed for meta-analyses. Results 21,323 eyes (95 studies) were included. Eighty-six studies reported on “endothelium-out” techniques; eight studies reported on “endothelium-in” techniques. One study compared “endothelium-out” to “endothelium-in” techniques. Eighteen “endothelium-out” studies reported that 42.5–85% of eyes achieved best-corrected visual acuity (BCVA) ≥20/25 at 6 months; pooled proportion of eyes achieving BCVA ≥20/25 at 6 months was 58.7% (95% CI 49.4–67.7%,15 studies). Three “endothelium-in” studies reported that 44.7–87.5% of eyes achieved BCVA of ≥20/25 at 6 months; pooled proportion of eyes achieving BCVA ≥20/25 at 6 months was 62.4% (95% CI 33.9–86.9%). Pooled mean endothelial cell loss was lower in the “endothelium-in” studies (28.1 ± 1.3%, 7 studies) compared to “endothelium-out” studies (36.3 ± 6.9%,10 studies) at 6 months (p = 0.018). Graft re-bubbling rates were higher in the “endothelium-out” studies (26.2%, 95% CI 21.9–30.9%, 74 studies) compared to “endothelium-in” studies (16.5%, 95% CI 8.5–26.4%, 6 studies), although statistical significance was not reached (p = 0.440). Primary graft failure rates were comparable between the two groups (p = 0.552). Quality of evidence was considered low and significant heterogeneity existed amongst the studies. Conclusion Reported rates of endothelial cell loss were lower in “endothelium-in” DMEK studies at 6 months compared to “endothelium-out” studies. Outcomes of “endothelium-in” techniques were otherwise comparable to those reported in “endothelium-out” studies. Given the technical challenges encountered in “endothelium-out” procedures, surgeons may consider “endothelium-in” techniques designed for easier intra-operative DMEK graft unfolding. “Endothelium-in” studies evaluating outcomes at longer time points are required before conclusive comparisons between the two techniques can be drawn.
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Affiliation(s)
- Hon Shing Ong
- Department of Corneal & External Eye Diseases, Singapore National Eye Centre, Singapore, Singapore
- Singapore Eye Research Institute, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
- Hon Shing Ong,
| | - Hla M. Htoon
- Singapore Eye Research Institute, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
| | - Marcus Ang
- Department of Corneal & External Eye Diseases, Singapore National Eye Centre, Singapore, Singapore
- Singapore Eye Research Institute, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
| | - Jodhbir S. Mehta
- Department of Corneal & External Eye Diseases, Singapore National Eye Centre, Singapore, Singapore
- Singapore Eye Research Institute, Singapore, Singapore
- Duke-NUS Medical School, Singapore, Singapore
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore
- *Correspondence: Jodhbir S. Mehta,
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Ting DSJ, Goh ETL, Mayandi V, Busoy JMF, Aung TT, Periayah MH, Nubile M, Mastropasqua L, Said DG, Htoon HM, Barathi VA, Beuerman RW, Lakshminarayanan R, Mohammed I, Dua HS. Hybrid derivative of cathelicidin and human beta defensin-2 against Gram-positive bacteria: A novel approach for the treatment of bacterial keratitis. Sci Rep 2021; 11:18304. [PMID: 34526600 PMCID: PMC8443647 DOI: 10.1038/s41598-021-97821-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/24/2021] [Indexed: 02/06/2023] Open
Abstract
Bacterial keratitis (BK) is a major cause of corneal blindness globally. This study aimed to develop a novel class of antimicrobial therapy, based on human-derived hybrid host defense peptides (HyHDPs), for treating BK. HyHDPs were rationally designed through combination of functional amino acids in parent HDPs, including LL-37 and human beta-defensin (HBD)-1 to -3. Minimal inhibitory concentrations (MICs) and time-kill kinetics assay were performed to determine the concentration- and time-dependent antimicrobial activity and cytotoxicity was evaluated against human corneal epithelial cells and erythrocytes. In vivo safety and efficacy of the most promising peptide was examined in the corneal wound healing and Staphylococcus aureus (ATCC SA29213) keratitis murine models, respectively. A second-generation HyHDP (CaD23), based on rational hybridization of the middle residues of LL-37 and C-terminal of HBD-2, was developed and was shown to demonstrate good efficacy against methicillin-sensitive and methicillin-resistant S. aureus [MIC = 12.5-25.0 μg/ml (5.2-10.4 μM)] and S. epidermidis [MIC = 12.5 μg/ml (5.2 μM)], and moderate efficacy against P. aeruginosa [MIC = 25-50 μg/ml (10.4-20.8 μM)]. CaD23 (at 25 μg/ml or 2× MIC) killed all the bacteria within 30 min, which was 8 times faster than amikacin (25 μg/ml or 20× MIC). After 10 consecutive passages, S. aureus (ATCC SA29213) did not develop any antimicrobial resistance (AMR) against CaD23 whereas it developed significant AMR (i.e. a 32-fold increase in MIC) against amikacin, a commonly used treatment for BK. Pre-clinical murine studies showed that CaD23 (0.5 mg/ml) achieved a median reduction of S. aureus bioburden by 94% (or 1.2 log10 CFU/ml) while not impeding corneal epithelial wound healing. In conclusion, rational hybridization of human-derived HDPs has led to generation of a potentially efficacious and safe topical antimicrobial agent for treating Gram-positive BK, with no/minimal risk of developing AMR.
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Affiliation(s)
- Darren Shu Jeng Ting
- Academic Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
- Department of Ophthalmology, Queen's Medical Centre, Nottingham, UK
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Eunice Tze Leng Goh
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Venkatesh Mayandi
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Joanna M F Busoy
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | - Thet Tun Aung
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | | | - Mario Nubile
- Ophthalmic Clinic, University "G d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | | | - Dalia G Said
- Academic Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
- Department of Ophthalmology, Queen's Medical Centre, Nottingham, UK
| | - Hla M Htoon
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore, Singapore
| | | | - Roger W Beuerman
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore, Singapore
- Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, USA
| | | | - Imran Mohammed
- Academic Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK
| | - Harminder S Dua
- Academic Ophthalmology, Division of Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK.
- Department of Ophthalmology, Queen's Medical Centre, Nottingham, UK.
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7
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Fenwick EK, Ozdemir S, Man REK, Baid D, Htoon HM, Gan ATL, Tey ML, Aw AT, Baskaran M, Nongpiur ME, Finkelstein EA, Tey CS, Soon HJT, Sabanayagam C, Sng CCA, Wong TY, Husain R, Perera SA, Lun K, Aung T, Lamoureux EL. Development and Validation of a Preference-Based Glaucoma Utility Instrument Using Discrete Choice Experiment. JAMA Ophthalmol 2021; 139:866-874. [PMID: 34165504 DOI: 10.1001/jamaophthalmol.2021.1874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Importance A glaucoma-specific instrument for estimating utilities across the spectrum of glaucoma severity is currently lacking, hindering the assessment of the cost-effectiveness of glaucoma treatments. Objective To develop and validate the preference-based Glaucoma Utility Instrument (Glau-U) and to ascertain the association between Glau-U utilities and severity of glaucoma and vision impairment. Design, Setting, and Participants This cross-sectional study was conducted in 2 stages at the Singapore National Eye Centre glaucoma clinics. Stage 1 focused on the identification and pretesting of the Glau-U attributes and was carried out between June 2009 and May 2016. Stage 2 involved the development and administration of the discrete choice experiment (DCE) survey and tasks and was conducted between May 7, 2018, and December 11, 2019. Stage 2 participants were English- or Mandarin-speaking Singaporean citizens or permanent residents of Chinese, Malay, or Indian ethnicity who were 40 years or older and had a clinical diagnosis of glaucoma in at least 1 eye. Exposures Glau-U comprised 6 quality-of-life attributes: activities of daily living, lighting and glare, movement, eye discomfort, other effects of glaucoma, and social and emotional effects. The descriptions or response options for these attributes were no difficulty or never, some difficulty or sometimes, or severe difficulty or often. Main Outcomes and Measures Utility weights for Glau-U were developed using a DCE questionnaire, which was interviewer administered to participants. Mixed logit regression determined utility weights for each health state. Glau-U utility weights across better- or worse-eye glaucoma and vision impairment severity were calculated using 1-way analysis of variance. Correlations between Glau-U utilities and better- or worse-eye visual fields and EuroQol 5-Dimension utilities were ascertained to assess convergent and divergent validity. Results Of the 304 participants (mean [SD] age, 68.3 [8.7] years; 182 men [59.9%]), 281 (92.4%) had no vision impairment in the better eye, 13 (4.3%) had mild impairment, and 10 (3.3%) had moderate to severe vision impairment. Mean (SD) Glau-U utilities decreased as better-eye glaucoma severity increased (none: 0.73 [0.21]; mild: 0.66 [0.21]; moderate: 0.66 [0.20]; severe: 0.60 [0.28]; and advanced or end-stage: 0.22 [0.38]; P < .001), representing reductions of 20.7% to 76.1% in quality-adjusted life-years compared with a health state that included preperimetric glaucoma. Mean (SD) Glau-U utilities also decreased as better-eye vision impairment worsened from 0.67 (0.23) for none to 0.58 (0.32) for mild to 0.46 (0.29) for moderate to severe vision impairment. Glau-U utilities demonstrated moderate correlations with better-eye (r = 0.34; P < .001) and worse-eye (r = 0.33; P < .001) mean deviation scores and low correlations with EuroQol 5-Dimension utilities (r = 0.22; P < .001), supporting convergent and divergent validity. Conclusions and Relevance Use of Glau-U revealed large decrements in utility that were associated with late-stage glaucoma, suggesting that this new instrument may be useful for cost-effectiveness analyses of interventions and informing resource allocation policies for glaucoma and vision loss.
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Affiliation(s)
- Eva K Fenwick
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, National University of Singapore, Singapore
| | - Semra Ozdemir
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Ryan E K Man
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, National University of Singapore, Singapore
| | - Drishti Baid
- Duke-NUS Medical School, National University of Singapore, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, National University of Singapore, Singapore
| | - Alfred T L Gan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Min Li Tey
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ai T Aw
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Mani Baskaran
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | | | - Ching Siong Tey
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Emory University, School of Medicine, Atlanta, Georgia
| | - Hasita J T Soon
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, National University of Singapore, Singapore
| | - Chelvin C A Sng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,National University Health System, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Rahat Husain
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Shamira A Perera
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | | | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, National University of Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ecosse L Lamoureux
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, National University of Singapore, Singapore
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8
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Lanca C, Sun CH, Chong R, Wong YL, Nongpiur ME, Htoon HM, Thakur S, Quek DQY, Cheng CY, Hoang QV, Sabanayagam C, Saw SM, Wong CW. Visual field defects and myopic macular degeneration in Singapore adults with high myopia. Br J Ophthalmol 2021; 106:1423-1428. [PMID: 33888462 DOI: 10.1136/bjophthalmol-2020-318674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/05/2021] [Accepted: 04/10/2021] [Indexed: 11/03/2022]
Abstract
AIMS To characterise the association between visual field (VF) defects and myopic macular degeneration (MMD) in highly myopic adults without glaucoma. METHODS Participants (n=106; 181 eyes) with high myopia (HM; spherical equivalent ≤-5.0 D or axial length (AL) ≥26 mm), after excluding glaucoma and glaucoma suspects, from the Singapore Epidemiology of Eye Diseases-HM study were included in this cross-sectional study. Humphrey VF (central 24-2 threshold), cup-disc ratio (CDR) and intraocular pressure (IOP) measurements were performed. Mean deviation (MD) and pattern SD (PSD), VF defects (normal or abnormal; p<0.05 in ≥3 non-edge contiguous locations) and pattern (eg, generalised sensitivity loss) were analysed. MMD presence was diagnosed from fundus photographs. Generalised estimating equations were used for analysing factors (MD, PSD, VF defects, CDR and IOP) associated with MMD. RESULTS Mean age was 55.4±9.9 years and 51.9% were women (AL=26.7±1.1 mm). MMD eyes had lower MD (-3.8±2.9 dB vs -1.1±1.4 dB) and higher PSD (2.8±1.7 dB vs 1.7±0.6 dB). A higher percentage of MMD eyes (n=48) had abnormal VF (62.5% vs 28.6%; p<0.001) compared with no MMD (n=133 eyes). VF pattern in MMD eyes was significantly different from eyes without MMD (p=0.001) with greater generalised sensitivity loss (53.3% vs 10.5%) and arcuate defects (16.7% vs 10.5%). In multivariate analyses, MD (OR=1.52) and PSD (OR=1.67) were significantly (p=0.003) associated with MMD, but VF defects were not associated with MMD. CONCLUSION Highly myopic adults with MMD may have VF loss when compared with highly myopic patients without MMD even in adults without glaucoma.
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Affiliation(s)
| | - Chen Hsin Sun
- Department of Ophthalmology, National University Hospital, Singapore
| | - Rachel Chong
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Yee Ling Wong
- R&D Vision Sciences AMERA, Essilor International, Singapore
| | - Monisha Esther Nongpiur
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore
| | - Sahil Thakur
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore
| | - Debra Q Y Quek
- Duke-NUS Medical School, Singapore.,Ministry of Health Holdings Pte Ltd, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Quan V Hoang
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Charumathi Sabanayagam
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore
| | - Seang-Mei Saw
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | - Chee Wai Wong
- Singapore Eye Research Institute, Singapore .,Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore
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9
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Wang X, Tun TA, Nongpiur ME, Htoon HM, Tham YC, Strouthidis NG, Aung T, Cheng CY, Girard MJ. Peripapillary sclera exhibits a v-shaped configuration that is more pronounced in glaucoma eyes. Br J Ophthalmol 2020; 106:491-496. [PMID: 33334817 DOI: 10.1136/bjophthalmol-2020-317900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/02/2020] [Accepted: 11/19/2020] [Indexed: 12/16/2022]
Abstract
AIMS To compare the shape of the anterior surface of the peripapillary sclera (PPS) between glaucoma and healthy subjects. METHODS 88 primary open angle glaucoma (POAG), 98 primary angle closure glaucoma (PACG) and 372 age-matched and gender-matched healthy controls were recruited in this study. The optic nerve head of one randomly selected eye of each subject was imaged with spectral domain optical coherence tomography. The shape of the PPS was measured through an angle defined between a line parallel to the nasal anterior PPS boundary and one parallel to the temporal side. A negative value indicated that the PPS followed an inverted v-shaped configuration (peak pointing towards the vitreous), whereas a positive value indicated that it followed a v-shaped configuration. RESULTS The mean PPS angle in normal controls (4.56±5.99°) was significantly smaller than that in POAG (6.60±6.37°, p=0.011) and PACG (7.90±6.87°, p<0.001). The v-shaped PPS was significantly associated with older age (β=1.79, p<0.001), poorer best-corrected visual acuity (β=3.31, p=0.047), central corneal thickness (β=-0.28, p=0.001), peripapillary choroidal thickness (β=-0.21, p<0.001) and presence of POAG (β=1.94, p<0.009) and PACG (β=2.96, p<0.001). The v-shaped configuration of the PPS significantly increased by 1.46° (p=0.001) in healthy controls for every 10-year increase in age, but not in glaucoma groups. CONCLUSIONS The v-shaped configuration of the PPS was more pronounced in glaucoma eyes than in healthy eyes. This posterior bowing of the PPS may have an impact on the biomechanical environment of the optic nerve head.
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Affiliation(s)
- Xiaofei Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Tin A Tun
- Ophthalmic Engineering & Innovation Laboratory, Singapore Eye Research Institute, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Monisha Esther Nongpiur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Yih Chung Tham
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Nicholas G Strouthidis
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Discipline of Clinical Ophthalmology and Eye Health, University of Sydney, Sydney, New South Wales, Australia
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore.,Duke-NUS Medical School, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Michael Ja Girard
- Ophthalmic Engineering & Innovation Laboratory, Singapore Eye Research Institute, Singapore .,Duke-NUS Medical School, Singapore
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10
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Ting DSJ, Chua D, May KO, Aung M, Kumar A, Farook M, Htoon HM, C A Sng C, Ang M. Modified manual small incision cataract surgery technique for phacoemulsification-trained surgeons. Ther Adv Ophthalmol 2020; 12:2515841420977372. [PMID: 33344883 PMCID: PMC7727050 DOI: 10.1177/2515841420977372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/23/2020] [Indexed: 01/09/2023] Open
Abstract
Purpose: To present the technique and outcomes of a modified manual small incision cataract surgery designed for the phacoemulsification surgeons who are learning to perform manual small incision cataract surgery. Methods: This was a retrospective, single-centred, comparative study. We included all the patients who underwent the modified manual small incision cataract surgery for visually significant cataract at Singapore National Eye Centre. All surgeries were performed by either a senior phaco-trained surgeon (M.A.) who had performed more than 500 manual small incision cataract surgery or a junior phaco-trained surgeon (D.C.) who had performed around 500 phacoemulsification but never performed any manual small incision cataract surgery. The main modification of this technique lies in the creation of an additional phaco-like main wound at 90° to the scleral tunnel wound, with most surgical steps performed through this additional wound. The outcomes were analysed and compared between the senior and junior surgeons. The main outcome measures were visual outcome and major intraoperative complications such as posterior capsular rupture and zonular dialysis. Results: A total of 132 cases were included; 102 (77.3%) and 30 (22.7%) cases were performed by the senior and junior surgeons, respectively. Pre-operatively, 85.6% eyes had best-corrected visual acuity of counting fingers or worse. Postoperatively, the visual outcome at 1 month was similar between the senior and junior surgeons, with 68.7% eyes achieving a best-corrected visual acuity of ⩾6/12 (p = 0.17). No posterior capsular rupture, zonular dialysis or endophthalmitis was observed during the study period. Conclusions: This modified technique may serve as a useful transition technique for the phaco-trained surgeons to develop skills in manual small incision cataract surgery, with demonstrable good visual outcome and safety.
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Affiliation(s)
- Darren S J Ting
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, UK
| | | | - Khin Oo May
- Sitagu International Missionary Association, Yangon, UK
| | - Mya Aung
- Sitagu International Missionary Association, Yangon, UK
| | | | | | - Hla M Htoon
- Singapore Eye Research Institute, Singapore; Ophthalmology and Visual Sciences, Duke - NUS Graduate Medical School, Singapore
| | - Chelvin C A Sng
- Singapore Eye Research Institute, Singapore; Department of Ophthalmology, National University Hospital, Singapore
| | - Marcus Ang
- Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751
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11
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Woo JH, Arundhati A, Chee SP, Tong W, Li L, Ti SE, Htoon HM, Choo JQH, Tan D, Mehta JS. Endothelial keratoplasty with anterior chamber intraocular lens versus secondary posterior chamber intraocular lens. Br J Ophthalmol 2020; 106:203-210. [PMID: 33115769 DOI: 10.1136/bjophthalmol-2020-316711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/19/2020] [Accepted: 10/06/2020] [Indexed: 11/04/2022]
Abstract
AIM To describe the long-term outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) with an anterior chamber intraocular lens (ACIOL) compared to secondary posterior chamber (PC) IOL. METHODS This was a retrospective comparative cohort study. The clinical data of 82 eyes from 82 consecutive patients with pseudophakic (PBK) or aphakic bullous keratopathy (ABK) who either underwent DSAEK with retained or secondary ACIOL (n=23) or DSAEK with IOL exchange and/or secondary PCIOL (retropupillary iris-claw IOL, n=25; intrascleral-fixated IOL, n=29; or sulcus IOL, n=5) were analysed. The main outcome measures were graft survival and complications up to 5 years. RESULTS The graft survival in the secondary PCIOL group was superior than the ACIOL group over 5 years (year 1, 100.0% vs 100.0%; year 3, 94.7% vs 75.0%; year 5, 91.1% vs 60.6%, p=0.022). The presence of an ACIOL was a significant risk factor associated with graft failure (HR, 4.801; 95% CI, 1.406 to 16.396, p=0.012) compared to a secondary PCIOL. There was no significant difference in the rate of graft detachment and elevated intraocular pressure between the groups. There were five cases (9.3%) of IOL subluxation or dislocation in the retropupillary iris-claw and intrascleral-fixated IOL groups. CONCLUSIONS Eyes that underwent DSAEK with ACIOL in situ had poorer long-term graft survival compared with those with secondary PCIOL. Intraocular lens exchange was not associated with a higher complication rate. In ABK or PBK eyes with ACIOL, we recommend performing IOL exchange and/or secondary PCIOL implantation combined with endothelial keratoplasty.
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Affiliation(s)
- Jyh Haur Woo
- Singapore National Eye Centre, Singapore .,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
| | - Anshu Arundhati
- Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
| | - Soon-Phaik Chee
- Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
| | | | - Lim Li
- Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
| | - Seng-Ei Ti
- Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
| | - Hla M Htoon
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
| | | | - Donald Tan
- Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore Eye Research Institute, Singapore
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12
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Ting DSJ, Liu YC, Patil M, Ji AJS, Fang XL, Tham YC, Lee YF, Htoon HM, Mehta JS. Proposal and validation of a new grading system for pterygium (SLIT2). Br J Ophthalmol 2020; 105:921-924. [PMID: 32788329 DOI: 10.1136/bjophthalmol-2020-315831] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 05/06/2020] [Accepted: 07/11/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND/AIMS To propose and validate a new pterygium grading system based on slit-lamp evaluation. METHODS This prospective cross-sectional study included 217 patients with pterygium. All patients underwent slit-lamp examination, and slit-lamp photographs were independently graded by two graders twice. A total of eight parameters were evaluated and all parameters were assigned with a score of 1-4 (normal-severe). Intra-rater and inter-rater reliability as determined by weighted Cohen's kappa analysis. RESULTS A total of 868 independent assessment, based on 217 slit-lamp images, were performed by two graders. For conjunctival assessment, the intra-rater reliability was excellent for body thickness (κ=0.81-0.89) and size at limbus (κ=0.87-0.92), substantial-to-excellent for body vascularity (κ=0.72-0.86), and moderate-to-excellent for body length (κ=0.57-0.81), whereas the inter-rater reliability was excellent for size at limbus (κ=0.86), substantial for body thickness (κ=0.72-0.73) and body vascularity (κ=0.66-0.75), and moderate for body length (κ=0.54-0.57). For corneal assessment, the intra-rater reliability was excellent for all four parameters (κ=0.84-0.90) whereas the inter-rater reliability was excellent for head length (κ=0.86-0.87), substantial-to-excellent for head vascularity (κ=0.78-0.82), substantial for Stocker's line (κ=0.79-0.80) and head thickness (κ=0.67-0.69). The grading system was named SLIT2, which included S tocker's line, S ize at limbus, L ength of head/body, I njection/vascularity of body/head, and T hickness of body/head. CONCLUSION The proposed SLIT2 grading system, consisting of eight components, may serve as a reliable tool to standardise the reporting of pterygium severity and disease recurrence for clinical and research applications.
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Affiliation(s)
- Darren Shu Jeng Ting
- Academic Ophthalmology, University of Nottingham, Nottingham, UK.,Singapore Eye Research Institute, Singapore, Singapore
| | - Yu-Chi Liu
- Singapore Eye Research Institute, Singapore, Singapore.,Cornea And Ext Disease, Singapore National Eye Centre, Singapore, Singapore
| | - Moushmi Patil
- Singapore Eye Research Institute, Singapore, Singapore
| | | | - Xiao Ling Fang
- Singapore Eye Research Institute, Singapore, Singapore.,Department of Ophthalmology, Shanghai Eye Diseases Prevention and Treatment Center, Shanghai, China
| | | | - Yi-Fang Lee
- Ophthalmology, Singapore National Eye Centre, Singapore, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore Eye Research Institute, Singapore, Singapore .,Cornea And Ext Disease, Singapore National Eye Centre, Singapore, Singapore
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13
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Ang M, Farook M, Htoon HM, Mehta JS. Reply. Ophthalmology 2020; 127:e100. [PMID: 32739178 DOI: 10.1016/j.ophtha.2020.06.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/13/2020] [Accepted: 06/18/2020] [Indexed: 11/30/2022] Open
Affiliation(s)
- Marcus Ang
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, The Academia, Singapore.
| | - Mohamed Farook
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, The Academia, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, The Academia, Singapore; Department of Ophthalmology and Visual Science, Duke-NUS Graduate Medical School, Singapore
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, The Academia, Singapore; Department of Ophthalmology and Visual Science, Duke-NUS Graduate Medical School, Singapore
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14
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Ang M, Farook M, Htoon HM, Mehta JS. Randomized Clinical Trial Comparing Femtosecond LASIK and Small-Incision Lenticule Extraction. Ophthalmology 2020; 127:724-730. [DOI: 10.1016/j.ophtha.2019.09.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/02/2019] [Accepted: 09/04/2019] [Indexed: 10/26/2022] Open
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15
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Ang BCH, Seen S, Kumaran A, De Leon JMS, Seah SKL, Foster PJ, Gazzard G, Htoon HM, Khaw PT, Aung T, Husain R. Visual field progression 8 years after trabeculectomy in Asian eyes: results from The Singapore 5-Fluorouracil Study. Br J Ophthalmol 2020; 104:1690-1696. [PMID: 32139502 DOI: 10.1136/bjophthalmol-2019-314121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 01/14/2020] [Accepted: 02/12/2020] [Indexed: 11/03/2022]
Abstract
BACKGROUND/AIMS This work aimed to study the effect of long-term intraocular pressure (IOP) fluctuation on visual field (VF) progression 8 years post-trabeculectomy in Asian eyes. METHODS This was a retrospective analysis of 8-year post-trabeculectomy data from The Singapore 5-Fluorouracil (5-FU) Study. VFs were analysed using Progressor software (Medisoft, Leeds, UK). Outcome measures included mean slope for VF per year, number of progressing points and mean slope for progressing points per year. Multivariate regression analyses were performed adjusting for age, gender, ethnicity, glaucoma type, intraoperative 5-FU, diabetes mellitus, hypertension, best pre-trabeculectomy VF mean deviation, post-trabeculectomy mean IOP, IOP reduction and IOP fluctuation (SD of IOPs at 6-monthly timepoints). RESULTS 127 (52.3%) subjects completed 8-year follow-up with ≥5 reliable VFs and ≥8 6-monthly IOP measurements. Mean age was 61.8±9.6 years. Post-operatively, mean IOP was 14.2±2.8 mm Hg and mean IOP fluctuation was 2.53±1.20 mm Hg. Higher IOP fluctuation was associated with greater mean slope for field (B=-0.071; p=0.013), number of progressing points (B=0.963; p=0.014) and VF progression as defined by ≥1 progressing point (OR=1.585; p=0.029). There was also a trend towards eyes with higher IOP fluctuation having ≥3 adjacent progressing points in the same hemifield (OR=1.489; p=0.055). Greater mean IOP reduction post-trabeculectomy was associated only with a lower mean slope for progressing points per year (B=-0.026; p=0.028). There was no significant effect of intra-operative 5-FU compared with placebo for all outcome measures. CONCLUSION In post-trabeculectomy Asian eyes with well-controlled IOP, higher long-term IOP fluctuation may be associated with greater VF progression.
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Affiliation(s)
- Bryan C H Ang
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore .,Singapore National Eye Centre, Singapore
| | - Sophia Seen
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | | | - John Mark Sim De Leon
- Singapore National Eye Centre, Singapore.,East Avenue Medical Center, Quezon City, Philippines
| | | | - Paul J Foster
- Division of Epidemiology, Institute of Ophthalmology, London, UK
| | - Gus Gazzard
- Glaucoma, NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | | | - Peng Tee Khaw
- Glaucoma, NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - Tin Aung
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore
| | - Rahat Husain
- Singapore National Eye Centre, Singapore.,Singapore Eye Research Institute, Singapore
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16
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Devarajan K, Sim R, Chua J, Wong CW, Matsumura S, Htoon HM, Schmetterer L, Saw SM, Ang M. Optical coherence tomography angiography for the assessment of choroidal vasculature in high myopia. Br J Ophthalmol 2019; 104:917-923. [PMID: 31585963 DOI: 10.1136/bjophthalmol-2019-314769] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/20/2019] [Accepted: 09/23/2019] [Indexed: 12/30/2022]
Abstract
AIMS To assess specific layers of the choroid in highly myopic young adults and to examine their associations with levels of myopia. METHODS We recruited 51 young myopes (n=91 eyes) from the Singapore Cohort of Risk Factors for Myopia cohort. We performed standardised optical coherence tomography (OCT) and OCT angiography imaging and developed a novel segmentation technique assessing choroidal layers' thickness (overall choroidal thickness (CT), medium-vessel choroidal layer (MVCL) thickness, large-vessel choroidal layer (LVCL)) and vasculature (choroidal vessel density (%), choroidal branch area (CBA, %) and mean choroidal vessel width (MCVW, mm)). RESULTS We found that eyes with extreme myopia (EM) had thinner vascular layers compared with high myopia (HM), that is, LVCL (36.0±1.5 vs 39.2±1.2 µm, p=0.002) and MVCL (185.5±5.7 vs 198.2±4.6 µm, p=0.014). Overall CT was thinnest in the nasal and inferior quadrants in EM (nasal: 157.1±9.6 vs 187.2±8.3 µm, p<0.001; superior: 236.6±11.1 vs 257.0±9.5 µm, p=0.02; temporal: 228.0±10.6 vs 254.3±8.8 µm, p=0.012; and inferior quadrant: 198.7±10.0 vs 239.8±8.3 µm, p=<0.001) when compared with HM. We also observed significantly more vessel branching in eyes with EM as compared with eyes with HM (CBA, 10.2%±0.7% vs 9.95%±0.8%, p=0.018). CONCLUSIONS The novel segmentation technique and introduced choroidal parameters may serve as new biomarkers to study disease conditions in myopia.
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Affiliation(s)
| | - Ralene Sim
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jacqueline Chua
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore, Singapore
| | - Chee Wai Wong
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore, Singapore
| | | | - Hla M Htoon
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore, Singapore
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore, Singapore.,Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,Nanyang Technological University, Singapore.,Saw Swee Hock School of Public Health, NUS, Singapore
| | - Seang Mei Saw
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore, Singapore.,Saw Swee Hock School of Public Health, NUS, Singapore
| | - Marcus Ang
- Singapore Eye Research Institute, Singapore .,Department of Ophthalmology and Visual Sciences, Duke-National University of Singapore, Singapore
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17
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Tun TA, Atalay E, Baskaran M, Nongpiur ME, Htoon HM, Goh D, Cheng CY, Perera SA, Aung T, Strouthidis NG, Girard MJA. Association of Functional Loss With the Biomechanical Response of the Optic Nerve Head to Acute Transient Intraocular Pressure Elevations. JAMA Ophthalmol 2019; 136:184-192. [PMID: 29302683 DOI: 10.1001/jamaophthalmol.2017.6111] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance The acute biomechanical response of the optic nerve head (ONH) to intraocular pressure (IOP) elevations may serve as a biomarker for the development and progression of glaucoma. Objective To evaluate the association between visual field loss and the biomechanical response of the ONH to acute transient IOP elevations. Design, Setting, and Participants In this observational study, 91 Chinese patients (23 with primary open-angle glaucoma [POAG], 45 with primary angle-closure glaucoma, and 23 without glaucoma) were recruited from September 3, 2014, through February 2, 2017. Optical coherence tomography scans of the ONH were acquired at baseline and at 2 sequential IOP elevations (0.64 N and then 0.90 N, by applying forces to the anterior sclera using an ophthalmodynamometer). In each optical coherence tomography volume, lamina cribrosa depth (LCD) and minimum rim width (MRW) were calculated. The mean deviation (MD) and the visual field index (VFI), as assessed by automated perimetry, were correlated with IOP-induced changes of LCD and MRW globally and sectorially. Main Outcomes and Measures The LCD, MRW, MD, and VFI. Results Among the 91 patients, 39 (42.9%) were women; the mean (SD) age was 65.48 (7.23) years. In POAG eyes, a greater change in LCD (anterior displacement) was associated with worse MD and VFI (R = -0.64; 95% CI, -0.97 to -0.31; P = .001; and R = -0.57; 95% CI, -0.94 to -0.19; P = .005, respectively) at the first IOP elevation, and a greater reduction in MRW was also associated with worse MD and VFI (first IOP elevation: R = -0.48; 95% CI, -0.86 to -0.09; P = .02; and R = -0.57; 95% CI, -0.94 to -0.20; P = .004, respectively; second IOP elevation: R = -0.56; 95% CI, -0.98 to -0.13; P = .01; and R = -0.60; 95% CI, -1.03 to -0.17; P = .008, respectively), after adjusting for age, sex, and baseline IOP. A correlation was found between the reduction in MRW in the inferior-temporal sector and the corresponding visual field cluster in POAG eyes at the second elevation (ρ = -0.55; 95% CI, -0.78 to -0.18; P = .006). Conclusions and Relevance The biomechanical response of the ONH to acute IOP elevations was associated with established visual field loss in POAG eyes, but not in primary angle-closure glaucoma eyes. This suggests that ONH biomechanics may be related to glaucoma severity in POAG and that the 2 glaucoma subgroups exhibit inherently different biomechanical properties.
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Affiliation(s)
- Tin A Tun
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Ophthalmic Engineering and Innovation Laboratory, Department of Biomedical Engineering, National University of Singapore, Singapore
| | - Eray Atalay
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Eskisehir Osmangazi University Faculty of Medicine, Eskisehir, Turkey
| | - Mani Baskaran
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Duke-National University of Singapore Medical School, Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Duke-National University of Singapore Medical School, Singapore
| | - David Goh
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Duke-National University of Singapore Medical School, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Shamira A Perera
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Duke-National University of Singapore Medical School, Singapore
| | - Tin Aung
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Duke-National University of Singapore Medical School, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Nicholas G Strouthidis
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Discipline of Clinical Ophthalmology and Eye Health, University of Sydney, Sydney, Australia.,National Institute for Health Research Biomedical Research Centre, Moorfields Eye Hospital National Health Service Foundation Trust and University College London Institute of Ophthalmology, London, United Kingdom
| | - Michaël J A Girard
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore.,Ophthalmic Engineering and Innovation Laboratory, Department of Biomedical Engineering, National University of Singapore, Singapore
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Lanca C, Teo A, Vivagandan A, Htoon HM, Najjar RP, Spiegel DP, Pu SH, Saw SM. The Effects of Different Outdoor Environments, Sunglasses and Hats on Light Levels: Implications for Myopia Prevention. Transl Vis Sci Technol 2019; 8:7. [PMID: 31360613 DOI: 10.1167/tvst.8.4.7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/27/2019] [Indexed: 02/05/2023] Open
Abstract
Purpose Lack of outdoor time is a known risk factor for myopia. Knowledge of the light levels reaching the eye and exposure settings, including sun-protective measures, is essential for outdoor programs and myopia. We evaluated the impact of sun-protective strategies (hat and sunglasses) on maintaining high illuminance levels to prevent myopia. Methods A child-sized mannequin head was developed to measure light illuminance levels with and without sun-protective equipment, across a wide range of environments in Singapore, outdoors (open park, under a tree, street) and indoors (under a fluorescent illumination with window, under white LED-based lighting without window). A comparison was made between indoor and outdoor light levels that are experienced while children are involved in day-to-day activities. Results Outdoor light levels were much higher (11,080-18,176 lux) than indoors (112-156 lux). The higher lux levels protective of myopia (>1000 lux) were measured at the tree shade (5556-7876 lux) and with hat (4112-8156 lux). Sunglasses showed lux levels between 1792 and 6800 lux. Although with sunglasses readings were lower than tree shade and hat, light levels were still 11 to 43 times higher than indoors. Conclusions Recommendations on spending time outdoors for myopia prevention with adequate sun protection should be provided while partaking in outdoor activities, including protection under shaded areas, wearing a hat or sunglasses, sunscreen, and adequate hydration. Translational Relevance Light levels outdoors were higher than indoors and above the threshold illuminance for myopia prevention even with adequate sun-protective measures.
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Affiliation(s)
| | - Aaron Teo
- University of Southampton Malaysia (UoSM), Johor, Malaysia
| | | | - Hla M Htoon
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Eye ACP, Singapore
| | - Raymond P Najjar
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Eye ACP, Singapore
| | - Daniel P Spiegel
- Vision Sciences, Essilor R&D, Center for Innovation and Technology, Singapore
| | - Suan-Hui Pu
- University of Southampton Malaysia (UoSM), Johor, Malaysia
| | - Seang-Mei Saw
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School, Eye ACP, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
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19
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Abstract
BACKGROUND Glaucoma affects more than 70 million people worldwide, with about 10% being bilaterally blind, making it the leading cause of irreversible blindness globally. In patients with advanced glaucoma or those who have failed medical treatment without achieving adequate intraocular pressure (IOP) control, trabeculectomy (glaucoma filtration surgery where an ostium is created into the anterior chamber from underneath a partial thickness scleral flap to allow for aqueous flow out of the anterior chamber intointo the subconjunctival space forming a filtering bleb) and aqueous shunt surgery for more complex and refractory cases remain the mainstay therapies. Proliferation of fibrous tissue around an implanted aqueous shunt may block the diffusion of aqueous humour. Mitomycin C (MMC) is one of two commonly used adjunct antifibrotic agents used during aqueous shunt surgery to prevent proliferation of fibrous tissue. However, the effectiveness and safety of the use of intraoperative MMC during aqueous shunt surgery has not been established. OBJECTIVES To evaluate the effectiveness and safety of MMC versus no MMC used during aqueous shunt surgery for reducing IOP in primary and secondary glaucoma. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 13 February 2018. SELECTION CRITERIA We included randomized controlled trials (RCTs) in which one group of participants received MMC during aqueous shunt surgery and another group did not. We did not exclude studies based on outcomes. DATA COLLECTION AND ANALYSIS Two review authors independently reviewed titles and abstracts from the literature searches. We obtained full-text reports of potentially relevant studies and assessed them for inclusion. Two review authors independently extracted data related to study characteristics, risk of bias, and outcomes. We used standard methodological procedures expected by Cochrane. MAIN RESULTS We included five RCTs, with a total of 333 eyes with glaucoma randomized, and identified two ongoing trials. All included trials examined the effect of MMC versus no MMC when used during aqueous shunt surgery for glaucoma. The trials included participants with different types of uncontrolled glaucoma. One study was conducted in China, one in Saudi Arabia, two in the USA, and one study was a multicenter study conducted in Brazil, Canada, Scotland, and USA. We assessed all trials as having overall unclear risk of bias due to incomplete reporting of study methods and outcomes; two of the five trials were reported only as conference abstracts.None of the included trials reported mean decrease from baseline in IOP; however, all five trials reported mean IOP at 12 months post-surgery. At 12 months, the effect of MMC on mean IOP compared with no MMC was unclear based on a meta-analysis of trials (mean difference -0.12 mmHg, 95% CI -2.16 to 2.41; low-certainty evidence). Two trial did not report sufficient information to include in meta-analysis, but reported that mean IOP was lower in the MMC group compared with the no MMC group at 12 months.None of the included trials reported mean change from baseline in visual acuity; however, one trial reported lower mean LogMAR values (better vision) in the MMC group than in the no MMC group at 12 months post-surgery. None of the included studies reported the proportion of participants with stable best-corrected visual acuity. Three trials reported that loss of vision was not significantly different between groups (no data available for meta-analysis).None of the included studies reported the proportion of participants with a postoperative hypertensive phase, which is defined as IOP > 21 mmHg within 3 months after surgery. Two trials reported adverse events (choroidal effusion, corneal edema, flat anterior chamber, and retinal detachment); however, due to small numbers of events and sample sizes, no clear difference between MMC and placebo groups was observed. AUTHORS' CONCLUSIONS We found insufficient evidence in this review to suggest MMC provides any postoperative benefit for glaucoma patients who undergo aqueous shunt surgery. Data across all five included trials were sparse and the reporting of study methods required to assess bias was inadequate. Future RCTs of this intervention should report methods in sufficient detail to permit assessment of potential bias and estimate target sample sizes based on clinically meaningful effect sizes.
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Affiliation(s)
| | - Hla M Htoon
- Singapore Eye Research InstituteSingaporeSingapore
| | - Derek S Welsbie
- Wilmer Eye Institute, Johns Hopkins University School of MedicineGlaucoma ServiceBaltimoreUSA
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20
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Huang OS, Htoon HM, Chan AM, Tan D, Mehta JS. Incidence and Outcomes of Intraoperative Descemet Membrane Perforations During Deep Anterior Lamellar Keratoplasty. Am J Ophthalmol 2019; 199:9-18. [PMID: 30391530 DOI: 10.1016/j.ajo.2018.10.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 10/24/2018] [Accepted: 10/24/2018] [Indexed: 11/30/2022]
Abstract
PURPOSE To report the incidence and outcomes of intraoperative Descemet membrane (DM) perforations during deep anterior lamellar keratoplasty (DALK). DESIGN Retrospective, consecutive, interventional case series. METHODS A retrospective audit of all DALK cases performed from 2004 to 2015 in a tertiary center, with and without intraoperative DM perforations. We excluded cases with preexisting corneal perforations before surgery. RESULTS There were a total of 540 eyes, of which 101 (18.7%) had intraoperative DM perforations. These included 79 eyes (78.2%) with microperforations and 15 eyes (14.9%) with macroperforation. The most common steps at which DM perforation occurred intraoperatively were during deep lamellar dissection (32 cases; 31.7%), air injection (27 cases; 26.7%), and suturing (21 cases; 20.8%). Management of the DM perforations included a combination of intracameral air tamponade (49 cases; 48.5%), stromal patching (10 cases; 9.9%), fibrin glue (8 cases; 7.9%), and suturing of the defect (1 case; 1.1%). There were 2 eyes (2/540; 0.37%) that were converted to penetrating keratoplasty (PK). There were no significant differences in the postoperative unaided or best-corrected visual acuity, or in the numbers of patients with postoperative graft failure, graft rejection, or subsequent surgery at postoperative years 1 and 3. CONCLUSIONS DALK cases with DM perforations intraoperatively are often able to be managed without conversion to PK. Cases with DM perforations intraoperatively have equivalent visual acuity outcomes compared to those without DM perforations, and did not have any increased risk of graft failure, rejection, or subsequent surgery at postoperative years 1 and 3.
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Affiliation(s)
- Olivia S Huang
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore
| | - Amy M Chan
- Singapore National Eye Centre, Singapore
| | - Donald Tan
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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21
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Markov PP, Eliasy A, Pijanka JK, Htoon HM, Paterson NG, Sorensen T, Elsheikh A, Girard MJ, Boote C. Bulk changes in posterior scleral collagen microstructure in human high myopia. Mol Vis 2018; 24:818-833. [PMID: 30713421 PMCID: PMC6334987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 12/28/2018] [Indexed: 11/01/2022] Open
Abstract
Purpose We aimed to characterize any bulk changes in posterior scleral collagen fibril bundle architecture in human eyes with high myopia. Methods Wide-angle X-ray scattering (WAXS) was employed to map collagen orientation at 0.5 mm × 0.5 mm spatial intervals across the posterior sclera of seven non-myopic human eyes and three eyes with high myopia (>6D of refractive error). At each sampled point, WAXS provided thickness-averaged measures of the angular distribution of preferentially aligned collagen fibrils within the tissue plane and the anisotropic proportion (the ratio of preferentially aligned to total collagen scatter). Results Non-myopic specimens featured well-conserved microstructural features, including strong uniaxial collagen alignment along the extraocular muscle insertion sites of the mid-posterior sclera and a highly anisotropic annulus of collagen circumscribing the nerve head in the peripapillary sclera. All three myopic specimens exhibited notable alterations in the peripapillary sclera, including a partial loss of circumferential collagen alignment and a redistribution of the normally observed regional pattern of collagen anisotropic proportion. Linear mixed-model analysis indicated that the mean fiber angle deviation from the circumferential orientation in the peripapillary sclera of highly myopic eyes (23.9° ± 18.2) was statistically significantly higher than that of controls (17.9° ± 12.0; p<0.05). Conclusions Bulk alterations in the normal posterior scleral collagen microstructure occur in human eyes with high myopia. These changes could reflect remodeling of the posterior sclera during axial lengthening and/or a mechanical adaption to tissue stresses induced by fluid pressure or eye movements that may be exacerbated in enlarged eyes.
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Affiliation(s)
- Petar P. Markov
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Ashkan Eliasy
- Biomechanical Engineering Group, School of Engineering, University of Liverpool, Liverpool, UK
| | - Jacek K. Pijanka
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Hla M. Htoon
- Singapore Eye Research Institute (SERI), Singapore
| | - Neil G. Paterson
- Diamond Light Source, Harwell Science and Innovation Campus, Harwell, UK
| | - Thomas Sorensen
- Diamond Light Source, Harwell Science and Innovation Campus, Harwell, UK
| | - Ahmed Elsheikh
- Biomechanical Engineering Group, School of Engineering, University of Liverpool, Liverpool, UK,NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, UK,School of Biological Science and Biomedical Engineering, Beihang University, Beijing, China
| | - Michael J.A. Girard
- Singapore Eye Research Institute (SERI), Singapore,Ophthalmic Engineering & Innovation Laboratory (OEIL), Department of Biomedical Engineering, National University of Singapore, Singapore
| | - Craig Boote
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,Ophthalmic Engineering & Innovation Laboratory (OEIL), Department of Biomedical Engineering, National University of Singapore, Singapore
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22
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Ang M, Farook M, Htoon HM, Tan D, Mehta JS. Simulated night vision after small-incision lenticule extraction. J Cataract Refract Surg 2018; 42:1173-80. [PMID: 27531294 DOI: 10.1016/j.jcrs.2016.04.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 04/25/2016] [Accepted: 04/26/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE To describe simulated night vision, night-vision symptoms, and refractive outcomes after small-incision lenticule extraction. SETTING Tertiary referral eye center, Singapore. DESIGN Prospective case series. METHODS All patients had small-incision lenticule extraction using the Visumax 500 kHz femtosecond laser system. The main outcome measure was simulated night vision logMAR corrected distance visual acuity (CDVA) using the super vision test-night vision goggle vision chart at 12 months. Secondary outcomes measures included refractive outcomes (ie, efficacy, predictability, and safety) up to 12 months and vision-related symptoms assessed using a validated questionnaire. RESULTS The study comprised 50 eyes. Overall simulated night vision was not affected (mean CDVA 0.08 logMAR ± 0.1 [SD], P = .67; mean mesopic CDVA -0.02 ± 0.1 logMAR, P = .58) after small-incision lenticule extraction at the 12-month follow-up. In low myopia, simulated night vision improved from preoperatively (mean 0.099 ± 0.07) to 12 months postoperatively (mean 0.006 ± 0.09) (P = .008). Most patients reported mild or no night-vision symptoms 3 months after surgery (score range 1.6 to 2.2). At 12 months, the overall efficacy index was 0.98 ± 0.20, with 100% of eyes attaining an uncorrected visual acuity of 20/40 or better and 86% attaining 20/20 or better. Ninety-four percent eyes were within ±1.0 diopter of the attempted correction, and the overall safety index was 1.17 ± 0.17. CONCLUSION Small-incision lenticule extraction did not affect simulated night vision or contrast sensitivity, with patients reporting no or mild night-vision symptoms. FINANCIAL DISCLOSURE None of the authors has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Marcus Ang
- From the Singapore National Eye Centre (Ang, Farook, Tan, Mehta), Singapore Eye Research Institute (Ang, Farook, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Htoon, Mehta), and the National University Health System (Tan), Singapore
| | - Mohd Farook
- From the Singapore National Eye Centre (Ang, Farook, Tan, Mehta), Singapore Eye Research Institute (Ang, Farook, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Htoon, Mehta), and the National University Health System (Tan), Singapore
| | - Hla M Htoon
- From the Singapore National Eye Centre (Ang, Farook, Tan, Mehta), Singapore Eye Research Institute (Ang, Farook, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Htoon, Mehta), and the National University Health System (Tan), Singapore
| | - Donald Tan
- From the Singapore National Eye Centre (Ang, Farook, Tan, Mehta), Singapore Eye Research Institute (Ang, Farook, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Htoon, Mehta), and the National University Health System (Tan), Singapore
| | - Jodhbir S Mehta
- From the Singapore National Eye Centre (Ang, Farook, Tan, Mehta), Singapore Eye Research Institute (Ang, Farook, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Htoon, Mehta), and the National University Health System (Tan), Singapore.
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23
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Damgaard IB, Ang M, Farook M, Htoon HM, Mehta JS. Intraoperative Patient Experience and Postoperative Visual Quality After SMILE and LASIK in a Randomized, Paired-Eye, Controlled Study. J Refract Surg 2018; 34:92-99. [PMID: 29425387 DOI: 10.3928/1081597x-20171218-01] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 12/08/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE To compare intraoperative and postoperative subjective patient experience after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK. METHODS In a prospective, randomized, paired-eye, single-masked clinical trial at Singapore National Eye Centre, 70 patients were randomly treated with SMILE and LASIK in each eye. The intraoperative questionnaire was completed immediately after surgery and included light perception and levels of anxiety, fear, and discomfort. The postoperative 1- and 3-month questionnaires evaluated severity of light sensitivity, eye discomfort, eye dryness, excessive tearing, gritty sensation, glare, halos, blurring, and fluctuations in vision. RESULTS Average discomfort scores were higher during tissue manipulation in SMILE (1.9 ± 0.9) than flap lifting in LASIK (1.59 ± 0.8) (P = .020) but comparable during docking and laser application (P > .249). Fear scores were lower in SMILE than LASIK during docking (2.6 ± 1.6 vs 3.4 ± 1.9, P = .024) but similar during occasional blackout, laser application, and lenticule/flap manipulation (P > .364). Fear scores were generally higher in patients with intraoperative suction loss (n = 3). For SMILE, light sensitivity, eye discomfort, blurring, and fluctuations in vision improved from 1 to 3 months (P < .039). For LASIK, improvements were reported for light sensitivity, eye discomfort, eye dryness, gritty sensation, and fluctuations in vision from 1 to 3 months (P < .046). At 1 month, patients experienced more blurring after SMILE than LASIK (2.1 ± 0.8 vs 1.8 ± 0.7, P = .025), but with no differences in any of the visual symptoms at 3 months. CONCLUSIONS Tissue manipulation may be more uncomfortable during SMILE than LASIK, but not more frightening. Subjective visual symptoms were comparable after 3 months. [J Refract Surg. 2018;34(2):92-99.].
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Abstract
BACKGROUND Cytomegalovirus (CMV) is a virus that usually affects people with reduced immunity. In recent years, this virus has been thought to cause repeated inflammation in the eye, in otherwise healthy people. This form of inflammation can cause damage to the cornea (the outer layer of the eye) or to the optic nerve by causing secondary glaucoma, or to both, leading to visual loss. OBJECTIVES Our primary objective was to assess the effects of drug therapies for the treatment of CMV-associated anterior segment inflammation.Our secondary objective was to determine the optimal dose and duration of treatment with respect to recurrence and adverse effects. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 2), MEDLINE Ovid (1946 to 21 March 2017), Embase Ovid (1947 to 21 March 2017), the ISRCTN registry (www.isrctn.com/editAdvancedSearch); searched 21 March 2017, ClinicalTrials.gov (www.clinicaltrials.gov); searched 21 March 2017, and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 21 March 2017. We did not use any date or language restrictions in the electronic searches for trials. Two review authors independently reviewed the titles and abstracts. SELECTION CRITERIA We searched for randomised controlled trials (RCTs) on the management of CMV-associated anterior segment inflammation. DATA COLLECTION AND ANALYSIS We planned to have two review authors independently extract data from reports of included studies and analyse data based on methods expected by Cochrane. MAIN RESULTS We did not identify any RCTs that met our inclusion criteria. AUTHORS' CONCLUSIONS There is currently no good-quality evidence on the management of CMV-associated anterior segment inflammation. Ideally, a well-designed RCT is needed to evaluate the effectiveness of different anti-CMV medications as well as the optimal dose and duration.
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Affiliation(s)
- Arundhati Anshu
- Singapore National Eye Centre11 Third Hospital AvenueSingaporeSingapore168751
- Singapore Eye Research InstituteSingaporeSingapore
| | - Donald Tan
- Singapore National Eye Centre11 Third Hospital AvenueSingaporeSingapore168751
- Singapore Eye Research InstituteSingaporeSingapore
| | - Soon‐Phaik Chee
- Singapore Eye Research InstituteSingaporeSingapore
- Singapore National Eye CentreOcular Inflammation & Immunology Service11 Third Hospital AvenueSingaporeSingapore168751
| | - Jod S Mehta
- Singapore National Eye Centre11 Third Hospital AvenueSingaporeSingapore168751
- Singapore Eye Research InstituteSingaporeSingapore
| | - Hla M Htoon
- Singapore National Eye Centre11 Third Hospital AvenueSingaporeSingapore168751
- Singapore Eye Research InstituteSingaporeSingapore
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Abstract
To evaluate intraoperative decentration from pupil center and kappa intercept during small incision lenticule extraction (SMILE) and its impact on visual outcomes.This was a retrospective noncomparative case series. A total of 164 eyes that underwent SMILE at the Singapore National Eye Center were included. Screen captures of intraoperative videos were analyzed. Preoperative and 3 month postoperative vision and refractive data were analyzed against decentration.The mean preoperative spherical equivalent (SE) was -5.84 ± 1.77. The mean decentration from the pupil center and from kappa intercept were 0.13 ± 0.06 mm and 0.47mm ± 0.25 mm, respectively. For efficacy and predictability, 69.6% and 95.0% of eyes achieved a visual acuity (VA) of 20/20 and 20/30, respectively, while 83.8% and 97.2% of eyes were within ±0.5D and ±1.0D of the targeted SE. When analyzed across 3 groups of decentration from the pupil center (<0.1 mm, 0.1-0.2 mm, and >0.2 mm), there was no statistically significant association between decentration, safety, efficacy, and predictability. When analyzed across 4 groups of decentration from kappa intercept (<0.2 mm, 0.2-<0.4 mm, 0.4-<0.6 mm, and ≥0.6 mm), there was a trend toward higher efficacy for eyes with decentration of kappa intercept between 0.4 and <0.6 mm (P = .097). A total of 85.4% of eyes in the 0.4 to <0.6 mm group had unaided distance VA of 20/20 or better, as compared to only 57.8% of eyes in ≥0.6 mm group.Decentration of 0.13 mm from the pupil center does not result in compromised visual outcomes. Decentration of greater than 0.6 mm from the kappa intercept may result in compromised visual outcomes. There was a trend toward better efficacy in eyes which had decentered treatment from 0.4 to <0.6 mm from the kappa intercept. Patients with a large kappa intercept (>0.6 mm) should have their lenticule created 0.4 to 0.6 mm from the kappa intercept and not close to the pupil.
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Affiliation(s)
- John X. Wong
- Department of Ophthalmology, Tan Tock Seng Hospital, National Healthcare Group Eye Institute
| | - Elizabeth P. Wong
- Department of Ophthalmology, Tan Tock Seng Hospital, National Healthcare Group Eye Institute
| | | | - Jodhbir S. Mehta
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute
- Singapore National Eye Centre, Singapore
- Department of Clinical Sciences, Duke-NUS Graduate Medical School
- School of Material Science and Engineering and School of Mechanical and Aerospace Engineering, Nanyang Technological University
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Ho H, Htoon HM, Yam GHF, Toh LZ, Lwin NC, Chu S, Lee YS, Wong TT, Seet LF. Altered Anterior Segment Biometric Parameters in Mice Deficient in SPARC. ACTA ACUST UNITED AC 2017; 58:386-393. [DOI: 10.1167/iovs.16-20261] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
| | | | - Gary Hin-Fai Yam
- Singapore Eye Research Institute, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 4Duke-NUS Medical School Singapore, Singapore
| | | | | | | | | | - Tina T. Wong
- Singapore National Eye Centre, Singapore 2Singapore Eye Research Institute, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 4Duke-NUS Medical School Singapore, Singapore 5School of Materials Science and Engineering, Nanyang Technological University, Singapore
| | - Li-Fong Seet
- Singapore Eye Research Institute, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 4Duke-NUS Medical School Singapore, Singapore
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Huang OS, Mehta JS, Htoon HM, Tan DT, Wong TT. Incidence and Risk Factors of Elevated Intraocular Pressure Following Deep Anterior Lamellar Keratoplasty. Am J Ophthalmol 2016; 170:153-160. [PMID: 27519560 DOI: 10.1016/j.ajo.2016.07.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Revised: 07/27/2016] [Accepted: 07/30/2016] [Indexed: 11/16/2022]
Abstract
PURPOSE To report the incidence and risk factors of elevated IOP following deep anterior lamellar keratoplasty (DALK). DESIGN A retrospective case series. METHODS A retrospective study investigating the 5-year incidence of raised IOP following DALK cases performed from 2004 to 2008 in a tertiary center. Patients with less than 6 months of follow-up were excluded. Elevated IOP was defined as IOP >21 mm Hg. RESULTS An episode of elevated IOP occurred in 36.1% of cases (44/122 cases), 11.4% (n = 5) occurring within the first week. The average duration of raised IOP was 48.9 (SD: 65.5) days. Causes included pupil block from air, swollen grafts, and corticosteroid response. Surgical intervention to lower IOP was required in 3 cases (6.8%). In multivariate analyses, the use of Olopatadine 0.1% or cyclosporine eye drops before DALK (OR = 14.51, 95% CI = 1.43-147.23) and use of topical prednisolone acetate 1% compared with dexamethasone 0.1% post DALK (OR = 4.79, 95% CI = 0.73-31.52) were associated with higher rates of elevated IOP post DALK. At 5 years post DALK, 3 of 71 cases (4.48%) developed de novo glaucomatous field defects, and 1 case with pre-existing glaucoma had progression of glaucomatous field defect. CONCLUSIONS DALK was associated with a significant incidence of transiently elevated IOP postoperatively, but had a low incidence of de novo glaucoma at 5 years in our study. Risk factors for raised IOP post DALK included the use of topical prednisolone acetate 1% compared with dexamethasone 0.1%, and the use of Olopatadine 0.1% or any concentration of cyclosporine eye drops prior to DALK.
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Affiliation(s)
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore
| | - Donald T Tan
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Tina T Wong
- Singapore National Eye Centre, Singapore; Singapore Eye Research Institute, Singapore; Ophthalmology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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Tun TA, Thakku SG, Png O, Baskaran M, Htoon HM, Sharma S, Nongpiur ME, Cheng CY, Aung T, Strouthidis NG, Girard MJA. Shape Changes of the Anterior Lamina Cribrosa in Normal, Ocular Hypertensive, and Glaucomatous Eyes Following Acute Intraocular Pressure Elevation. Invest Ophthalmol Vis Sci 2016; 57:4869-4877. [PMID: 27654413 DOI: 10.1167/iovs.16-19753] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to estimate and compare changes in anterior lamina cribrosa (LC) morphology in normal, ocular hypertensive (OHT), and glaucomatous eyes following acute elevations in intraocular pressure (IOP). Methods The optic nerve heads (ONHs) of 97 subjects (17 OHT, 19 primary open-angle glaucoma [POAG], 31 primary angle-closure glaucoma [PACG], and 30 normal subjects) were imaged using optical coherence tomography (OCT). Intraocular pressure was raised twice by applying forces to the anterior sclera, using an ophthalmodynamometer. After each IOP elevation, IOP was held constant and measured; each ONH was rescanned with OCT. In each OCT volume, the anterior LC was enhanced, delineated, and its global shape index (GSI) calculated and compared across groups. Results The baseline IOP was 17.5 ± 3.5 mm Hg and was increased to 38 ± 5.9 mm Hg and then to 46.5 ± 5.9 mm Hg. At the first IOP increment, mean GSI was significantly smaller than that at baseline in normal subjects and glaucoma subjects (P < 0.05) but not in OHT subjects (P = 0.12). For the second IOP increment, the mean GSI was significantly smaller than that at baseline in normal subjects and in OHT eyes (P < 0.05). After adjusting for age, sex, and baseline IOP, the LC of POAG eyes was found to be significantly more posteriorly curved than that of normal subjects (P = 0.04). Conclusions Acute IOP elevations altered anterior LC shape in a complex nonlinear fashion. The LC of POAG eyes was more cupped following acute IOP elevations compared to that of normal subjects.
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Affiliation(s)
- Tin A Tun
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore
| | - Sri Gowtham Thakku
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore
| | - Owen Png
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 2Duke-National University of Singapore Medical School, Singapore
| | - Mani Baskaran
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 2Duke-National University of Singapore Medical School, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 2Duke-National University of Singapore Medical School, Singapore
| | - Sourabh Sharma
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 2Duke-National University of Singapore Medical School, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 2Duke-National University of Singapore Medical School, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Tin Aung
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 2Duke-National University of Singapore Medical School, Singapore 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Nicholas G Strouthidis
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 4National Institute of Health Research Biomedical Research Centre, Moorfields Eye Hospital, National Health Service Foundation Trust, and University College London (UCL) Institute of Ophthalmology, London, United Kingdom 5Discipline of Clinical Ophthalmology and Eye Health, University of Sydney, Sydney, New South Wales, Australia
| | - Michaël J A Girard
- Singapore Eye Research Institute and Singapore National Eye Centre Singapore 6Ophthalmic Engineering and Innovation Laboratory, Department of Biomedical Engineering, National University of Singapore, Singapore
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Ang M, Ho H, Fenwick E, Lamoureux E, Htoon HM, Koh J, Tan D, Mehta JS. Vision-related quality of life and visual outcomes after small-incision lenticule extraction and laser in situ keratomileusis. J Cataract Refract Surg 2016; 41:2136-44. [PMID: 26703289 DOI: 10.1016/j.jcrs.2015.10.049] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 02/20/2015] [Accepted: 02/22/2015] [Indexed: 10/22/2022]
Abstract
PURPOSE To compare vision-related quality of life (VRQoL) scores and clinical outcomes between small-incision lenticule extraction and laser in situ keratomileusis (LASIK). SETTING Singapore National Eye Centre, Singapore. DESIGN Prospective study. METHODS Patients had small-incision lenticule extraction using the Visumax 500 kHz femtosecond laser; or LASIK excimer ablation with the Wavelight Allegretto 400 Hz laser. Primary outcomes were 3-month predictability, efficacy, and safety. Secondary outcomes were intraoperative experience, visual symptoms, and VRQoL (validated Quality of Life Impact of Refractive Correction [QIRC] questionnaire) in 25 a subgroup of patients in each group. Following Rasch analysis, "Functional" and "Emotional," QIRC dimensions were analysed separately. RESULTS At 3 months, predictability (82.5% versus 85.3%, ±0.5 diopters attempted correction, P =.453), safety index (1.13 ± 0.19 [SD] versus 1.07 ± 0.16, P = .158), and efficacy index (0.91 ± 0.21 versus 0.97 ± 0.19; P = .002) were found when comparing small-incision lenticule extraction (172 eyes) and LASIK (matched 688 eyes). Intraoperative experience between groups was not statistically different; visual fluctuations (P = .020) and episodes of visual blurring (P = .008) were greater after small-incision lenticule extraction than after LASIK at 1 month but not at 3 months. There was no difference in "functional" (66.7 ± 15.7 versus 55.3 ± 22.2, P = .064) and "emotional" (42.7 ± 23.2 versus 37.9 ± 23.8, P = .394) QIRC dimensions between the 2 groups (25 patients in each group) at 3 months. CONCLUSION The study, 3-month predictability, safety, and VRQL scores were not statistically different between small-incision lenticule extraction and LASIK. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Marcus Ang
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia
| | - Henrietta Ho
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia
| | - Eva Fenwick
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia
| | - Ecosse Lamoureux
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia
| | - Hla M Htoon
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia
| | - Jane Koh
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia
| | - Donald Tan
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia
| | - Jodhbir S Mehta
- From the Singapore National Eye Centre (Ang, Ho, Koh, Tan, Mehta), the Singapore Eye Research Institute (Ang, Ho, Lamoureux, Htoon, Tan, Mehta), Duke-NUS Graduate Medical School (Lamoureux, Htoon, Tan, Mehta), and the National University Health System (Tan), Singapore; the Centre for Eye Research Australia (Fenwick, Lamoureux), University of Melbourne, Melbourne, Australia.
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Seet LF, Narayanaswamy A, Finger SN, Htoon HM, Nongpiur ME, Toh LZ, Ho H, Perera SA, Wong TT. Distinct iris gene expression profiles of primary angle closure glaucoma and primary open angle glaucoma and their interaction with ocular biometric parameters. Clin Exp Ophthalmol 2016; 44:684-692. [PMID: 26988898 PMCID: PMC5111746 DOI: 10.1111/ceo.12743] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 02/02/2023]
Abstract
Background This study aimed to evaluate differences in iris gene expression profiles between primary angle closure glaucoma (PACG) and primary open angle glaucoma (POAG) and their interaction with biometric characteristics. Design Prospective study. Participants Thirty‐five subjects with PACG and thirty‐three subjects with POAG who required trabeculectomy were enrolled at the Singapore National Eye Centre, Singapore. Methods Iris specimens, obtained by iridectomy, were analysed by real‐time polymerase chain reaction for expression of type I collagen, vascular endothelial growth factor (VEGF)‐A, ‐B and ‐C, as well as VEGF receptors (VEGFRs) 1 and 2. Anterior segment optical coherence tomography (ASOCT) imaging for biometric parameters, including anterior chamber depth (ACD), anterior chamber volume (ACV) and lens vault (LV), was also performed pre‐operatively. Main Outcome Measures Relative mRNA levels between PACG and POAG irises, biometric measurements, discriminant analyses using genes and biometric parameters. Results COL1A1, VEGFB, VEGFC and VEGFR2 mRNA expression was higher in PACG compared to POAG irises. LV, ACD and ACV were significantly different between the two subgroups. Discriminant analyses based on gene expression, biometric parameters or a combination of both gene expression and biometrics (LV and ACV), correctly classified 94.1%, 85.3% and 94.1% of the original PACG and POAG cases, respectively. The discriminant function combining genes and biometrics demonstrated the highest accuracy in cross‐validated classification of the two glaucoma subtypes. Conclusions Distinct iris gene expression supports the pathophysiological differences that exist between PACG and POAG. Biometric parameters can combine with iris gene expression to more accurately define PACG from POAG.
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Affiliation(s)
- Li-Fong Seet
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore
| | | | | | - Hla M Htoon
- Singapore Eye Research Institute, Singapore.,Duke-NUS Graduate Medical School, Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore
| | | | | | - Shamira A Perera
- Singapore Eye Research Institute, Singapore.,Singapore National Eye Centre, Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore.,Singapore National Eye Centre, Singapore.,School of Materials Science and Engineering, Nanyang Technological University, Singapore
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31
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Narayanaswamy A, Baskaran M, Perera SA, Nongpiur ME, Htoon HM, Tun TA, Wong TT, Goh D, Su DH, Chew PTK, Ho CL, Aung T. Argon Laser Peripheral Iridoplasty for Primary Angle-Closure Glaucoma: A Randomized Controlled Trial. Ophthalmology 2015; 123:514-21. [PMID: 26707418 DOI: 10.1016/j.ophtha.2015.11.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 11/02/2015] [Accepted: 11/02/2015] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To determine the effectiveness of argon laser peripheral iridoplasty (ALPI) in primary angle closure (PAC) and primary angle-closure glaucoma (PACG). DESIGN Randomized controlled trial. PARTICIPANTS Eighty PAC or PACG subjects who underwent laser iridotomy (LI) and had at least 180° of persistent appositional angle closure and intraocular pressure (IOP) of more than 21 mmHg were enrolled. METHODS Subjects were randomized to receive either 360° ALPI (Visulas 532s; Carl Zeiss Meditec, Jena, Germany) or medical therapy (Travoprost 0.004%; Alcon-Couvreur, Puurs, Antwerp, Belgium). Repeat ALPI was performed if the IOP reduction was less than 20% from baseline along with inadequate angle widening at the month 1 or month 3 visit. Intraocular pressure was controlled with systematic addition of medications when required. MAIN OUTCOME MEASURES The primary outcome measure was success rates after ALPI at 1 year. Complete success was defined as an IOP of 21 mmHg or less without medication, and qualified success was defined as an IOP of 21 mmHg or less with medication. Failure was defined as an IOP more than 21 mmHg despite additional medications or requiring glaucoma surgery. RESULTS Forty subjects (51 eyes) were randomized to ALPI and 40 subjects (55 eyes) were randomized to medical therapy. Complete success (IOP ≤21 mmHg without medication) was achieved in 35.0% eyes of the ALPI group compared with 85.0% of eyes in the prostaglandin analog (PGA) group (P < 0.001), and qualified success (IOP ≤21 mmHg with medication) was achieved in 35.0% and 7.5%, respectively (P = 0.003). The IOP decreased by 4.9 mmHg (95% confidence interval [CI], 3.5-6.3 mmHg) in the ALPI group (P < 0.001) and by 6.1 mmHg (95% CI, 5.1-7.1 mmHg) in the medication group (P < 0.001). A failure rate of 30.0% was noted in the ALPI group compared with 7.5% in the medication group (P = 0.01). No treatment-related complications were recorded in either group. CONCLUSIONS After 1 year, ALPI was associated with higher failure rates and lower IOP reduction compared with PGA therapy in eyes with persistent appositional angle closure and raised IOP after LI.
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Affiliation(s)
- Arun Narayanaswamy
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Mani Baskaran
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Shamira A Perera
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Tin A Tun
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Tina T Wong
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - David Goh
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Daniel H Su
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Paul T K Chew
- Department of Ophthalmology, National University Hospital, National University Health System, Singapore, Republic of Singapore
| | - Ching-Lin Ho
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore
| | - Tin Aung
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore, Republic of Singapore; Department of Ophthalmology, National University Hospital, National University Health System, Singapore, Republic of Singapore.
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Mi H, Tan N, Ang M, Htoon HM, Mehta JS. Comparison of anterior and posterior topographic analysis between 3 imaging systems. J Cataract Refract Surg 2015; 41:2533-45. [DOI: 10.1016/j.jcrs.2015.05.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/19/2015] [Accepted: 05/25/2015] [Indexed: 11/16/2022]
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Affiliation(s)
- Valencia Hui Xian Foo
- National University of Singapore; Yong Loo Lin School of Medicine; Singapore Singapore
| | - Shamira A Perera
- Singapore National Eye Centre; Glaucoma Service; Singapore Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute; Singapore Singapore
| | - Derek S Welsbie
- Wilmer Eye Institute, Johns Hopkins University School of Medicine; Glaucoma Service; Baltimore USA
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Tun TA, Sun CH, Baskaran M, Girard MJA, de Leon JMS, Cheng CY, Htoon HM, Wong TY, Aung T, Strouthidis NG. Determinants of optical coherence tomography-derived minimum neuroretinal rim width in a normal Chinese population. Invest Ophthalmol Vis Sci 2015; 56:3337-44. [PMID: 26024117 DOI: 10.1167/iovs.15-16786] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize an optical coherence tomography (OCT)-derived parameter, Bruch's membrane opening-minimum rim width (BMO-MRW), and its association with demographic and clinical parameters in normal Chinese subjects. METHODS Right eyes of 466 consecutive healthy subjects from a population-based study of Singaporean Chinese underwent Cirrus OCT imaging. The retinal internal limiting membrane (ILM) and BMO were automatically delineated using the built-in Cirrus algorithm. The standard 36 interpolated radial B-scans (72 BMO points, 5° increments) of each optic nerve head were manually extracted from the central circle (3.46-mm diameter). We used Matlab to measure the shortest distance from the BMO points to the ILM. Associations of BMO-MRW with demographic and clinical parameters were evaluated using marginal general estimating equations analysis. RESULTS There was a slight preponderance of male subjects (50.9%), with a mean age of 54.8 ± 7.63 years. Mean BMO-MRW was 304.67 ± 58.96 μm (range, 173.32-529.23 μm), which was highly associated with OCT-derived disc area (DA) (β = -91.78, P < 0.001) and rim area (RA) (β = 194.31, P < 0.001), followed by spherical refractive error (SRE) (β = -2.23, P = 0.02) and retinal nerve fiber layer (RNFL) thickness (β = 0.5, P = 0.04), after adjusting for the associated factors such as age, sex, intraocular pressure (IOP), and vertical cup-disc ratio (VCDR). CONCLUSIONS Disc area and RA had the strongest association with BMO-MRW, followed by SRE and RNFL thickness. The availability of this normative database will facilitate optic nerve head assessment using the BMO-MRW parameter in Chinese subjects.
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Affiliation(s)
- Tin A Tun
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore
| | - Chen-Hsin Sun
- Duke-National University of Singapore (NUS) Graduate Medical School, National University of Singapore, Singapore 3Department of Ophthalmology, National University Health System, Singapore
| | - Mani Baskaran
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore 2Duke-National University of Singapore (NUS) Graduate Medical School, National University of Singapore, Singapore 4Department of Ophthalmology, Yong Loo Lin School of Medicine
| | - Michael J A Girard
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore 5In Vivo Biomechanics Laboratory, Department of Biomedical Engineering, National University of Singapore, Singapore
| | | | - Ching-Yu Cheng
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore 2Duke-National University of Singapore (NUS) Graduate Medical School, National University of Singapore, Singapore 4Department of Ophthalmology, Yong Loo Lin School of Medicine
| | - Hla M Htoon
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore 2Duke-National University of Singapore (NUS) Graduate Medical School, National University of Singapore, Singapore
| | - Tien Y Wong
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore 2Duke-National University of Singapore (NUS) Graduate Medical School, National University of Singapore, Singapore 4Department of Ophthalmology, Yong Loo Lin School of Medicine
| | - Tin Aung
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore 2Duke-National University of Singapore (NUS) Graduate Medical School, National University of Singapore, Singapore 4Department of Ophthalmology, Yong Loo Lin School of Medicine
| | - Nicholas G Strouthidis
- Singapore Eye Research Institute and Singapore National Eye Centre, Singapore 7National Institute for Health Research (NIHR) Biomedical Research Centre, Moorfields Eye Hospital National Health Service (NHS) Foundation Trust and University College London (
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Kumaran A, Htoon HM, Tan D, Chia A. Analysis of Changes in Refraction and Biometry of Atropine- and Placebo-Treated Eyes. ACTA ACUST UNITED AC 2015; 56:5650-5. [DOI: 10.1167/iovs.14-14716] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Arjunan Kumaran
- Yong Loo Lin School of Medicine National University of Singapore, Singapore
| | | | - Donald Tan
- Singapore Eye Research Institute, Singapore 3Singapore National Eye Centre, Singapore 4Duke NUS Graduate Medical School, Singapore 5Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Audrey Chia
- Singapore Eye Research Institute, Singapore 3Singapore National Eye Centre, Singapore 4Duke NUS Graduate Medical School, Singapore
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Ang M, Mehta JS, Chan C, Htoon HM, Koh JCW, Tan DT. Refractive lenticule extraction: transition and comparison of 3 surgical techniques. J Cataract Refract Surg 2015; 40:1415-24. [PMID: 25135532 DOI: 10.1016/j.jcrs.2013.12.026] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 12/09/2013] [Accepted: 12/17/2013] [Indexed: 11/19/2022]
Abstract
PURPOSE To describe the transition and outcomes of 3 refractive lenticule extraction (ReLEx) techniques: femtosecond lenticule extraction (FLEx), small-incision lenticule extraction (SMILE), and pseudo small-incision lenticule extraction. SETTING Singapore National Eye Center, Singapore. DESIGN Prospective comparative case series. METHODS Refractive lenticule extraction was performed between March 1, 2010, and November 1, 2012, using the Visumax 500 kHz femtosecond laser system. The main outcome measures were the refractive efficacy, predictability, and safety over 12 months. RESULTS The study enrolled 88 eyes. All 3 refractive lenticule extraction techniques yielded good refractive outcomes and stability over 12 months. Three months postoperatively, the mean overall efficacy index of refractive lenticule extraction was 0.89±0.22 (SD), with 95.5% of eyes attaining an uncorrected distance visual acuity (UDVA) of better than 20/40 and 60.2% of better than 20/20. Of all eyes, 95.5% were within ±1.00 diopter (D) and 78.4% within ±0.50 D of the attempted correction. The mean overall safety index was 1.06±0.17. At 3 months, all small-incision lenticule extraction eyes and 96.7% of pseudo small-incision lenticule extraction eyes had a UDVA of 20/40 or better, while femtosecond lenticule extraction eyes had a lower efficacy index (87.0%). However, efficacy was comparable in all 3 groups by 12 months (mean 0.87±0.04 [standard error of the mean]; P=1.00). CONCLUSION The efficacy, safety, and predictability profiles of the 3 refractive lenticule extraction techniques were good over a 12-month follow-up. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Marcus Ang
- From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore
| | - Jodhbir S Mehta
- From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore
| | - Cordelia Chan
- From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore
| | - Hla M Htoon
- From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore
| | - Jane C W Koh
- From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore
| | - Donald T Tan
- From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore.
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Tsai ASH, Boey PY, Htoon HM, Wong TT. Bleb needling outcomes for failed trabeculectomy blebs in Asian eyes: a 2-year follow up. Int J Ophthalmol 2015; 8:748-53. [PMID: 26309874 DOI: 10.3980/j.issn.2222-3959.2015.04.19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 12/24/2014] [Indexed: 11/02/2022] Open
Abstract
AIM To describe the outcomes of bleb needling in primary glaucoma in an Asian tertiary eye centre over a 2y period. To compare the success rates between primary angle-closure glaucoma (PACG) and primary open angle glaucoma (POAG). Lastly, to identify factors associated with success of bleb needling. METHODS This was a retrospective review of 227 patients who underwent bleb needling between June 2009 and June 2011 in Singapore National Eye Centre. The 5-fluorouracil (5-FU) augmented bleb needling was performed either at the slit lamp or in the operating theatre. Repeat bleb needlings were performed as necessary. Complete success was defined as maintenance of intraocular pressure (IOP) ≥6 mm Hg and ≤21 mm Hg, in the absence of further surgery or use of antiglaucoma medication. Qualified success met the above criteria with or without use of antiglaucoma medications. RESULTS One hundred and seventy-five eyes completed the two-year follow up. Sixty-nine percent of participants had POAG and 31% had PACG. The mean interval between filtering surgery and bleb needling was 299.9±616.4d for POAG and 167.1±272.2d for PACG. Mean needling attempts were 1.9±1.4 and 2±1.6 for POAG and PACG respectively. In general, there was a statistically significant reduction of IOP ranging from 21.9% to 26.8% from month 1 through to month 24. The complete success rates at month 6 were 70.0% for POAG and 65.7% for PACG. At month 12, this decreased to 62.2% for POAG and PACG and at month 24, 57.9% for POAG and 63.0% for PACG respectively. The qualified success rates at month 6 for POAG and PACG were 23.8% and 29.9% respectively, 32.2% and 29.2% at month 12, and 34.7% and 29.6% at month 24. The success rates between POAG and PACG were not significantly different (P>0.05 for complete and qualified success at months 6, 12 and 24). An increased number of needlings and higher pre-needling IOP were associated with failure. CONCLUSION The 5-FU augmented bleb needling within one year of trabeculectomy in Asian eyes can provide clinically significant IOP lowering of more than 20% for 2y. POAG and PACG had similar complete success rates (58% and 63% respectively). Factors associated with greater risk of procedure failure included increased number of needlings and higher pre-needling IOP. Asian eyes have a greater propensity for scarring but bleb needling, if performed in a timely manner can rescue bleb function.
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Affiliation(s)
- Andrew S H Tsai
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Pui Yi Boey
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, Singapore
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Ang M, Lim F, Htoon HM, Tan D, Mehta JS. Visual acuity and contrast sensitivity following Descemet stripping automated endothelial keratoplasty. Br J Ophthalmol 2015; 100:307-11. [DOI: 10.1136/bjophthalmol-2015-306975] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 06/28/2015] [Indexed: 11/03/2022]
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Narayanaswamy A, Leung CK, Istiantoro DV, Perera SA, Ho CL, Nongpiur ME, Baskaran M, Htoon HM, Wong TT, Goh D, Su DH, Belkin M, Aung T. Efficacy of selective laser trabeculoplasty in primary angle-closure glaucoma: a randomized clinical trial. JAMA Ophthalmol 2015; 133:206-12. [PMID: 25429421 DOI: 10.1001/jamaophthalmol.2014.4893] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Selective laser trabeculoplasty (SLT) should be explored as a therapeutic option in eyes with angle closure. OBJECTIVE To assess the intraocular pressure (IOP)-lowering efficacy of SLT in eyes with primary angle closure (PAC) and PAC glaucoma (PACG). DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial at tertiary eye care institutions of 100 patients diagnosed as having PAC or PAC glaucoma in which the angles had opened at least 180° (visible posterior trabecular meshwork on gonioscopy) after laser iridotomy. Recruitment and baseline were completed from June 2009 to April 2012 and 6-month follow-up was completed from December 2009 to November 2012. INTERVENTIONS Eligible patients with a baseline IOP greater than 21 mm Hg were randomized to either SLT or prostaglandin analog (PGA; travoprost, 0.004%). The SLT was repeated if the IOP reduction was less than 20.0% from baseline at the 1- or 3-month follow-up visit. MAIN OUTCOMES AND MEASURES The primary outcome measure was the change in IOP from baseline to the final follow-up visit (at 6 months). The frequency of additional postoperative treatments and complications were secondary outcomes. RESULTS Fifty patients (96 eyes) were randomized to SLT and 50 patients (99 eyes) to PGA medical therapy. At 6 months, 49 patients in the SLT group and 47 in the PGA group completed follow-up. Analysis was based on intent to treat. At 6 months, IOP decreased by 4.0 mm Hg (95% CI, 3.2-4.8) in the SLT group (P < .001) and by 4.2 mm Hg (95% CI, 3.5-4.9) in the PGA group (P < .001). There were no differences between the SLT and PGA groups in the absolute mean reduction of IOP (4.0 vs 4.2 mm Hg, respectively; P = .78) or in the percentage of reduction in IOP (16.9% vs 18.5%, respectively; P = .52). Complete success (IOP ≤21 mm Hg without medications) was achieved in 60.0% eyes of the SLT group, compared with 84.0% of eyes in the PGA group (P = .008). No patients required glaucoma surgery. Additional medications were required in 22.0% of patients in the SLT group compared with 8.0% in the PGA group (P = .05). One patient in the SLT group (2.0%) had a transient posttreatment IOP spike greater than 5 mm Hg. The mean endothelial cell count showed a significant decrease from baseline in the SLT arm (4.8% decrease; P = .001). No other events such as persistent uveitis or increase in peripheral anterior synechiae were noted in eyes that underwent SLT. Two patients in the PGA group exited owing to drug-related complications (1 patient with uveitis and 1 with allergic conjunctivitis). CONCLUSIONS AND RELEVANCE Eyes with PAC or PACG respond to SLT in the short term, but the overall long-term therapeutic effectiveness needs further evaluation. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01004900.
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Affiliation(s)
- Arun Narayanaswamy
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Christopher K Leung
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong
| | | | - Shamira A Perera
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Ching-Lin Ho
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Mani Baskaran
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Tina T Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - David Goh
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Daniel H Su
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Michael Belkin
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore4Goldschleger Eye Research Institute, Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore5Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Tun TA, Baskaran M, Perera SA, Htoon HM, Aung T, Husain R. Swept-source optical coherence tomography assessment of iris–trabecular contact after phacoemulsification with or without goniosynechialysis in eyes with primary angle closure glaucoma. Br J Ophthalmol 2015; 99:927-31. [DOI: 10.1136/bjophthalmol-2014-306223] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 12/21/2014] [Indexed: 11/04/2022]
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Affiliation(s)
- Donald Tan
- Cornea Service and Refractive Service, Singapore National Eye Centre, Singapore, Singapore Singapore Eye Research Institute, Singapore, Singapore Department of Ophthalmology, National University Health System, Singapore, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore, Singapore
| | - Marcus Ang
- Cornea Service and Refractive Service, Singapore National Eye Centre, Singapore, Singapore Singapore Eye Research Institute, Singapore, Singapore
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Tun TA, Baskaran M, Perera SA, Chan AS, Cheng CY, Htoon HM, Sakata LM, Cheung CY, Aung T. Sectoral variations of iridocorneal angle width and iris volume in Chinese Singaporeans: a swept-source optical coherence tomography study. Graefes Arch Clin Exp Ophthalmol 2014; 252:1127-32. [PMID: 24781879 DOI: 10.1007/s00417-014-2636-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 03/18/2014] [Accepted: 04/07/2014] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To assess variations in the iridocorneal angle width and iris volume in Chinese subjects using swept-source optical coherence tomography (SS-OCT). METHODS Consecutive subjects, aged 40-80 years, with no previous ophthalmic problems were recruited from a population-based study of Chinese Singaporeans. All subjects underwent 360° SS-OCT (SS-1000 CASIA, Tomey Corporation, Nagoya, Japan) angle imaging and gonioscopy in one randomly selected eye in the dark. For each eye, 16 frames (11.25° apart) were selected for analysis from 128 cross-sectional images, and measurements of the trabecular iris space area 750 μm from the scleral spur (TISA750) and iris volume were made for each image. The measurements from four consecutive frames were further averaged as a sector of 45°. Sector-wise angle width and quadrant-wise iris volume were analyzed. RESULTS Two hundred and twelve subjects (90 with closed-angles) were examined. The majority of the subjects were female (70.7 %) with mean age 61 (±8.9) years. The TISA750 (mm(2)) of superior [0.101 (0.09)], inferior [0.105 (0.09)], superior-nasal [0.111 (0.09)] and superior-temporal [0.117 (0.09)] sectors were smaller compared with other sectors (P < 0.05). The nasal iris volume (mm(3)) was the smallest compared with other quadrants for the entire cohort [nasal 8.18 (1.2) < inferior 9.13 (1.3) < temporal 9.16 (1.2) < superior 9.33 (1.3), P < 0.001], as well as for open- and closed-angle groups. CONCLUSIONS The irido-corneal angle was narrower in the superior, inferior, superior-nasal and superior-temporal sectors compared with other sectors. Iris volume in the nasal quadrant was the smallest compared with the other quadrants.
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Affiliation(s)
- Tin A Tun
- Singapore Eye Research Institute and Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore, 168751, Singapore
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Wong TT, Novack GD, Natarajan JV, Ho CL, Htoon HM, Venkatraman SS. Nanomedicine for glaucoma: sustained release latanoprost offers a new therapeutic option with substantial benefits over eyedrops. Drug Deliv Transl Res 2014; 4:303-9. [DOI: 10.1007/s13346-014-0196-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Ang M, Li L, Chua D, Wong C, Htoon HM, Mehta JS, Tan D. Descemet's stripping automated endothelial keratoplasty with anterior chamber intraocular lenses: complications and 3-year outcomes. Br J Ophthalmol 2014; 98:1028-32. [PMID: 24676725 DOI: 10.1136/bjophthalmol-2013-304622] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
PURPOSE To describe outcomes and complications following Descemet's stripping automated endothelial keratoplasty (DSAEK) in eyes with pseudophakic bullous keratopathy (BK) while retaining the anterior chamber intraocular lenses (ACIOL). METHODS We included consecutive patients who underwent DSAEK for BK at a single tertiary centre from 1 January 2008 to 1 April 2010, from our prospective cohort (Singapore Corneal Transplant Study). We compared eyes with BK, which underwent DSAEK while retaining ACIOL (n=18), to those with DSAEK alone with the posterior chamber intraocular lenses left in place as a comparison group (n=114). Main outcome measures were endothelial cell (EC) loss and graft survival. RESULTS The percentage EC loss at 1 year was 31.9±21.3% in the DSAEK with ACIOL group compared to 24.5±21.2% in the DSAEK group (p=0.516); however, this figure was significantly greater in the DSAEK with ACIOL group at 3 years compared to the DSAEK group (55.3±29.2% vs 33.3±20.8%; p=0.01 respectively). Graft survival was also significantly poorer in the DSAEK ACIOL group compared to the DSAEK group over 3 years (log rank p=0.002). CONCLUSIONS We found that although eyes with BK and ACIOL that underwent DSAEK while retaining the ACIOL suffered EC loss which was not significantly greater at 1 year, EC loss and graft survival were significantly poorer compared to DSAEK controls at 3 years postoperatively.
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Affiliation(s)
- Marcus Ang
- Singapore National Eye Centre, Singapore, Singapore Singapore Eye Research Institute, Singapore, Singapore
| | - Lim Li
- Singapore National Eye Centre, Singapore, Singapore Singapore Eye Research Institute, Singapore, Singapore
| | - Daniel Chua
- Singapore National Eye Centre, Singapore, Singapore
| | - Cheewai Wong
- Singapore National Eye Centre, Singapore, Singapore Singapore Eye Research Institute, Singapore, Singapore
| | - Hla M Htoon
- Singapore Eye Research Institute, Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore, Singapore Singapore Eye Research Institute, Singapore, Singapore Department of Ophthalmology, National University Health System, Singapore, Singapore Duke, NUS Graduate Medical School, Singapore, Singapore
| | - Donald Tan
- Singapore National Eye Centre, Singapore, Singapore Singapore Eye Research Institute, Singapore, Singapore Department of Ophthalmology, National University Health System, Singapore, Singapore
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Narayanaswamy A, Perera SA, Htoon HM, Hoh ST, Seah SK, Wong TT, Aung T. Efficacy and safety of collagen matrix implants in phacotrabeculectomy and comparison with mitomycin C augmented phacotrabeculectomy at 1 year. Clin Exp Ophthalmol 2014; 41:552-60. [PMID: 23279607 DOI: 10.1111/ceo.12058] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 11/30/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND To assess the efficacy and safety of collagen matrix implant (Ologen) in phacotrabeculectomy. DESIGN Prospective, non-randomized, comparative study. PARTICIPANTS Sixty-six Asian patients. METHODS Thirty three consecutive patients underwent phacotrabeculectomy with Ologen implant and intraocular lens implantation, and 33 subjects recruited as controls underwent surgery with mitomycin C augmentation. MAIN OUTCOME MEASURES The primary outcome measure was postoperative intraocular pressure at month 12. Additional postoperative treatments, such as bleb needling, and adverse events were secondary outcomes. RESULTS The overall percentage reduction in intraocular pressure was 13% (95% confidence interval 6.7-19.2) in the Ologen group and 26% (95% confidence interval 14.8-37.9) in the mitomycin C group (P = 0.05). At 1 year after surgery (after adjusting for baseline differences), intraocular pressure decreased by 4.2 mmHg (95% confidence interval 2.8-5.6 mmHg) and 5.6 mmHg (95% confidence interval 4.2-7.0 mmHg), respectively (P = 0.16). Needling with 5-fluorouracil was required more often in the Ologen group (39% vs. 6%; P = 0.003). There was similar frequency (<10%) of adverse events in both groups, and there were no complications directly related to the Ologen implant. The blebs in the mitomycin C group had greater central area (P = 0.005), maximal area (P = 0.01) and height (P = 0.005), and were less vascular (P = 0.023) than the Ologen blebs. CONCLUSIONS At 1 year, the overall performance of Ologen in combined phacotrabeculectomy was suboptimal compared with combined surgery with mitomycin C. Eyes in the Ologen group required more frequent bleb needling procedures.
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Chan EW, Wong TT, Htoon HM, Ho CL, Tan DT, Mehta JS. De novo ocular hypertension after Descemet stripping endothelial keratoplasty: comparative 3-year incidence, risk factors, and outcomes. Clin Ophthalmol 2013; 7:1829-41. [PMID: 24092962 PMCID: PMC3788681 DOI: 10.2147/opth.s50584] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To compare the 3-year incidence of de novo ocular hypertension (OHT) after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK). For DSAEK, to evaluate predictors for OHT and 2-year outcomes after OHT development. METHODS This was a review of the prospective Singapore Corneal Transplant Study at a single tertiary referral center. Consecutive DSAEKs and PKs for Fuchs' endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK) in eyes without pre-existing glaucoma were analyzed. OHT incidence after DSAEK and PK were compared using Kaplan-Meier survival analysis, and OHT risk factors identified using Cox proportional regression. OHT was defined: intraocular pressure (IOP) ≥ 24 mmHg or ≥ 10 mmHg from baseline. Secondary outcomes 2 years after OHT development in DSAEK were rates of glaucoma medical therapy failure, IOP success, graft failure and rejection, and best-spectacle corrected visual acuity (BSCVA). RESULTS There were 108 (96.4%) DSAEKs and 216 (96%) PKs. The 1-, 2- and 3-year de novo OHT incidence was not significantly different between DSAEK (36.1%, 47.2%, 47.2%, respectively) and PK (35.7%, 44.9%, 45.8%, respectively; P = 0.914). OHT incidence did not differ in subgroup analyses of multiple clinical variables (P > 0.1). OHT predictors after DSAEK were: fellow eye glaucoma (hazard ratio [HR] 3.20, P = 0.004), age <60 years (HR 2.41, P = 0.016), concurrent goniosynechiolysis (HR 3.29, P = 0.021), post-graft complications or procedures (HR 2.85, P = 0.006). Two years after OHT onset, 29.7% of DSAEKs failed glaucoma medical therapy requiring trabeculectomy. Complete and qualified IOP success was achieved in 23.5% and 76.5%, respectively. Graft failure developed in 9.8% and graft rejection in 5.9%. At 6 months, 1, and 2 years from OHT onset, 86.3%, 88.3%, and 92.1% achieved BSCVA 20/40, respectively. CONCLUSION DSAEK and PK have comparable OHT risks. A significant 30% of DSAEK eyes with OHT require filtration surgery. Effective IOP control and good graft and visual outcomes are achieved with treatment.
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Affiliation(s)
- Errol W Chan
- Department of Ophthalmology, National University Health System, Singapore
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Shei W, Liu J, Htoon HM, Aung T, Vithana EN. Differential expression of the Slc4 bicarbonate transporter family in murine corneal endothelium and cell culture. Mol Vis 2013; 19:1096-106. [PMID: 23734078 PMCID: PMC3668641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 05/22/2013] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To characterize the relative expression levels of all the solute carrier 4 (Slc4) transporter family members (Slc4a1-Slc4a11) in murine corneal endothelium using real-time quantitative (qPCR), to identify further important members besides Slc4a11 and Slc4a4, and to explore how close to the baseline levels the gene expressions remain after cells have been subjected to expansion and culture. METHODS Descemet's membrane-endothelial layers of 8-10-week-old C57BL6 mice were stripped from corneas and used for both primary cell culture and direct RNA extraction. Total RNA (from uncultured cells as well as cultured cells at passages 2 and 7) was reverse transcribed, and the cDNA was used for real time qPCR using specific primers for all the Slc4 family members. The geNorm method was applied to determine the most stable housekeeping genes and normalization factor, which was calculated from multiple housekeeping genes for more accurate and robust quantification. RESULTS qPCR analyses revealed that all Slc4 bicarbonate transporter family members were expressed in mouse corneal endothelium. Slc4a11 showed the highest expression, which was approximately three times higher than that of Slc4a4 (3.4±0.3; p=0.004). All Slc4 genes were also expressed in cultured cells, and interestingly, the expression of Slc4a11 in cultured cells was significantly reduced by approximately 20-fold (0.05±0.001; p=0.000001) in early passage and by approximately sevenfold (0.14±0.002; p=0.000002) in late passage cells. CONCLUSIONS Given the known involvement of SLC4A4 and SLC4A11 in corneal dystrophies, we speculate that the other two highly expressed genes in the uncultured corneal endothelium, SLC4A2 and SLC4A7, are worthy of being considered as potential candidate genes for corneal endothelial diseases. Moreover, as cell culture can affect expression levels of Slc4 genes, caution and careful design of experiments are necessary when undertaking studies of Slc4-mediated ion transport in cultured cells.
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Affiliation(s)
| | - Jun Liu
- Singapore Eye Research Institute, Singapore
| | | | - Tin Aung
- Singapore Eye Research Institute, Singapore,Department of Ophthalmology, National University Health System & National University of Singapore, Singapore,Singapore National Eye Centre, Singapore
| | - Eranga N. Vithana
- Singapore Eye Research Institute, Singapore,Department of Ophthalmology, National University Health System & National University of Singapore, Singapore,Neuroscience and Behavioral Disorders (NBD) Program, Duke-NUS Graduate Medical School, Singapore
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Narayanaswamy A, Zheng C, Perera SA, Htoon HM, Friedman DS, Tun TA, He M, Baskaran M, Aung T. Variations in iris volume with physiologic mydriasis in subtypes of primary angle closure glaucoma. Invest Ophthalmol Vis Sci 2013; 54:708-13. [PMID: 23299474 DOI: 10.1167/iovs.12-10844] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To compare the changes in iris volume with pupil dilation using anterior segment optical coherence tomography (AS-OCT) in eyes of subjects with different subtypes of primary angle closure. METHODS This prospective study examined 44 fellow eyes (FA group) of subjects with previous acute primary angle closure (APAC), and 56 subjects (AC group) with chronic primary angle closure and/or primary angle closure glaucoma. All participants underwent gonioscopy and AS-OCT imaging. The iris volume, iris cross-sectional area, and pupil diameter were measured with custom semiautomated software. The main outcome variable analyzed was mean change in iris volume between light and dark conditions in a multivariate linear regression analysis. RESULTS Thirty-five eyes from the FA group (79.5%) and 50 eyes from the AC group (89.3%) were included in the final analysis. When going from light to dark, iris volume did not change significantly in eyes in the FA group (+1.50 ± 6.73 mm(3); P = 0.19), but decreased in the AC group by 1.52 ± 3.07 mm(3) (P < 0.001). This difference was significant (P = 0.01). On multivariate analysis after controlling for age, sex, baseline pupil diameter, and change in pupil diameter, age (β = -0.397; P < 0.001) and diagnostic category (AC versus FA group; β = 0.347; P < 0.001) were significant determinants of iris volume change. CONCLUSIONS With physiologic mydriasis, the iris volume decreased in eyes with chronic angle closure but remained unchanged in fellow eyes of APAC. Such variations in iris volume responses may influence the subtype of angle closure that develops.
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Affiliation(s)
- Arun Narayanaswamy
- Singapore Eye Research Institute, Singapore and Singapore National Eye Centre, Singapore
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Riau AK, Tan NYS, Angunawela RI, Htoon HM, Chaurasia SS, Mehta JS. Reproducibility and age-related changes of ocular parametric measurements in rabbits. BMC Vet Res 2012; 8:138. [PMID: 22901963 PMCID: PMC3514359 DOI: 10.1186/1746-6148-8-138] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 08/15/2012] [Indexed: 12/02/2022] Open
Abstract
Background The rabbit is a common animal model for ophthalmic research, especially corneal research. Ocular structures grow rapidly during the early stages of life. It is unclear when the rabbit cornea becomes mature and stabilized. We investigated the changes of keratometry, refractive state and central corneal thickness (CCT) with age. In addition, we studied the intra- and inter-observer reproducibility of anterior chamber depth (ACD) and anterior chamber width (ACW) measurements in rabbits using anterior segment-optical coherence tomography (AS-OCT). Results The growth of New Zealand White rabbits (n = 16) were monitored from age 1 to 12 months old. Corneal keratometric and refractive values were obtained using an autorefractor/keratometer, and CCT was measured using an AS-OCT. Keratometry and CCT changed rapidly from 1 to 7 months and appeared to be stabilizing after 8 months. The reduction of corneal curvature was approximately 1.36 diopter (D)/month from age 1 to 7 months, but the change decelerated to 0.30 D/month from age 8 to 12 months. An increase of 10 μm/month in CCT was observed from age 1 to 7 months, but the gain was reduced to less than 1 μm/month from age 8 to 12 months. There was a hyperopic shift over the span of 12 months, albeit the increase in spherical equivalent was slow and gradual. Rabbits of random age were then selected for 2 repeated ACD and ACW measurements by 2 independent and masked observers. Bland-Altman plots revealed a good agreement of ACD and ACW measurements inter- and intra-observer and the ranges of 95% limit of agreement were acceptable from a clinical perspective. Conclusions Corneal keratometry, spherical equivalent refraction and CCT changed significantly during the first few months of life of rabbits. Young rabbits have been used in a large number of eye research studies. In certain settings, the ocular parametric changes are an important aspect to note as they may alter the findings made in a rabbit experimental model. In this study, we have also demonstrated for the first time a good between observer reproducibility of measurements of ocular parameters in an animal model by using an AS-OCT.
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Affiliation(s)
- Andri K Riau
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore, Singapore
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Quek DT, Narayanaswamy AK, Tun TA, Htoon HM, Baskaran M, Perera SA, Aung T. Comparison of two spectral domain optical coherence tomography devices for angle-closure assessment. Invest Ophthalmol Vis Sci 2012; 53:5131-6. [PMID: 22786910 DOI: 10.1167/iovs.12-10132] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To compare two spectral domain optical coherence tomography (SD-OCT) devices for the identification of angle structures and the presence of angle closure. METHODS This was a prospective comparative study. Consecutive patients underwent gonioscopy and anterior segment imaging using two SD-OCT devices (iVue and Cirrus). Images were evaluated for the ability to detect angle structures such as Schwalbe's line (SL), trabecular meshwork (TM), Schlemm's canal (SC), and scleral spur (SS), and the presence of angle closure. Angle closure was defined as iris contact with the angle wall anterior to the SS on SD-OCT, and nonvisibility of the posterior TM on gonioscopy. Angle closure in an eye was defined as ≥two quadrants of closed angles. AC1 statistic was used to assess the agreement between devices. RESULTS Of the 69 subjects studied (46.4% male, 84.1% Chinese, mean age 64.0 ± 10.5 years), 40 subjects (40 eyes, 58.0%) had angle closure on gonioscopy. The most identifiable structure on Cirrus SD-OCT was the SS (82.2%) and SL on iVue SD-OCT (74.5%). Angle closure was indeterminable in 14.5% and 50.7% of Cirrus and iVue scans (P < 0.001), respectively. Interdevice agreement for angle closure was moderately strong (AC1 = 0.67), but agreement with gonioscopy was only fair (AC1 = 0.35 and 0.50 for Cirrus and iVue, respectively). CONCLUSIONS It was more difficult to determine angle closure status with iVue compared with Cirrus SD-OCT. There was fair agreement between both devices with gonioscopy for identifying angle closure.
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Affiliation(s)
- Desmond T Quek
- Singapore National Eye Centre and Singapore Eye Research Institute, Singapore
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