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Wong CSM, Mak LLY, Lee VKH, Lo RCL, Chung MMH, Chu F, Yeung CK, Yuen MF, Chan HHL. Detection of significant liver fibrosis in Chinese psoriasis patients receiving methotrexate: a comparison between transient elastography and liver histology. Hong Kong Med J 2024; 30:110-119. [PMID: 38651202 DOI: 10.12809/hkmj2210364] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024] Open
Abstract
INTRODUCTION Methotrexate (MTX) is effective for treating psoriasis and psoriatic arthritis, but its potential hepatoxicity remains a concern. Liver biopsy, the gold standard for detecting MTX-induced liver injury, is invasive and carries considerable risk. Transient elastography (TE) offers a non-invasive alternative for detecting advanced liver fibrosis. This study investigated the performance of TE in detecting MTX-induced liver fibrosis among Chinese psoriasis patients, compared with liver biopsy. METHODS This study included adult patients with clinical psoriasis. Liver stiffness measurement using TE was performed in patients receiving MTX. Exclusion criteria were known liver cirrhosis, positive viral hepatitis carrier status, or conditions influencing TE performance. Liver biopsy was performed when liver stiffness was ≥7.1 kilopascals (kPa) or when the total cumulative dose (TCD) of MTX was ≥3.5 g. RESULTS A total of 228 patients were screened; among 34 patients who met the inclusion criteria, nine (26.5%) had significant liver fibrosis (Roenigk grade ≥3a). The area under the receiver operating characteristic curve was 0.76 (95% confidence interval=0.59-0.93; P=0.021), indicating that TE had satisfactory performance in detecting liver fibrosis. A cut-off value of 7.1 kPa of liver stiffness yielded 100% sensitivity and 68% specificity. Liver fibrosis was not correlated with the TCD of MTX or the duration of MTX use; it was significantly correlated with obesity and diabetes status (body mass index ≥30 kg/m2, waist circumference ≥138 cm, and glycated haemoglobin level ≥7.8%). CONCLUSION Transient elastography is reliable and superior to the TCD for detecting liver fibrosis in Chinese psoriasis patients receiving MTX. Liver biopsy should be reserved for high-risk patients or patients with liver stiffness ≥11.7 kPa on TE.
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Affiliation(s)
- C S M Wong
- Division of Dermatology, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - L L Y Mak
- Division of Gastroenterology and Hepatology, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - V K H Lee
- Imaging and Interventional Radiology Centre, CUHK Medical Centre, Hong Kong SAR, China
| | - R C L Lo
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - M M H Chung
- Division of Dermatology, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - F Chu
- Department of Radiology, Queen Mary Hospital, Hong Kong SAR, China
- St Vincent's Hospital, Sydney, Australia
| | - C K Yeung
- Division of Dermatology, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - M F Yuen
- Division of Gastroenterology and Hepatology, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - H H L Chan
- Division of Dermatology, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Chan SSH, Choi KY, Chan HHL. Paediatric norms for photopic electroretinogram testing based on a large cohort of Chinese preschool children. BMJ Open Ophthalmol 2024; 9:e001393. [PMID: 38388004 PMCID: PMC10882341 DOI: 10.1136/bmjophth-2023-001393] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 02/03/2024] [Indexed: 02/24/2024] Open
Abstract
OBJECTIVE Full-field electroretinogram (ffERG) is an objective test to determine the electroretinal activities in response to light stimulation for investigating retinal physiology and diagnosing retinal diseases. This study aimed to establish a reference data set of photopic electroretinogram (ERG) of Chinese preschool children in Hong Kong to facilitate clinical and research studies. METHODS AND ANALYSIS Preschool children aged 3-7 years with normal vision were recruited from local kindergartens. Eye examinations, including cycloplegic spherical equivalent refraction (SER), axial length (AL) and keratometry (K) measurements, were performed. ffERGs of the International Society for Clinical Electrophysiology of Vision (ISCEV) standard photopic flash and 30-Hz flicker protocols were measured using RETeval with Sensor Strip skin electrodes. ERG waveform characteristics were extracted, and relationships between ERG, age, SER, AL and K were evaluated. RESULTS A total of 479 children completed the measurements (mean age: 5.0±0.9 years, 45.5% female). Mean, 95% CIs, 5th-95th percentile range of the ERG parameters were reported. Age was positively associated with amplitudes of b-wave and 30-Hz flicker (p<0.01), but negatively associated with implicit times of b-wave and 30-Hz flicker (p<0.01). AL was significantly associated with all amplitudes of a-wave, b-wave and 30-Hz flicker (p≤0.01) and implicit time of both a-wave and 30-Hz flicker (p<0.05). K was positively associated only with 30-Hz flicker amplitude (p=0.01), and no association between all responses and SER. CONCLUSION Reference data set of photopic ERG of Chinese preschool children was established. Cross-sectional investigations revealed associations between ERG, age, SER and AL, which were speculated to further implicate the role of retina in refractive error development.
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Affiliation(s)
- Sonia Seen-Hang Chan
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Kai Yip Choi
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Henry Ho-Lung Chan
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
- Centre for Eye and Vision Research Limited (CEVR), 17W Hong Kong Science Park, Hong Kong SAR, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong SAR, China
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Zhang P, Vafaeva O, Dolf C, Ma Y, Wang G, Cho J, Chan HHL, Marsh-Armstrong N, Zawadzki RJ. Evaluating the performance of OCT in assessing static and potential dynamic properties of the retinal ganglion cells and nerve fiber bundles in the living mouse eye. Biomed Opt Express 2023; 14:6422-6441. [PMID: 38420317 PMCID: PMC10898556 DOI: 10.1364/boe.504637] [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] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/08/2023] [Accepted: 11/11/2023] [Indexed: 03/02/2024]
Abstract
Glaucoma is a group of eye diseases characterized by the thinning of the retinal nerve fiber layer (RNFL), which is primarily caused by the progressive death of retinal ganglion cells (RGCs). Precise monitoring of these changes at a cellular resolution in living eyes is significant for glaucoma research. In this study, we aimed to assess the effectiveness of temporal speckle averaging optical coherence tomography (TSA-OCT) and dynamic OCT (dOCT) in examining the static and potential dynamic properties of RGCs and RNFL in living mouse eyes. We evaluated parameters such as RNFL thickness and possible dynamics, as well as compared the ganglion cell layer (GCL) soma density obtained from in vivo OCT, fluorescence scanning laser ophthalmoscopy (SLO), and ex vivo histology.
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Affiliation(s)
- Pengfei Zhang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, 116024, China
- UC Davis EyePod Small Animals Ocular Imaging Laboratory, University of California Davis, Davis, CA 95616, USA
| | - Olga Vafaeva
- Department of Ophthalmology & Vision Science, University of California Davis Eye Center, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Christian Dolf
- Department of Ophthalmology & Vision Science, University of California Davis Eye Center, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Yanhong Ma
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, 116024, China
| | - Guozhen Wang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, 116024, China
| | - Jessicca Cho
- UC Davis EyePod Small Animals Ocular Imaging Laboratory, University of California Davis, Davis, CA 95616, USA
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
| | - Nicholas Marsh-Armstrong
- Department of Ophthalmology & Vision Science, University of California Davis Eye Center, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Robert J Zawadzki
- UC Davis EyePod Small Animals Ocular Imaging Laboratory, University of California Davis, Davis, CA 95616, USA
- Center for Human Ocular Imaging Research (CHOIR), Dept. of Ophthalmology & Vision Science, University of California Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
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Wong CSM, Hung IFN, Kwan MYW, Chung MMH, Chan MWM, Cheng AKC, Lau YM, Yeung CK, Chan HHL, Lau CS. Cutaneous manifestations, viral load, and prognosis among hospitalised patients with COVID-19: a cohort study. Hong Kong Med J 2023; 29:421-431. [PMID: 37853787 DOI: 10.12809/hkmj2210199] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023] Open
Abstract
INTRODUCTION Various cutaneous manifestations have been reported as symptoms of coronavirus disease 2019 (COVID-19), which may facilitate early clinical diagnosis and management. This study explored the incidence of cutaneous manifestations among hospitalised patients with COVID-19 and investigated its relationships with viral load, co-morbidities, and outcomes. METHODS This retrospective study included adult patients admitted to a tertiary hospital for COVID-19 from July to September 2020. Clinical information, co-morbidities, viral load (cycle threshold [Ct] value), and outcomes were analysed. RESULTS In total, 219 patients with confirmed COVID-19 were included. Twenty patients presented with new onset of rash. The incidence of new rash was 9.1% (95% confidence interval=6.25%-14.4%). The most common manifestations were maculopapular exanthem (n=6, 42.9%, median Ct value: 24.8), followed by livedo reticularis (n=4, 28.6%, median Ct value: 21.3), varicella-like lesions (n=2, 14.3%, median Ct value: 19.3), urticaria (n=1, 7.1%, median Ct value: 14.4), and acral chilblain and petechiae (n=1, 7.1%, median Ct value: 33.1). The median Ct values for patients with and without rash were 22.9 and 24.1, respectively (P=0.58). There were no significant differences in mortality or hospital stay between patients with and without rash. Patients with rash were more likely to display fever on admission (P<0.01). Regardless of cutaneous manifestations, patients with older age, hypertension, and chronic kidney disease stage ≥3 had significantly higher viral load and mortality (P<0.05). CONCLUSION This study revealed no associations between cutaneous manifestation and viral load or clinical outcomes. Older patients with multiple co-morbidities have risks of high viral load and mortality; they should be closely monitored.
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Affiliation(s)
- C S M Wong
- Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - I F N Hung
- Division of Infectious Diseases, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - M Y W Kwan
- Paediatric Infectious Disease Unit, Department of Paediatrics and Adolescent Medicine, Princess Margaret Hospital, Hong Kong SAR, China
| | - M M H Chung
- Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - M W M Chan
- Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - A K C Cheng
- Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Y M Lau
- Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - C K Yeung
- Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - H H L Chan
- Division of Dermatology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - C S Lau
- Division of Rheumatology and Clinical Immunology, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Lam CHI, Zou B, Chan HHL, Tse DYY. Functional and structural changes in the neuroretina are accompanied by mitochondrial dysfunction in a type 2 diabetic mouse model. Eye Vis (Lond) 2023; 10:37. [PMID: 37653465 PMCID: PMC10472703 DOI: 10.1186/s40662-023-00353-2] [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] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 07/16/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Diabetic retinopathy (DR), one of the leading causes of blindness and vision impairment, is suggested to exhibit functional and structural changes in retinal neurons as the earliest manifestation, which could be used to predict the progression of related angiopathy. While neural function and survival rely on proper mitochondrial function, and a growing body of literature has supported the role of mitochondrial dysfunction in the development of DR, how diabetes affects mitochondrial function in retinal tissue remains elusive. This study primarily aimed to investigate mitochondrial functional changes in a diabetic rodent model. We also characterized the early DR phenotype, in particular, neurodegeneration. METHODS C57BLKsJ-db/db (db/db) mice (a type 2 diabetic mouse model) were used with their normoglycemic heterozygous littermates (db/+) serving as controls. Longitudinal changes in retinal function and morphology were assessed with electroretinography (ERG) and optical coherence tomography (OCT), respectively, at 9, 13, 17, and 25 weeks of age. At 25 weeks, the retinas were harvested for immunohistochemistry and ex vivo mitochondrial bioenergetics. RESULTS Decreased ERG responses were observed in db/db mice as early as 13 weeks of age. OCT revealed that db/db mice had significantly thinner retinas than the controls. Immunohistochemistry showed that the retinas of the db/db mice at 25 weeks were thinner at the outer and inner nuclear layers, with lower photoreceptor and cone cell densities compared with the db/+ mice. The number of rod-bipolar cell dendritic boutons and axon terminals was significantly reduced in db/db mice relative to the db/+ mice, suggesting that diabetes may lead to compromised synaptic connectivity. More importantly, the retinas of db/db mice had weaker mitochondrial functions than the controls. CONCLUSIONS Our longitudinal data suggest that diabetes-induced functional deterioration and morphological changes were accompanied by reduced mitochondrial function in the retina of db/db mice. These findings suggest that mitochondrial dysfunction may be a contributing factor triggering the development of DR. While the underlying mechanistic cause remains elusive, the db/db mice could be a useful animal model for testing potential treatment regimens targeting neurodegeneration in DR.
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Affiliation(s)
- Christie Hang-I Lam
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
- Centre for Eye and Vision Research Limited (CEVR), Hong Kong, SAR, China
| | - Bing Zou
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Henry Ho-Lung Chan
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
- Centre for Eye and Vision Research Limited (CEVR), Hong Kong, SAR, China
| | - Dennis Yan-Yin Tse
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China.
- Centre for Eye and Vision Research Limited (CEVR), Hong Kong, SAR, China.
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, SAR, China.
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Lakshmanan Y, Wong FSY, Chan HHL. Long-Term Effects on Retinal Structure and Function in a Mouse Endothelin-1 Model of Retinal Ganglion Cell Degeneration. Invest Ophthalmol Vis Sci 2023; 64:15. [PMID: 37561449 PMCID: PMC10424801 DOI: 10.1167/iovs.64.11.15] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/22/2023] [Indexed: 08/11/2023] Open
Abstract
Purpose To study the long-term effects of endothelin-1 (ET-1)-induced retinal pathologies in mouse, using clinically relevant tools. Methods Adult C57BL/6 mice (7-9 weeks old) were intravitreally injected with PBS (n = 10) or 0.25 (n = 8), 0.5 (n = 8), or 1 nmol ET-1 (n = 9) and examined using electroretinogram, optical coherence tomography (OCT), and Doppler OCT at baseline and postinjection days 10, 28, and 56. Retinal ganglion cell (RGC) survival in retinal whole mount was quantified at days 28 and 56. Results ET-1 induced immediate retinal arterial constriction. The significantly reduced total blood flow and positive scotopic threshold response in the 0.5- and 1-nmol ET-1 groups at day 10 were recovered at day 28. A-wave magnitude was also significantly reduced at days 10 and 28. While a comparable and significant reduction in retinal nerve fiber layer thickness was detected in all ET-1 groups at day 56, the 1-nmol group was the earliest to develop such change at day 28. All ET-1 groups showed a transient inner retinal layer thinning at days 10 and 28 and a plateaued outer layer thickness at days 10 to 56. The 1-nmol group showed a significant RGC loss over all retinal locations examined at day 28 as compared with PBS control. As for the lower-dosage groups, significant RGC density loss at central and midperipheral retina was detected at day 56 when compared with day 28. Conclusions ET-1 injection in mice resulted in a transient vascular constriction and reduction in retinal functions, as well as a gradual loss of retinal nerve fiber layer and RGC in a dose-dependent manner.
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Affiliation(s)
| | | | - Henry Ho-Lung Chan
- Centre for Eye and Vision Research (CEVR), Hong Kong, Hong Kong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong SAR, China
- University Research Facilities in Behavioral and Systems Neuroscience (UBSN), The Hong Kong Polytechnic University, Hong Kong SAR, China
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Choi KY, Leung TW, Chan HHL. Size of living space as a moderator for central and peripheral refractions in children. Sci Rep 2023; 13:10797. [PMID: 37402825 DOI: 10.1038/s41598-023-37454-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 06/22/2023] [Indexed: 07/06/2023] Open
Abstract
Undesirable living environment may impose risk on myopia development. Furthermore, peripheral refractive error was suggested to contribute to juvenile eye growth modulation. This study aimed to investigate the interaction between peripheral refractive error and living environment in relation to central refractive status in Hong Kong schoolchildren. Central and peripheral refractive errors, axial length (AL), and corneal radius of curvature (CR) were measured in 573 schoolchildren (age 9.5 ± 0.9 years). The AL/CR ratio was used to represent the central refractive status, accounting for non-cycloplegic refraction. The relative peripheral refractive errors (RPRE) up to ± 20° eccentricities were converted into power vectors: spherical-equivalent error (SER) and J0 astigmatic components and fitted with quadratic equations. The second-order coefficients of SER (aSER) and J0 astigmatism (aJ0) and home size reported by parental questionnaires were analyzed to indicate their relationships with AL/CR. Our results showed that children with higher AL/CR lived in smaller homes (p = 0.01) and had a more hyperopic (p < 0.001) but less astigmatic RPRE (p = 0.01). We further analyzed the relationship between AL/CR with RPRE for children living in small (< 300 ft2), moderate (300-600 ft2), and large home sizes (> 600 ft2). Regardless of the home size, a higher AL/CR remained moderately correlated with a more hyperopic aSER (all p < 0.001). However, a higher AL/CR was associated with a more positive aJ0 only in children living in large homes, and the relationships were not significant for small and moderate home sizes. Linear regression models further indicated that home size was a significant moderator contributing to the relationship between AL/CR and aJ0. In conclusion, our results were consistent with previous studies, showing that children with axial myopia usually lived in smaller homes and had more hyperopic defocus and more positive J0 astigmatism. However, the relationship between peripheral astigmatism and axial refraction was modulated by the home size of Hong Kong schoolchildren. While peripheral astigmatism is hypothesized as a visual cue for axial refractive development in children, extrinsic environmental factors, such as home size, might interfere with the relationship and dominate refractive development.
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Affiliation(s)
- Kai Yip Choi
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Kowloon, Hong Kong
| | - Tsz Wing Leung
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Kowloon, Hong Kong
- Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Pak Shek Kok, Shatin, Hong Kong
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Kowloon, Hong Kong
| | - Henry Ho-Lung Chan
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Kowloon, Hong Kong.
- Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Pak Shek Kok, Shatin, Hong Kong.
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Kowloon, Hong Kong.
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Choi KY, Chan HHL. Near work, light levels and dioptric profile - Which factor dominates and influences the short-term changes in axial length? Ophthalmic Physiol Opt 2023. [PMID: 37133243 DOI: 10.1111/opo.13153] [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: 02/14/2023] [Accepted: 04/11/2023] [Indexed: 05/04/2023]
Affiliation(s)
- Kai Yip Choi
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Henry Ho-Lung Chan
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
- Research Centre for SHARP Vision, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
- Centre for Eye and Vision Research, Pak Shek Kok, Hong Kong
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Vyas SA, Lakshmanan Y, Chan HHL, Leung TW, Kee CS. Experimentally induced myopia and myopic astigmatism alter retinal electrophysiology in chickens. Sci Rep 2022; 12:21180. [PMID: 36477183 PMCID: PMC9729572 DOI: 10.1038/s41598-022-25075-8] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 11/24/2022] [Indexed: 12/12/2022] Open
Abstract
Myopia (or "short-sightedness") and astigmatism are major causes of visual impairment worldwide. Significant amounts of astigmatism are frequently observed in infants and have been associated with myopia development. Although it is well established that both myopia and astigmatism are associated with ocular structural changes from anterior to posterior segments, very little is known on how these refractive errors alter retinal functions. This study investigated the effects of experimentally induced myopia and myopic-astigmatism on retinal electrophysiology by using an image-guided, multifocal global flash stimulation in chickens, a widely used animal model for refractive error development. Myopia and myopic-astigmatism were experimentally induced, respectively, by wearing spherical (- 10 D, n = 12) and sphero-cylindrical lenses (- 6.00 DS/- 8.00 DCx90: Hyperopic With-The Rule, H-WTR, n = 15; - 6.00 DS/- 8.00 DCx180: Hyperopic Against-The-Rule, H-ATR, n = 11) monocularly for a week (post-hatching day 5 to 12). An aged-matched control group without any lens treatment provided normal data (n = 12). Multifocal electrophysiological results revealed significant regional variation in the amplitude of induced component (IC) (central greater than peripheral; both p < 0.05) in the normal and H-ATR groups, but not in the - 10 D and H-WTR groups. Most importantly, for the first time, our results showed that both H-WTR and H-ATR groups exhibited a significantly longer implicit time of the inner retinal response at the central region when compared to the normal and - 10 D groups, highlighting a significant role of astigmatism in retinal physiology.
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Affiliation(s)
- Sonal Aswin Vyas
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Yamunadevi Lakshmanan
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China.,Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Henry Ho-Lung Chan
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China.,Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China.,Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong, China
| | - Tsz-Wing Leung
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China.,Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong, China.,Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Chea-Su Kee
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China. .,Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong, China. .,Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Kowloon, Hong Kong.
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Lai JSM, Chan HHL, Chan JCH, Lo ACY, Lee JWY, Chang RCC, So KF. Neuroprotective effects of wolfberry in normal tension glaucoma: abridged secondary publication. Hong Kong Med J 2022; 28 Suppl 1:46-47. [PMID: 35260518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023] Open
Affiliation(s)
- J S M Lai
- Department of Ophthalmology, The University of Hong Kong
| | - H H L Chan
- Department of Ophthalmology, The University of Hong Kong
| | - J C H Chan
- Department of Ophthalmology, The University of Hong Kong
| | - A C Y Lo
- Department of Ophthalmology, The University of Hong Kong
| | - J W Y Lee
- Department of Ophthalmology, The University of Hong Kong
| | - R C C Chang
- Department of Ophthalmology, The University of Hong Kong
| | - K F So
- Department of Ophthalmology, The University of Hong Kong
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Choi KY, Chan HHL. Extrinsic and Intrinsic Factors Regulating Juvenile Refractive Development and Eye Growth. Invest Ophthalmol Vis Sci 2021; 62:21. [PMID: 34797905 PMCID: PMC8606828 DOI: 10.1167/iovs.62.14.21] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose Peripheral refraction and accommodation are intrinsic factors that were once hypothesized to trigger myopia but are now controversial. Previously, home nearwork environment (i.e., extrinsic factor) was reported to be associated with myopia progression. In this study, we aimed to evaluate the potential interaction between extrinsic and intrinsic factors with juvenile refractive development. Methods Nearwork environmental parameters were measured for 50 children (aged 9.3 ± 1.2 years), including net amount and dispersion of defocus. Refraction was measured at near distances and in central field (±30° horizontal) at 3m. The relative peripheral refraction (RPRE) was obtained and presented in a vectoral approach. The linear regression coefficient was extracted (mAcc) from the accommodative stimulus-response curve. RPRE was quadratically regressed against field eccentricity, and the first coefficients (aM, aJ0, aP90, and aP180) were extracted. Relationships between RPRE, baseline accommodation, and 1-year myopia progression (∆M), controlled for the nearwork environment, were evaluated. Results Coefficients of RPRE were independent of ∆M. However, additional nearwork environmental parameters significantly improved the variance in ∆M explained by aM and aP180 (P < 0.03). The relationship between intrinsic factor and ∆M was stronger when the extrinsic risk was low (P ≤ 0.01), whereas the relationship was abolished when extrinsic risk was high. For mAcc, it also significantly improved the variance in ∆M explained by nearwork environmental parameters. Conclusions The interaction between extrinsic (environment) and intrinsic (RPRE and accommodation) factors is speculated to contribute to juvenile myopia progression. Our findings may also explain the inconsistencies of such intrinsic factors in the literature.
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Affiliation(s)
- Kai Yip Choi
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Henry Ho-Lung Chan
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong.,Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong.,Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong
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Abstract
Myopia, the most common refractive error, is estimated to affect over two billion people worldwide, especially children from East Asian regions. Children with early onset myopia have an increased risk of developing sight threatening complications in later life. In addition to the contribution of genetic factors, of which expression is controversially suggested to be subject to environmental regulation, various environmental factors, such as near-work, outdoor, and living environment, have also been determined to play significant roles in the development of refractive error, especially juvenile myopia. Cues from daily visual scenes, including lighting, spatial frequency, and optical defocus over the field of visual stimuli, are suggested to influence emmetropisation, thereby affecting myopia development and progression. These risk factors in visual scenes of the everyday life may explain the relationship between urbanicity and myopia prevalence. This review first summarises the previously reported associations between myopia development and everyday-life environments, including schooling, urban settings, and outdoors. Then, there is a discussion of the mechanisms hypothesised in the literature about the cues from different visual scenes of urbanicity in relation to myopia development.
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Affiliation(s)
- Kai Yip Choi
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Sonia Seen-Hang Chan
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Henry Ho-Lung Chan
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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Abstract
The first-order kernel analysis in multifocal electroretinogram (mfERG) using low contrast stimulation is suggested as a way to detect the inner retinal responses in animal studies. In this case report, this protocol is applied to human patients with glaucoma to demonstrate the possibility of using mfERG as a tool to detect glaucomatous damage. Two patients with glaucoma were recruited and had mfERG measurements with the 103-scaled hexagonal stimulus pattern at low (50 per cent) contrast. Their responses were analysed and compared with those from normal subjects with the mfERG measured under the same condition. In the normal subjects, there were obvious oscillatory components on the ascending and descending limbs of the first-order kernel response to 50 per cent contrast. In the glaucomatous patients, the oscillatory component on the descending limb was obviously diminished. In addition, this component was significantly diminished in the quadrant with a glaucomatous visual field defect. This suggests that the low-contrast stimulation condition in mfERG measurement may provide a good way to detect glaucomatous damage and this may help in clinical diagnosis of glaucoma.
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Affiliation(s)
- Henry Ho-Lung Chan
- School of Optometry, Hong Kong Polytechnic University, Hong Kong SAR, China.
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Lakshmanan Y, Wong FSY, Zuo B, Bui BV, Chan HHL. Longitudinal outcomes of circumlimbal suture model-induced chronic ocular hypertension in Sprague-Dawley albino rats. Graefes Arch Clin Exp Ophthalmol 2020; 258:2715-2728. [PMID: 32623578 DOI: 10.1007/s00417-020-04820-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 01/29/2020] [Revised: 06/03/2020] [Accepted: 06/26/2020] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To characterise longitudinal structural and functional changes in albino Sprague-Dawley rats following circumlimbal suture ocular hypertension (OHT) induction. METHODS Ten-week-old rats (n = 24) underwent suture implantation around the limbal region in both eyes. On the next day, the suture was removed from one eye (control eyes) and left intact in the other eye (OHT eyes) of each animal. Intraocular pressure (IOP) was monitored weekly twice for the next 15 weeks. Optical coherence tomography (OCT) and electroretinogram (ERG) were measured at baseline and weeks 4, 8, 12, and 15, and eyes were then collected for histological assessment. RESULTS Sutured eyes (n = 12) developed IOP elevation of ~ 50% in the first 2 weeks that was sustained at ~ 25% above the control eye up to week 15 (p = 0.001). Animals with insufficient IOP elevation (n = 6), corneal changes (n = 3), and attrition (n = 3) were excluded from the analysis. OHT eyes developed significant retinal nerve fibre layer (RNFL) thinning (week 4: - 19 ± 14%, p = 0.10; week 8: - 17 ± 12%, p = 0.04; week 12: - 16 ± 10%, p = 0.04, relative to baseline) and reduction in retinal ganglion cell (RGC) density (- 32 ± 26%, p = 0.02). At week 15, both inner (9 ± 7%, p = 0.01) and outer retinal layer thicknesses (6.0 ± 5%, p = 0.001) showed a mild increase in thicknesses. The positive scotopic threshold response (- 28 ± 25%, p = 0.04) and a-wave were significantly reduced at week 12 (- 35 ± 21%; p = 0.04), whereas b-wave was not significantly affected (week 12: - 18 ± 27%, p = 0.24). CONCLUSION The circumlimbal suture model produced a chronic, moderate IOP elevation in an albino strain that led to RNFL thinning and reduced RGC density along with the reductions in ganglion and photoreceptoral cell functions. There was a small thickening in both outer and inner retinal layers.
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Affiliation(s)
- Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Francisca Siu Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Bing Zuo
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Bang Viet Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Australia
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China. .,Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.
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Choi KY, Mok AYT, Do CW, Lee PH, Chan HHL. The diversified defocus profile of the near-work environment and myopia development. Ophthalmic Physiol Opt 2020; 40:463-471. [PMID: 32519412 PMCID: PMC7497190 DOI: 10.1111/opo.12698] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 01/31/2020] [Accepted: 05/04/2020] [Indexed: 12/16/2022]
Abstract
Purpose To quantify the defocus characteristics in the near‐work environment at home and investigate the relationship with subsequent myopia progression. Methods Fifty subjects (aged 7–12 years) were recruited and followed for 1 year. The home near‐work environment (writing desk) was measured at a baseline home‐visit using the Kinect‐for‐Windows to capture a 3‐dimensional image. The depth values of the image were then converted into scene defocus with respect to the subject’s viewpoint. The defocus characteristics were quantified as the dioptric volume (the total amount of net defocus, or DV) and standard deviation of the defocus values (SDD). Information on home size, time spent outdoors, and in front of a desk were also obtained. Univariate correlation, and multivariate regression were used to assess the association between myopia progression, defocus characteristics, and other co‐variates. Results The baseline spherical equivalent refraction (M) and refraction change over 1 year (∆M) were − 1.51 ± 2.02 D and − 0.56 ± 0.45 D respectively. DV was not significantly correlated with ∆M (Spearman’s ρ = −0.25, p = 0.08), while SDD was negatively correlated to ∆M (Spearman’s ρ = −0.42, p = 0.003). Although SDD was not a significant predictor in multivariate analysis, the regional DV at 15°–20° eccentricity was significant (p = 0.001). Home size (F2,50 = 7.01, p = 0.002) and time spent outdoors (Independent t = −2.13, p = 0.04) were also associated with ∆M, but not time spent in front of desk (Independent t = 0.78, p = 0.44). Conclusion The defocus profile in the home environment within the para‐central field of view is associated with childhood refractive error development.
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Affiliation(s)
- Kai Yip Choi
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Angela Yuen-Ting Mok
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Chi-Wai Do
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Paul Hong Lee
- School of Nursing, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Henry Ho-Lung Chan
- The Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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Lakshmanan Y, Wong FSY, Zuo B, So KF, Bui BV, Chan HHL. Posttreatment Intervention With Lycium Barbarum Polysaccharides is Neuroprotective in a Rat Model of Chronic Ocular Hypertension. Invest Ophthalmol Vis Sci 2020; 60:4606-4618. [PMID: 31756254 DOI: 10.1167/iovs.19-27886] [Citation(s) in RCA: 15] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the neuroprotective effects of Lycium barbarum polysaccharides (LBP) against chronic ocular hypertension (OHT) in rats and to consider if effects differed when treatment was applied before (pretreatment) or during (posttreatment) chronic IOP elevation. Methods Sprague-Dawley rats (10-weeks old) underwent suture implantation around the limbus for 15 weeks (OHT) or 1 day (sham). Four experimental groups were studied, three OHT groups (n = 8 each) treated either with vehicle (PBS), LBP pretreatment or posttreatment, and a sham control (n = 5) received no treatment. LBP (1 mg/kg) pre- and posttreatment were commenced at 1 week before and 4 weeks after OHT induction, respectively. Treatments continued up through week 15. IOP was monitored twice weekly for 15 weeks. Optical coherence tomography and ERG were measured at baseline, week 4, 8, 12, and 15. Eyes were collected for ganglion cell layer (GCL) histologic analysis at week 15. Results Suture implantation successfully induced approximately 50% IOP elevation and the cumulative IOP was similar between the three OHT groups. When compared with vehicle control (week 4: -23 ± 5%, P = 0.03), LBP pretreatment delayed the onset of retinal nerve fiber layer (RNFL) thinning (week 4, 8: -2 ± 7%, -11 ± 3%, P > 0.05) and arrested further reduction up through week 15 (-10 ± 4%, P > 0.05). LBP posttreatment intervention showed no significant change in rate of loss (week 4, 15: -25 ± 4.1%, -28 ± 3%). However, both LBP treatments preserved the retinal ganglion cells (RGC) and retinal functions up to week 15, which were significantly reduced in vehicle control. Conclusions LBP posttreatment arrested the subsequent neuronal degeneration after treatment commencement and preserved RGC density and retinal functions in a chronic OHT model, which was comparable with pretreatment outcomes.
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Affiliation(s)
- Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Francisca Siu Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Bing Zuo
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Kwok-Fai So
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.,Guangdong-Hongkong-Macau (GHM) Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Bang Viet Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Australia
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.,Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
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Tse JSH, Lam TC, Cheung JKW, Sze YH, Wong TK, Chan HHL. Data on assessment of safety and tear proteome change in response to orthokeratology lens - Insight from integrating clinical data and next generation proteomics. Data Brief 2020; 29:105186. [PMID: 32071970 PMCID: PMC7013139 DOI: 10.1016/j.dib.2020.105186] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/18/2020] [Accepted: 01/21/2020] [Indexed: 11/29/2022] Open
Abstract
Breath-O™ Correct Ortho-K lenses are newly designed ortho-K lenses which are made from a silicon and fluoride containing methacrylate compound. This compound is said to be more flexible, durable and less likely to break compared to traditional Ortho-K lenses. The special design of this Ortho-K lens can reshape the corneal profile to induce temporary myopic reduction while producing beneficial peripheral hyperopic defocus for myopia control. To evaluate the safety and ocular surface responses of overnight Ortho-K wear over 1 and 3 months using this new type of material, we evaluated the clinical parameters (corneal integrity, corneal biomechanics, corneal endothelial health, non-invasive keratographical break-up time) and profiled the change of global tear proteome on healthy young subjects using next generation proteomics (SWATH-MS). The acquired mass spectrometric data were processed and analyzed using a cloud based Oneomics™ bioinformatic platform. All raw data generated from Information-dependent acquisition (IDA) and SWATH acquisitions were accepted and published in the Peptide Atlas public repository for general release (http://www.peptideatlas.org/PASS/PASS01367).
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Lakshmanan Y, Wong FSY, Yu WY, Li SZC, Choi KY, So KF, Chan HHL. Lycium Barbarum Polysaccharides Rescue Neurodegeneration in an Acute Ocular Hypertension Rat Model Under Pre- and Posttreatment Conditions. Invest Ophthalmol Vis Sci 2019; 60:2023-2033. [PMID: 31067322 DOI: 10.1167/iovs.19-26752] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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 investigate the posttreatment neuronal rescue effects of Lycium barbarum polysaccharides (LBP) in an acute ocular hypertensive (AOH) model. Methods Intraocular pressure (IOP) was elevated manometrically to 80 mm Hg (AOH) or 15 mm Hg (sham) for 120 minutes in adult Sprague-Dawley rats. Five experimental groups were considered: Three AOH groups were pretreated with PBS (vehicle) (n = 9), LBP 1 mg/kg (n = 8), or 10 mg/kg (n = 13), and one AOH group was posttreated with LBP 10 mg/kg (n = 8), once daily. The sham cannulation group (n = 5) received no treatment. Pretreatments commenced 7 days before and posttreatment 6 hours after AOH, and continued up through postcannulation day 28. All the animals underwent optical coherence tomography and electroretinogram measurements at baseline and postcannulation days 10 and 28. The ganglion cell layer (GCL) densities were quantified at day 28. Results Both inner retinal layer thickness (IRLT) and positive scotopic threshold response (pSTR) underwent significant reduction (≥50% of thickness and amplitude) in the vehicle group (P < 0.05). Pretreatment with LBP 1 and 10 mg/kg retained 77 ± 11% and 89 ± 8% of baseline IRLT, respectively, and preserved pSTR functions. The posttreatment group showed a significant reduction in IRLT (-35 ± 8%, P < 0.001) and pSTR (∼48% of baseline, P < 0.001) on day 10. By day 28, there was an improvement in functional pSTR (∼72% of baseline, P > 0.05) with no significant further thinning (-40 ± 8%, P = 0.15) relative to day 10. GCL density was reduced in vehicle control (P = 0.0001), but did not differ between sham and pre- and posttreated AOH groups. Conclusions The rescue effect of LBP posttreatment was observed later, which arrested the secondary degeneration and improved the retinal function.
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Affiliation(s)
- Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Francisca Siu-Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Wing-Yan Yu
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Serena Zhe-Chuang Li
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Kai-Yip Choi
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Kwok-Fai So
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Guangdong-Hongkong-Macau (GHM) Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
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Chan HHL, Lam HI, Choi KY, Li SZC, Lakshmanan Y, Yu WY, Chang RCC, Lai JSM, So KF. Delay of cone degeneration in retinitis pigmentosa using a 12-month treatment with Lycium barbarum supplement. J Ethnopharmacol 2019; 236:336-344. [PMID: 30877066 DOI: 10.1016/j.jep.2019.03.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [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: 08/24/2018] [Revised: 03/06/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Lycium barbarum L. (also known as "Goji berry"), a traditional Chinese herbal medicine, has been a common herb in the traditional Chinese pharmacopoeia for centuries. The main active component is the Lycium barbarum polysaccharides and its antioxidative effect has been widely shown to provide neuroprotection to the eye, and it would, therefore, be interesting to determine if Lycium barbarum help delay vision deterioration in patients with retinitis pigmentosa. AIM OF THE STUDY Cone rescue is a potential method for delaying deterioration of visual function in Retinitis pigmentosa (RP). This study aimed to investigate the treatment effect of Lycium barbarum L. (LB) supplement on retinal functions and structure in RP patients after a 12-month intervention trial. METHODS The investigation was a double-masked and placebo-controlled clinical study. Each of forty-two RP subjects who completed the 12-month intervention (23 and 19 in the treatment and placebo groups respectively) received a daily supply of LB or placebo granules for oral administration. The primary outcome was change of best corrected visual acuity (VA) (90% and 10% contrast) from the baseline to the end of treatment. The secondary outcomes were sensitivity changes of the central visual field, amplitude of full-field electroretinogram (ffERG) (including scotopic maximal response and photopic cone response), and average macular thickness. RESULTS The compliance rates for both groups exceeded 80%. There were no deteriorations of either 90% or 10% contrast VA in the LB group compared with the placebo group (p = 0.001). A thinning of macular layer was observed in the placebo group, which was not observed in the LB group (p = 0.008). However, no significant differences were found in the sensitivity of visual field or in any parameters of ffERG between the two groups. No significant adverse effects were reported in the treatment group. CONCLUSIONS LB supplement provides a neuroprotective effect for the retina and could help delay or minimize cone degeneration in RP. CLASSIFICATIONS Clinical Studies (1.05). TRIAL REGISTRATION clinicaltrials.gov Identifier NCT02244996.
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Affiliation(s)
- Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.
| | - Hang-I Lam
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Kai-Yip Choi
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Serena Zhe-Chuang Li
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Wing-Yan Yu
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Raymond Chuen-Chung Chang
- Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Jimmy Shiu-Ming Lai
- Department of Ophthalmology, The University of Hong Kong, Hong Kong SAR, China
| | - Kwok-Fai So
- Department of Ophthalmology, The University of Hong Kong, Hong Kong SAR, China; Guangdong-Hongkong-Macau (GHM) Institute of CNS Regeneration, Jinan University, Guangzhou, China
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Leung KY, Chan HHL, Leung MP. Subjective and objective evaluation of visual functions in dyslexic children with visual perceptual deficiency-Before and after ten-weeks of perceptual training. Res Dev Disabil 2018; 80:112-130. [PMID: 30015270 DOI: 10.1016/j.ridd.2018.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [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: 04/13/2017] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 06/08/2023]
Abstract
AIMS This pilot study investigated perceptual and electrophysiological characteristics of dyslexic children, and evaluated the immediate and prolonged effect of visual perceptual training on these characteristics in these children. METHODS AND PROCEDURES Seven dyslexic children and seven controls aged 7-8 years were recruited and completed this study. All dyslexic children completed 10-weeks of visual perceptual training. The visual perceptual skills were assessed and binocular visual evoked potentials (VEP) were recorded with two different pattern stimulations initially (Baseline), 3 months after the first assessment (Evaluation I) and 6 months after first assessment (Evaluation II). OUTCOMES AND RESULTS A significant reduction (p = 0.021) in VEP amplitudes in the dyslexic subjects in response to 15 Hz reversal frequency at 15% contrast stimulation was found, compared with controls, prior to perceptual training. A significant correlation (p = 0.005) was found between the VEP amplitude with 15 Hz reversal frequency and the total score of Test of Visual Perceptual Skills (non-motor) - revised (TVPS-R). After training, dyslexic subjects scored higher in some of the visual perceptual tasks and these improvements persisted for 3 months. However, the VEP amplitude in the dyslexics showed no significant change after perceptual training.
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Affiliation(s)
- Ka-Yan Leung
- School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region.
| | - Henry Ho-Lung Chan
- School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
| | - Mei-Po Leung
- School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region
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Li SZC, Yu WY, Choi KY, Lam CHI, Lakshmanan Y, Wong FSY, Chan HHL. Subclinical Decrease in Central Inner Retinal Activity Is Associated With Myopia Development in Children. Invest Ophthalmol Vis Sci 2017; 58:4399–4406. [PMID: 28813575 DOI: 10.1167/iovs.16-21279] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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 investigate the characteristics of retinal electrophysiological activity in relation to early myopia development in children. Methods Fifty-six children aged 6 to 9 years with emmetropic refractive error (defined as ≥ -0.5 diopter [D] and ≤ +0.5 D) were recruited. Cycloplegic refraction, axial length, and global flash multifocal electroretinogram (MOFO mfERG) at 49% and 96% contrast levels were recorded in all children at their first visit. The refraction and axial length measurements were repeated after 1 year. The amplitudes and implicit times of the direct component (DC) and the induced component (IC) of the MOFO mfERG obtained at the initial visit were analyzed. Correlations between the MOFO mfERG parameters and changes in refractive error and axial length were investigated. Results The mean spherical equivalent refractive error and axial length of the eyes of the children at the first visit were +0.19 ± 0.33 D and 23.14 ± 0.6 mm, respectively. After 1 year, the mean refractive error increased by -0.55 ± 0.53 D, whereas axial length increased by 0.37 ± 0.22 mm. The changes in refractive error and axial length were significantly correlated with the central IC amplitudes at 49% contrast level measured at the initial visit (ρ = 0.46, P < 0.001 and ρ = -0.34, P = 0.01, respectively). Conclusions The prospective changes we have shown are believed to derive from central inner retina. These changes appear to precede myopia and could be a potential reference for juvenile myopia development.
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Affiliation(s)
- Serena Zhe-Chuang Li
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
| | - Wing-Yan Yu
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
| | - Kai-Yip Choi
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
| | - Christie Hang-I Lam
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
| | - Yamunadevi Lakshmanan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
| | - Francisca Siu-Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region
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Ho SGY, Chan NPY, Yeung CK, Shek SY, Kono T, Chan HHL. A retrospective analysis of the management of freckles and lentigines using four different pigment lasers on Asian skin. J COSMET LASER THER 2012; 14:74-80. [PMID: 22372516 DOI: 10.3109/14764172.2012.670707] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The risk of post-inflammatory hyperpigmentation (PIH) is increased during freckles and lentigines treatment in Asians. OBJECTIVE To determine the effectiveness and safety of using 595-nm long pulsed dye laser (LPDL), 755-nm LP Alexandrite laser, 532-nm QS Nd:YAG laser and 532-nm LP potassium-titanyl-phosphate (KTP) laser for the treatment of freckles or lentigines in Asian patients. METHODS This is a retrospective study of 40 Chinese patients, who were divided into four groups based on treatment modality using four different pigment lasers. Each patient attended between 1 and 4 treatments (mean of 1.8), at 4-6 weeks intervals, depending on clinical response. Lesional clearance and PIH were assessed by two independent clinicians. RESULTS Statistically significant improvement of global and focal facial pigmentation was found after treatment with LPDL, QS Nd:YAG and LP KTP lasers. No significant improvement was found after LP Alexandrite laser. PIH risk was 20% after LP Alexandrite treatment, 10% with QS Nd:YAG, and absent after LPDL and LP KTP treatment. CONCLUSION A long pulse laser and small spot size appear to reduce the risks of lentigines treatment in darker skin types.
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Affiliation(s)
- S G Y Ho
- Division of Dermatology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Abstract
PURPOSE To study the changes in retinal electrophysiology in children during myopia progression during a 1-year period. METHODS Twenty-six children aged from 9 to 13 years were recruited for the global flash multifocal electroretinogram (mfERG) measured at 49% and 96% contrast, in two visits 1 year apart. The amplitudes and implicit times of both direct component (DC) and induced component (IC) measured at these two visits were analyzed and compared. Pearson's correlation was used to study the association between the changes of mfERG response and myopia progression during the test period. RESULTS Myopia increased by -0.48 ± 0.32 diopter (D) (P < 0.001) during the year, with 24 of 26 children becoming more myopic (range = 0.00 to ∼ -1.38 D); axial length increased by 0.25 ± 0.11 mm (P < 0.001) during the year. The increased myopia was highly correlated with increase in axial length (r = -0.70; P < 0.001). The central DC and IC amplitudes at 49% contrast reduced significantly as myopia progressed and the paracentral implicit times of these two components were reduced considerably. However, the high-contrast responses were virtually unaffected. CONCLUSIONS Our findings suggested that the inner retinal functions in the central retina, with some involvement of the paracentral region, were decreased as myopia progressed in children.
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Affiliation(s)
- Wing-Cheung Ho
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR
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Lung JCY, Swann PG, Wong DSH, Chan HHL. Global flash multifocal electroretinogram: early detection of local functional changes and its correlations with optical coherence tomography and visual field tests in diabetic eyes. Doc Ophthalmol 2012; 125:123-35. [PMID: 22828871 DOI: 10.1007/s10633-012-9343-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 07/03/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE To investigate the correlations of the global flash multifocal electroretinogram (MOFO mfERG) with common clinical visual assessments--Humphrey perimetry and Stratus circumpapillary retinal nerve fiber layer (RNFL) thickness measurement in type II diabetic patients. METHODS Forty-two diabetic patients participated in the study: Ten were free from diabetic retinopathy (DR), while the remainder suffered from mild to moderate nonproliferative diabetic retinopathy. Fourteen age-matched controls were recruited for comparison. MOFO mfERG measurements were made under high- and low-contrast conditions. Humphrey central 30-2 perimetry and Stratus OCT circumpapillary RNFL thickness measurements were also performed. Correlations between local values of implicit time and amplitude of the mfERG components [direct component (DC) and induced component (IC)], and perimetric sensitivity and RNFL thickness were evaluated by mapping the localized responses for the three subject groups. RESULTS MOFO mfERG was superior to perimetry and RNFL assessments in showing differences between the diabetic groups (with and without DR) and the controls. All the MOFO mfERG amplitudes (except IC amplitude at high contrast) correlated better with perimetry findings (Pearson's r ranged from 0.23 to 0.36, p < 0.01) than did the mfERG implicit time at both high and low contrasts across all subject groups. No consistent correlation was found between the mfERG and RNFL assessments for any group or contrast conditions. The responses of the local MOFO mfERG correlated with local perimetric sensitivity but not with RNFL thickness. CONCLUSION Early functional changes in the diabetic retina seem to occur before morphological changes in the RNFL.
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Affiliation(s)
- J C Y Lung
- Laboratory of Experimental Optometry Neuroscience, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China
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25
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Ho WC, Kee CS, Chan HHL. Myopic children have central reduction in high contrast multifocal ERG response, while adults have paracentral reduction in low contrast response. Invest Ophthalmol Vis Sci 2012; 53:3695-702. [PMID: 22570348 DOI: 10.1167/iovs.11-9379] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [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 retinal function of myopic children and young adults using the multifocal electroretinogram (mfERG). METHODS Fifty-two children (aged 9-14 years) and 19 young adults (aged 21-28 years) with spherical equivalent refractive errors ranging from plano to -5.50 diopter (D) were recruited. They were examined using the global flash mfERG at 49% and 96% contrasts. Each local mfERG response was pooled into five concentric rings for analysis. The amplitudes and implicit times of direct components (DC) and induced components (IC) from the global flash response were analyzed. Hierarchical multiple regressions were used to evaluate the influence of refractive error and axial length on the DC and IC responses. RESULTS Compared with the emmetropes of the same age group, myopic children had a significant reduction in central macular DC response at 96% contrast while the IC response was unaffected, but myopic adults showed significant reductions in paracentral IC amplitudes at 49% contrast. Implicit times for DC and IC responses were unaffected for either group. CONCLUSIONS Retinal function was unaffected in myopic children, except for the outer retina in the central macular region. In contrast, the inner retinal function was substantially reduced in myopic adults, especially in the paracentral region. This study provides further evidence for different retinal, physiological characteristics in myopic children and myopic adults.
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Affiliation(s)
- Wing-Cheung Ho
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region, The People's Republic of China
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Ho WC, Wong OY, Chan YC, Wong SW, Kee CS, Chan HHL. Sign-dependent changes in retinal electrical activity with positive and negative defocus in the human eye. Vision Res 2011; 52:47-53. [PMID: 22100834 DOI: 10.1016/j.visres.2011.10.017] [Citation(s) in RCA: 33] [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: 07/14/2011] [Revised: 10/12/2011] [Accepted: 10/22/2011] [Indexed: 12/13/2022]
Abstract
The purpose of this study was to investigate the effect of optical defocus on changes of electrical response as a function of retinal region. Twenty-three subjects (aged 19-25 year) with normal ocular health were recruited for global flash multifocal electroretinogram (mfERG) recordings under control (fully corrected) condition, and short-term positive defocus (+2D and +4D) and negative defocus (-2D and -4D) conditions. The amplitudes and implicit times of direct (DC) and induced (IC) components of mfERG responses were pooled into six concentric rings for analyses. The mfERG responses demonstrated more significant changes in amplitude in paracentral retinal regions than in the central regions under defocused conditions. The paracentral DC amplitude showed a significant reduction under negative defocus conditions. In contrast, the paracentral IC amplitude showed a significant increment under positive defocus conditions. Interestingly, the central IC response showed significant reduction in amplitude only to negative defocus, while increasing its amplitude to positive defocus. However, the DC and IC implicit times were virtually unaffected under defocused conditions. Our findings suggest that human retina is able to differentiate defocused signals and to identify positive and negative defocus. It shows that paracentral retina reacts more vigorously to optical defocus than does central retina.
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Affiliation(s)
- Wing-Cheung Ho
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
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Chan HHL. Is the peripheral retina an important site for myopic development? [Liu Y, Wildsoet C (2011) The effectof two-zone concentric bifocal spectacle lenses on refractive error development and eye growth in young chicks. Invest Ophthalmol Vis Sci 52(2):1078-1086]. Graefes Arch Clin Exp Ophthalmol 2011; 249:955-6. [PMID: 21643721 DOI: 10.1007/s00417-011-1720-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 05/26/2011] [Accepted: 05/26/2011] [Indexed: 11/28/2022] Open
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Lung JCY, Chan HHL. The Antagonistic Interaction of Cones in Human Eyes—a Pilot Study. Iperception 2011. [PMCID: PMC5393820 DOI: 10.1068/ic302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Multifocal electroretinogram (mfERG) by Sutter (1992) provides a measuring tool of the retinal responses at different locations. Traditional mfERG stimulus at each base period is a pseudorandom m-sequence focal flash. By interleaving seven dark frames between the focal flashes, a slow-sequence stimulus can be formed to trigger retinal responses which are originated predominantly from the bipolar cells and inner retinal cells. In this study, the antagonistic interaction of cones in human eye was investigated by this slow-flash mfERG (sfmfERG) under different colour stimuli (white and blue colour conditions). The N1, P1 and photopic negative response (PhNR) of the sfmfERG were used to investigate the effect on the local retinal responses. It was found that the blue stimulus could trigger greater amplitudes of the N1, P1 and PhNR than the white stimulus did. In terms of the implicit time, the white stimulus would trigger P1 and PhNR with longer implicit time than the blue stimulus. White stimulus provides a broader spectrum signal than blue stimulus. The changes of cone responses from a broad to narrow spectrum stimulation may illustrate a decrease in the involvement of retinal antagonism and thus leads to an increase in amplitude and a decrease in implicit time.
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Ho SGY, Yeung CK, Chan NPY, Shek SY, Chan HHL. A comparison of Q-switched and long-pulsed alexandrite laser for the treatment of freckles and lentigines in oriental patients. Lasers Surg Med 2011; 43:108-13. [PMID: 21384391 DOI: 10.1002/lsm.21045] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Q-switched (QS) lasers are effective in the treatment of freckles and lentigines in Type I and II skin, with minimal adverse effects. Long pulsed (LP) lasers have been proposed to be more suitable for treatment of darker skin types. OBJECTIVES To investigate the efficacy and adverse effects of using QS or LP Alexandrite laser for the treatment of freckles and lentigines in Oriental patients. METHODS A prospective split-face study of 20 Chinese patients who were randomly assigned to undergo a single QS (50 nanosecond) or LP (100 microseconds) laser treatment to either side of their face was carried out. Two blinded physicians assessed clinical efficacy using visual analogue scales of pre- and post-treatment photographs. Subjective assessment was evaluated using questionnaires which detailed the degree of pain, erythema and edema sustained during treatment, and improvement and satisfaction levels at 4, 8, and 12 weeks. RESULTS There was statistically significant improvement in pigmentation (P < 0.05) in both groups throughout the study, with no statistical difference found between the groups. Postinflammatory hyperpigmentation was more frequently found after QS treatment (22%), compared to LP treatment (6%). Majority of patients reported moderate to marked improvement in pigmentation throughout the study with both pulse widths, and correspondingly high levels of satisfaction rates. More severe pain, erythema and edema were experienced during QS Alexandrite treatment. CONCLUSION LP Alexandrite is quick and effective, and carries a lower risk of adverse effects than QS Alexandrite, for the removal of freckles and lentigines in darker skin types.
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Affiliation(s)
- S G Y Ho
- Division of Dermatology, Department of Medicine, The University of Hong Kong, Hong Kong SAR, China
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30
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Chan HHL, Tai KS, Yip LKC. Patient with Leriche's syndrome and concomitant superior mesenteric aneurysm: Evaluation with contrast-enhanced three-dimensional magnetic resonance angiography, computed tomography angiography and digital subtraction angiography. ACTA ACUST UNITED AC 2005; 49:233-7. [PMID: 15932467 DOI: 10.1111/j.1440-1673.2005.01375.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conventional angiography is regarded as the gold standard in vascular imaging but it is invasive, and difficulty may be encountered in the evaluation of aortic occlusion disease. Superior mesenteric artery aneurysm is an uncommon disease, which can result in life-threatening haemorrhage after rupture. With the rapid development of computed tomography angiography (CTA) and magnetic resonance angiography (MRA), high-quality images of the vascular system can be obtained in a non-invasive manner. We report a case of Leriche's syndrome with concomitant superior mesenteric aneurysm using contrast-enhanced 3-D CTA and MRA, with digital subtraction angiography correlation.
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Affiliation(s)
- H H L Chan
- Department of Radiology, Queen Mary Hospital, Hong Kong SAR, China.
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31
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Chan HHL, Kono T. The use of lasers and intense pulsed light sources for the treatment of pigmentary lesions. Skin Therapy Lett 2004; 9:5-7. [PMID: 15550991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Lasers and intense pulsed light sources are frequently used for the treatment of pigmented lesions, and the appropriate selection of devices for different lesions is vital to achieving satisfactory clinical outcomes. In dark-skinned patients, the risk of post-inflammatory hyperpigmentation is of particular importance. In general, long-pulse laser and intense pulsed light sources can be effective with a low risk of post-inflammatory hyperpigmentation (PIH) when used for the treatment of lentigines. However, for dermal pigmentation and tattoo, Q-switched lasers are effective, with a lower risk of complications. In the removal of melanocytic nevi, a combined approach with a long-pulse pigmented laser and a Q-switched laser is particularly applicable.
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Affiliation(s)
- H H L Chan
- Division of Dermatology, Department of Medicine, the University of Hong Kong, China
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32
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Lau CBS, Ho CY, Kim CF, Leung KN, Fung KP, Tse TF, Chan HHL, Chow MSS. Cytotoxic activities of Coriolus versicolor (Yunzhi) extract on human leukemia and lymphoma cells by induction of apoptosis. Life Sci 2004; 75:797-808. [PMID: 15183073 DOI: 10.1016/j.lfs.2004.04.001] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [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: 11/09/2003] [Accepted: 04/02/2004] [Indexed: 01/02/2023]
Abstract
Coriolus versicolor (CV), also known as Yunzhi, is one of the commonly used Chinese medicinal herbs. Although recent studies have demonstrated its antitumour activities on cancer cells in vitro and in vivo, the exact mechanism is not fully elucidated. Hence, the objective of this study was to examine the in vitro cytotoxic activities of a standardized aqueous ethanol extract prepared from Coriolus versicolor on a B-cell lymphoma (Raji) and two human promyelocytic leukemia (HL-60, NB-4) cell lines using a MTT cytotoxicity assay, and to test whether the mechanism involves induction of apoptosis. Cell death ELISA was employed to quantify the nucleosome production resulting from nuclear DNA fragmentation during apoptosis. The present results demonstrated that CV extract at 50 to 800 microg/ml dose-dependently suppressed the proliferation of Raji, NB-4, and HL-60 cells by more than 90% (p < 0.01), with ascending order of IC50 values: HL-60 (147.3 +/- 15.2 microg/ml), Raji (253.8 +/- 60.7 microg/ml) and NB-4 (269.3 +/- 12.4 microg/ml). The extract however did not exert any significant cytotoxic effect on normal liver cell line WRL (IC50 > 800 microg/ml) when compared with a chemotherapeutic anticancer drug, mitomycin C (MMC), confirming the tumour-selective cytotoxicity. Nucleosome productions in HL-60, NB-4 and Raji cells were significantly increased by 3.6-, 3.6- and 5.6-fold respectively upon the treatment of CV extract, while no significant nucleosome production was detected in extract-treated WRL cells. The CV extract was found to selectively and dose-dependently inhibit the proliferation of lymphoma and leukemic cells possibly via an apoptosis-dependent pathway.
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MESH Headings
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- Cell Division/drug effects
- Cell Line, Tumor
- Cell Survival/drug effects
- DNA Fragmentation
- Dose-Response Relationship, Drug
- Drug Screening Assays, Antitumor
- Drugs, Chinese Herbal/pharmacology
- Formazans/metabolism
- Humans
- Leukemia, Promyelocytic, Acute/drug therapy
- Leukemia, Promyelocytic, Acute/metabolism
- Leukemia, Promyelocytic, Acute/pathology
- Liver/drug effects
- Liver/pathology
- Lymphoma, B-Cell/drug therapy
- Lymphoma, B-Cell/metabolism
- Lymphoma, B-Cell/pathology
- Medicine, Chinese Traditional
- Mitomycin/pharmacology
- Nucleosomes/drug effects
- Plants, Medicinal/chemistry
- Tetrazolium Salts/metabolism
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Affiliation(s)
- C B S Lau
- School of Pharmacy, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
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Abstract
Morning glory syndrome is a congenital optic disc anomaly in which much of the excavated colobomatous optic disc is filled with glial tissue. Ocular complications may include strabismus, reduced visual acuity and retinal detachment and it may have systemic associations as in Aicardi's syndrome. A patient with monocular morning glory syndrome and reduced visual acuity is reported. The pattern reversal visually evoked potential was reduced and the latency increased in the affected eye.
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Affiliation(s)
- Rufina Tin-Yan Chan
- Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Kowloon, China
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