1
|
Zhang Y, Bian A, Hang Q, Li L, Zhang S, Cheng G, Zhou Q. Corneal Biomechanical Properties of Various Types of Glaucoma and Their Impact on Measurement of Intraocular Pressure. Ophthalmic Res 2023; 66:749-756. [PMID: 36958304 PMCID: PMC10326840 DOI: 10.1159/000530291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/10/2023] [Indexed: 03/25/2023]
Abstract
INTRODUCTION Corneal biomechanical properties could affect intraocular pressure (IOP) measurement. The aim of this study was to evaluate the differences in corneal biomechanical properties of various types of glaucoma, assess their effect on IOP measurements. METHODS This is an observational clinical study of 486 subjects including 102 normal subjects, 104 ocular hypertension (OHT), 89 normal tension glaucoma (NTG), and 191 high tension glaucoma (HTG). Corneal biomechanical parameters were measured using an ocular response analyzer. The main parameters assessed were corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated pressure measurement (IOPg), and corneal-compensated intraocular pressure (IOPcc). Ultrasound pachymetry was used to measure central corneal thickness (CCT). IOP was measured by a Goldmann applanation tonometer (GAT) and a noncontact tonometer (NCT). Visual field (VF) and refractive status were also recorded. Results were analyzed by one-way analysis of variance, univariate and multivariate linear regression analyses, and Bland-Altman plots. RESULTS Multiple comparison by analysis of variance showed significantly lower CH and CRF in NTG compared to HTG, OHT, and normal subjects (CH: 0.011, 0.015, and 0.033; CRF: 0.001, <0.001, and 0.042, respectively). CRF and CH associated with IOP were measured using either GAT, NCT and IOPcc-GAT, IOPcc-NCT, yet CCT was not. GAT correlated strongly with IOPg (r = 0.79; p < 0.001) and IOPcc (r = 0.77; p < 0.001), but limits of agreement between the measurements were poor. CH and CRF were both negatively correlated with VF change (p < 0.01). CONCLUSION CH and CRF affect the measurement of IOP and were related to types of glaucoma or severity of glaucoma. Pure CCT should not be used to correct IOP values or estimate the risk of disease.
Collapse
Affiliation(s)
- Yang Zhang
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China,
| | - Ailing Bian
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Qijun Hang
- Department of Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Lüe Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Shunhua Zhang
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Gangwei Cheng
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Qi Zhou
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| |
Collapse
|
2
|
Jammal AA, Medeiros FA. Corneal Hysteresis and Rates of Neuroretinal Rim Change in Glaucoma. Ophthalmol Glaucoma 2022; 5:483-489. [PMID: 35331968 PMCID: PMC10278201 DOI: 10.1016/j.ogla.2022.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
PURPOSE To evaluate the impact of corneal hysteresis (CH) as a risk factor for progressive neuroretinal rim loss in glaucoma, as measured by spectral-domain OCT of the Bruch's membrane opening minimum rim width (MRW). DESIGN Prospective, observational cohort study. PARTICIPANTS The study group included 118 eyes of 70 subjects with glaucoma. The average follow-up time for the cohort was 3.9 ± 1.3 years, with an average of 6.4 ± 2.0 spectral-domain OCT tests, ranging from 4 to 12. METHODS Corneal hysteresis measurements were acquired at baseline using the Ocular Response Analyzer (Reichert Instruments). Linear mixed models were used to investigate the relationship between the rates of MRW loss and baseline CH. Multivariable analyses adjusted for other putative predictive factors for progression, including mean intraocular pressure (IOP), central corneal thickness (CCT), age, race, and baseline disease severity. MAIN OUTCOME MEASURES Effects of CH on the rate of MRW change over time. RESULTS Corneal hysteresis had a significant effect on rates of MRW progression over time. Each 1-mmHg lower CH was associated with -0.38 μm/year faster MRW loss (95% confidence interval [CI], -0.70 to -0.06; P = 0.019), after adjustment for other predictive factors. The mean IOP was also significantly associated with progression, with -0.35 μm/year (95% CI, -0.47 to -0.23 μm/year) faster MRW change for each 1-mmHg higher pressure (P < 0.001). In the analysis of predictive strength, the mean IOP was the strongest predictive factor (R2 = 23%), followed by CH (R2 = 14%) and baseline disease severity (R2 = 6%). Central corneal thickness explained only 3% of the variability in slopes of change in global MRW. CONCLUSIONS Lower CH measurements were associated with faster loss of the neuroretinal rim in glaucoma, as measured by MRW. The predictive ability of CH was superior to that of CCT. These findings suggest that CH is an important parameter to be considered in assessing the risk of glaucoma progression.
Collapse
Affiliation(s)
- Alessandro A Jammal
- Vision, Imaging and Performance Laboratory, Duke Eye Center and Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Felipe A Medeiros
- Vision, Imaging and Performance Laboratory, Duke Eye Center and Department of Ophthalmology, Duke University, Durham, North Carolina; Department of Electrical and Computer Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina.
| |
Collapse
|
3
|
Abstract
PURPOSE OF THE REVIEW This review summarizes recent findings on corneal hysteresis, a biomechanical property of the cornea. Corneal hysteresis measurements can be easily acquired clinically and may serve as surrogate markers for biomechanical properties of tissues in the back of the eye, like the lamina cribrosa and peripapillary sclera, which may be related to the susceptibility to glaucomatous damage. RECENT FINDINGS Several studies have provided evidence of the associations between corneal hysteresis and clinically relevant outcomes in glaucoma. Corneal hysteresis has been shown to be predictive of glaucoma development in eyes suspected of having the disease. For eyes already diagnosed with glaucoma, lower corneal hysteresis has been associated with higher risk of progression and faster rates of visual field loss over time. Such associations appear to be stronger than those for corneal thickness, suggesting that corneal hysteresis may be a more important predictive factor. Recent evidence has also shown that cornealcorrected intraocular pressure measurements may present advantages compared to conventional Goldmann tonometry in predicting clinically relevant outcomes in glaucoma. SUMMARY Given the evidence supporting corneal hysteresis as an important risk factor for glaucoma development and its progression, practitioners should consider measuring corneal hysteresis in all patients at risk for glaucoma, as well as in those already diagnosed with the disease.
Collapse
Affiliation(s)
| | - Felipe A Medeiros
- Duke Eye Center and Department of Ophthalmology
- Department of Electrical and Computer Engineering, Pratt School of Engineering, Duke University, Durham, North Carolina, USA
| |
Collapse
|
4
|
Corneal Biomechanical Parameters and Central Corneal Thickness in Glaucoma Patients, Glaucoma Suspects, and a Healthy Population. J Clin Med 2021; 10:jcm10122637. [PMID: 34203884 PMCID: PMC8232810 DOI: 10.3390/jcm10122637] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/01/2021] [Accepted: 06/10/2021] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. METHODS In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. RESULTS The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). CONCLUSION This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group.
Collapse
|
5
|
Corneal hysteresis as a risk factor for optic nerve head surface depression and retinal nerve fiber layer thinning in glaucoma patients. Sci Rep 2021; 11:11677. [PMID: 34083548 PMCID: PMC8175353 DOI: 10.1038/s41598-021-90588-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 05/04/2021] [Indexed: 11/29/2022] Open
Abstract
To evaluate the role of corneal hysteresis (CH) as a risk factor for progressive ONH surface depression and RNFL thinning measured by confocal scanning laser ophthalmoscopy (CSLO) and spectral-domain optical coherence tomography (SD-OCT), respectively in glaucoma patients. Prospective study. A total of 146 eyes of 90 patients with glaucoma were recruited consecutively. The CH measurements were acquired at baseline and 4-months interval using the Ocular Response Analyzer (Reichert Instruments, Depew, NY). Eyes were imaged by CSLO (Heidelberg Retinal Tomograph [HRT]; Heidelberg Engineering, GmbH, Dossenheim, Germany) and SD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec AG, Dublin, CA) at approximately 4-month intervals for measurement of ONH surface topography and RNFL thickness, respectively. Significant ONH surface depression and RNFL thinning were defined with reference to Topographic Change Analysis (TCA) with HRT and Guided Progression Analysis (GPA) with Cirrus HD-OCT, respectively. Multivariate cox proportional hazards models were used to investigate whether CH is a risk factor for ONH surface depression and RNFL progression after adjusting potential confounding factors. All patients with glaucoma were followed for an average of 6.76 years (range, 4.56–7.61 years). Sixty-five glaucomatous eyes (44.5%) of 49 patients showed ONH surface depression, 55 eyes (37.7%) of 43 patients had progressive RNFL thinning and 20 eyes (13.7%) of 17 patients had visual field progression. In the cox proportional hazards model, after adjusting baseline diastolic IOP, CCT, age, baseline disc area and baseline MD, baseline CH was significantly associated with ONH surface depression and visual field progression (HR = 0.71, P = 0.014 and HR = 0.54, P = 0.018, respectively), but not with RNFL thinning (HR = 1.03, P = 0.836). For each 1-mmHg decrease in baseline CH, the hazards for ONH surface depression increase by 29%, and the hazards for visual field progression increase by 46%. The CH measurements were significantly associated with risk of glaucoma progression. Eyes with a lower CH were significantly associated with an increased risk of ONH surface depression and visual field progression in glaucoma patients.
Collapse
|
6
|
Zimprich L, Diedrich J, Bleeker A, Schweitzer JA. Corneal Hysteresis as a Biomarker of Glaucoma: Current Insights. Clin Ophthalmol 2020; 14:2255-2264. [PMID: 32848355 PMCID: PMC7429407 DOI: 10.2147/opth.s236114] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/21/2020] [Indexed: 12/17/2022] Open
Abstract
The diagnosis and management of glaucoma has long been dependent on making decisions based on family history, optic nerve head evaluation, intraocular pressure, visual field testing, and optical coherence testing. Other pieces to aid in understanding glaucoma have presented throughout the years, including the role of corneal thickness. The discussion and debate on the mechanism of glaucoma have been attributed to resistance at the level of the conventional outflow pathway, perfusion pressure to the optic nerve head, cerebral spinal fluid pressure, and many more. Another piece that has emerged is corneal hysteresis, an assessment of the cornea’s ability to absorb and dissipate energy. There is abundant published literature supporting corneal hysteresis being associated with the presence and severity of glaucoma, the structural and functional progression of glaucoma, and the conversion to glaucoma. The supported data in these studies add another piece, corneal hysteresis, to consider in the diagnosis and management of glaucoma.
Collapse
Affiliation(s)
| | | | - Adam Bleeker
- University of South Dakota Sanford School of Medicine, Vermillion, SD 57069, USA
| | | |
Collapse
|
7
|
Abstract
A correct diagnosis of glaucoma established at initial visits.
Collapse
|
8
|
Asejczk-Widlicka M, Jóźwik A, Kasprzak H, Sobczak M, Pierscionek BK. Data analysis of the ocular response analyzer for improved distinction and detection of glaucoma. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:B71-B76. [PMID: 31044958 DOI: 10.1364/josaa.36.000b71] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 01/28/2019] [Indexed: 06/09/2023]
Abstract
The purpose of this study was to evaluate the clinical utility of the output parameters of the ocular response analyzer (ORA) and those calculated from the raw ORA in subjects with healthy eyes and those with suspected glaucoma, and in patients with two types of glaucoma. The raw ORA data were analyzed using a custom software that included the Gaussian filtering of applanation curves for three different window sizes. To the best of our knowledge, these findings present a novel means of optimizing the use of measurements from the ORA, which can refine the characteristics of corneal biomechanics, enabling a distinction between the types of glaucoma and leading to an improvement in diagnosing and early detection.
Collapse
|
9
|
Abstract
PURPOSE To review and summarize the characteristics of corneal hysteresis (CH) and its relationship with glaucoma. METHODS A PubMed search was carried out using the terms "corneal hysteresis", "glaucoma", and "biomechanics". Up to March 2018, all studies published in English are included in this review. RESULTS The value of CH reflects the ability of corneal tissue to absorb and release energy during bidirectional flattening. It is an important biomechanical parameter of the cornea. The CH value of healthy adults is about 11 mmHg. The measurement of CH is reproducible and different. People have different CH values, which are determined by the shape of the individual's cornea. The study found that all types of glaucoma, including primary open angle glaucoma, angle-closure glaucoma, normal tension glaucoma, congenital glaucoma, binocular asymmetrical glaucoma, CH values are lower than normal people, therefore, CH is therefore a good indicator of glaucoma diagnosis and screening. Lower CH values are associated with thinner retinal nerve fiber layer (RNFL), larger linear cup/disk ratio (LCDR) and degree of optic disc defect. A lower CH value can also result in a lower visual field index. CH and the basic intraocular pressure play a synergistic role in the progression of glaucoma. The study found that CH can change with changes in basic intraocular pressure, means CH increases when intraocular pressure decreases, while the CH decreases conversely when intraocular pressure increases. Most clinical case studies have shown a decrease in CH after LASER refractive surgery. CH has its limitations, such as corneal damage or corneal surgery, but in general, CH is a risk factor for glaucoma progression. CONCLUSION CH is used as a predictor of glaucoma risk and may help to assess the effect of corneal thickness on intraocular pressure. The clinical significance of CH in the diagnosis and efficacy of glaucoma will become more explicit. In the future, CH can also play an important role in the diagnosis and treatment of glaucoma.
Collapse
|
10
|
Bedggood P, Tanabe F, McKendrick AM, Turpin A, Anderson AJ, Bui BV. Optic nerve tissue displacement during mild intraocular pressure elevation: its relationship to central corneal thickness and corneal hysteresis. Ophthalmic Physiol Opt 2018; 38:389-399. [DOI: 10.1111/opo.12568] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Accepted: 05/08/2018] [Indexed: 01/29/2023]
Affiliation(s)
- Phillip Bedggood
- Department of Optometry and Vision Sciences The University of Melbourne Parkville Australia
| | - Fumi Tanabe
- Faculty of Medicine Department of Ophthalmology Kindai University Osaka‐Sayama Japan
| | - Allison M. McKendrick
- Department of Optometry and Vision Sciences The University of Melbourne Parkville Australia
| | - Andrew Turpin
- School of Computing and Information Systems The University of Melbourne Parkville Australia
| | - Andrew J. Anderson
- Department of Optometry and Vision Sciences The University of Melbourne Parkville Australia
| | - Bang V. Bui
- Department of Optometry and Vision Sciences The University of Melbourne Parkville Australia
| |
Collapse
|
11
|
Gizzi C, Cellini M, Campos EC. In vivo assessment of changes in corneal hysteresis and lamina cribrosa position during acute intraocular pressure elevation in eyes with markedly asymmetrical glaucoma. Clin Ophthalmol 2018; 12:481-492. [PMID: 29588569 PMCID: PMC5858548 DOI: 10.2147/opth.s151532] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Purpose To investigate the biomechanical response of the cornea, lamina cribrosa (LC), and prelaminar tissue (PT) to an acute intraocular pressure (IOP) increase in patients with markedly asymmetrical glaucoma and in healthy controls. Patients and methods A total of 24 eyes of 12 patients with markedly asymmetrical primary open-angle glaucoma (POAG) and 12 eyes of 12 healthy patients were examined with spectral-domain optical coherence tomography (SD-OCT) and ocular response analyzer (ORA) at baseline and during acute IOP elevation by means of an ophthalmodynamometer. The displacement of the LC and PT and the change in corneal hysteresis (CH) and corneal resistance factor (CRF) were evaluated. Results Following a mean IOP increase of 12.3±2.4 mmHg, eyes with severe glaucoma demonstrated an overall mean anterior displacement of the LC (−6.58±26.09 µm) as opposed to the posterior laminar displacement in eyes with mild glaucoma (29.08±19.28 µm) and in healthy eyes (30.3±10.9; p≤0.001 and p=0.001, respectively). The PT displaced posteriorly during IOP elevation in all eyes. The CH decreased in eyes with severe glaucoma during IOP elevation (from 9.30±3.65 to 6.92±3.04 mmHg; p=0.012), whereas the CRF increased markedly in eyes with mild glaucoma (from 8.61±2.30 to 12.38±3.64; p=0.002) and in eyes with severe glaucoma (from 9.02±1.48 to 15.20±2.06; p=0.002). The increase in CRF correlated with the anterior displacement of the LC in eyes with severe glaucoma. Conclusion Eyes with severe glaucoma exhibited a mean overall anterior displacement of the anterior laminar surface, while eyes with mild glaucoma and healthy eyes showed a posterior displacement of the LC during IOP elevation. The CH decreased significantly from baseline only in eyes with severe glaucoma, but the CRF increased significantly in all glaucomatous eyes. The CRF increase correlated with the anterior displacement of the LC in eyes with severe glaucoma.
Collapse
Affiliation(s)
- Corrado Gizzi
- Department of Experimental, Diagnostic and Speciality Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
| | - Mauro Cellini
- Department of Experimental, Diagnostic and Speciality Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
| | - Emilio C Campos
- Department of Experimental, Diagnostic and Speciality Medicine, Ophthalmology Service, University of Bologna, Bologna, Italy
| |
Collapse
|
12
|
Relationship between corneal biomechanical properties and structural biomarkers in patients with normal-tension glaucoma: a retrospective study. BMC Ophthalmol 2018; 18:7. [PMID: 29334923 PMCID: PMC5769305 DOI: 10.1186/s12886-018-0673-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 01/04/2018] [Indexed: 11/10/2022] Open
Abstract
Background We evaluated the relationships between corneal biomechanical properties and structural parameters in patients with newly diagnosed, untreated normal-tension glaucoma (NTG). Methods All subjects were evaluated using an Ocular Response Analyzer (ORA) measuring corneal hysteresis (CH) and the corneal resistance factor (CRF). Central corneal thickness (CCT), Goldmann applanation tonometric (GAT) data, axial length, and the spherical equivalent (SE), were also measured. Confocal scanning laser ophthalmoscopy was performed with the aid of a Heidelberg retina tomograph (HRT III). We sought correlations between HRT parameters and different variables including CCT, CH, and the CRF. Multiple linear regression analysis was performed to identify significant associations between corneal biomechanical properties and optic nerve head parameters. Results We enrolled 95 eyes of 95 NTG patients and 93 eyes of 93 normal subjects. CH and the CRF were significantly lower in more advanced glaucomatous eyes (P = 0.001, P = 0.008, respectively). The rim area, rim volume, linear cup-to-disc ratio (LCDR), and mean retinal nerve fiber layer (RNFL) thickness were significantly worse in more advanced glaucomatous eyes (P < 0.001, P < 0.001, P < 0.001, and P = 0.001). CH was directly associated with rim area, rim volume, and mean RNFL thickness (P = 0.012, P = 0.028, and P = 0.043) and inversely associated with LCDR (P = 0.015), after adjusting for age, axial length, CCT, disc area, GAT data, and SE. However, in normal subjects, there were no significant associations between corneal biomechanical properties and HRT parameters. Conclusions A lower CH is significantly associated with a smaller rim area and volume, a thinner RNFL, and a larger LCDR, independent of disc size, corneal thickness, intraocular pressure, and age.
Collapse
|
13
|
Hidalgo-Aguirre M, Costantino S, Lesk MR. Pilot study of the pulsatile neuro-peripapillary retinal deformation in glaucoma and its relationship with glaucoma risk factors. Curr Eye Res 2017; 42:1620-1627. [PMID: 28937876 DOI: 10.1080/02713683.2017.1362004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To perform a pilot study of the neuro-peripapillary retinal tissue deformation during the cardiac cycle among healthy eyes, ocular hypertensive (OHT), open angle glaucoma suspect (OAG-S), and early open angle glaucoma (EOAG) patients using video rate optical coherence tomography (OCT) image series. METHODS OCT line scan sequences of the same region of the optic nerve head (ONH) were obtained from 15 EOAG, 6 OHT, 10 OAG-S, and 10 healthy age-matched eyes. One eye per patient was studied. Changes in the axial distance between the inferotemporal peripapillary retina and the prelaminar tissue, in time, were determined using an automated custom made algorithm. Linear correlations between this neuro-peripapillary retinal (N-PP) deformation and variables measured during the full ophthalmic examination are analyzed. RESULTS Healthy eyes showed larger N-PP deformation (4.8 ± 1 µm) than the OHT (3.5 ± 0.3 µm, p = 0.015), OAG-S (3.8 ± 0.8 µm, p = 0.045), and EOAG (3.2 ± 0.7 µm, p < 0.001) groups. Eyes with lower ocular pulse amplitude, thinner RNFL's, or worse visual fields showed smaller N-PP deformation, depending on the diagnosis. A linear model to explain deformation within the EOAG group with intraocular pressure and systolic perfusion pressure as predictors was found to be significant (R2 = 0.767, p < 0.001). CONCLUSIONS Smaller mean N-PP deformation was observed in the EOAG, OAG-S, and OHT groups compared to healthy eyes in this pilot study. The measured deformation correlated with risk factors for the glaucomatous optic neuropathy, but these correlations varied depending on the diagnosis. The role of pulsatile neuro-peripapillary retinal deformation in the pathophysiology of OAG remains to be determined.
Collapse
Affiliation(s)
- Maribel Hidalgo-Aguirre
- a Institut National de la Recherche Scientifique centre Energie , Materiaux et Telecommunications , 1650 Boulevard Lionel-Boulet, Varennes , Quebec , J3X 1S2 , Canada.,b Maisonneuve-Rosemont Hospital , Research Center , 5415 L'Assomption, Montreal , Quebec , H1T 2M4 , Canada
| | - Santiago Costantino
- b Maisonneuve-Rosemont Hospital , Research Center , 5415 L'Assomption, Montreal , Quebec , H1T 2M4 , Canada.,c Universite de Montreal , Ophthalmology Department, Faculty of Medicine , 2900 Boulevard Edouard-Montpetit, Montreal , Quebec , H3T 1J4 , Canada
| | - Mark Richard Lesk
- b Maisonneuve-Rosemont Hospital , Research Center , 5415 L'Assomption, Montreal , Quebec , H1T 2M4 , Canada.,c Universite de Montreal , Ophthalmology Department, Faculty of Medicine , 2900 Boulevard Edouard-Montpetit, Montreal , Quebec , H3T 1J4 , Canada
| |
Collapse
|
14
|
Öhnell H, Heijl A, Anderson H, Bengtsson B. Detection of glaucoma progression by perimetry and optic disc photography at different stages of the disease: results from the Early Manifest Glaucoma Trial. Acta Ophthalmol 2017; 95:281-287. [PMID: 27778463 PMCID: PMC5412870 DOI: 10.1111/aos.13290] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 09/12/2016] [Indexed: 12/05/2022]
Abstract
Purpose To compare the earliest detection of progression in visual fields and monoscopic optic disc photographs at different stages of manifest glaucoma. Methods This study evaluated 306 eyes in 249 patients with manifest open‐angle glaucoma included in the Early Manifest Glaucoma Trial (EMGT). All patients in the trial were followed up regularly by standard automated perimetry and monoscopic optic disc photography, and the median follow‐up time was 8 years. Progression was assessed in series of optic disc photographs and in series of visual fields using glaucoma change probability maps and the predefined EMGT progression criterion. The proportion of progressions detected first in visual fields and the proportion detected first in optic disc photographs were compared at different stages of glaucoma severity defined by the perimetric mean deviation (MD) of the baseline visual field. Results Assessment of 210 eyes with early visual field loss, 83 eyes with moderate field loss, and 13 eyes with advanced field loss showed that, among the eyes exhibiting progression, the progression was detected first in the visual field in 80%, 79% and 100%, respectively. The predominance of visual field progressions at all stages was still apparent when using narrower (3‐dB) MD intervals for staging. Conclusion In the EMGT material on eyes with manifest open‐angle glaucoma, the initial progression was detected much more often in the visual field series than in the optic disc photographs at all stages of disease.
Collapse
Affiliation(s)
- HannaMaria Öhnell
- Department of ophthalmology; Lund University, Skane University Hospital; Malmö Sweden
| | - Anders Heijl
- Department of Clinical Sciences in Malmö, Ophthalmology; Faculty of Medicine; Lund University; Malmö Sweden
| | - Harald Anderson
- Department of Clinical Sciences Lund, Cancer Epidemiology; Faculty of Medicine; Lund University; Lund Sweden
| | - Boel Bengtsson
- Department of Clinical Sciences in Malmö, Ophthalmology; Faculty of Medicine; Lund University; Malmö Sweden
| |
Collapse
|
15
|
Öhnell H, Heijl A, Brenner L, Anderson H, Bengtsson B. Structural and Functional Progression in the Early Manifest Glaucoma Trial. Ophthalmology 2016; 123:1173-80. [PMID: 26949119 PMCID: PMC4877258 DOI: 10.1016/j.ophtha.2016.01.039] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 12/10/2015] [Accepted: 01/26/2016] [Indexed: 10/22/2022] Open
Abstract
PURPOSE To elucidate the temporal relationship between detection of glaucomatous optic disc progression, as assessed by fundus photography, and visual field progression. DESIGN Prospective, randomized, longitudinal trial. PARTICIPANTS Three hundred six study eyes with manifest glaucoma with field loss and 192 fellow eyes without any field defect at the start of the trial, from a total of 249 subjects included in the Early Manifest Glaucoma Trial (EMGT), were assessed. METHODS Evaluation of visual field progression and optic disc progression during an 8-year follow-up period. Three graders independently assessed optic disc progression in optic disc photographs. Visual field progression was assessed using glaucoma change probability maps and the EMGT progression criterion. MAIN OUTCOME MEASURES Time to detection of visual field progression and optic disc progression. RESULTS Among study eyes with manifest glaucoma, progression was detected in the visual field first in 163 eyes (52%) and in the optic disc first in 39 eyes (12%); in 1 eye (0%), it was found simultaneously with both methods. Among fellow eyes with normal fields, progression was detected in the visual field first in 28 eyes (15%) and in the optic disc first in 34 eyes (18%); in 1 eye (1%), it occurred simultaneously. CONCLUSIONS In eyes with manifest glaucoma, progression in the visual field was detected first more than 4 times as often as progression in the optic disc. Among fellow eyes without visual field loss at baseline, progression was detected first as frequently in the optic disc as in the visual field.
Collapse
Affiliation(s)
- HannaMaria Öhnell
- Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Sweden.
| | - Anders Heijl
- Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Sweden
| | | | - Harald Anderson
- Department of Clinical Sciences Lund, Cancer Epidemiology, Lund University, Sweden
| | - Boel Bengtsson
- Department of Clinical Sciences in Malmö, Ophthalmology, Lund University, Sweden
| |
Collapse
|
16
|
Abstract
PURPOSE OF REVIEW Glaucoma is a leading cause of irreversible blindness worldwide. It is estimated that roughly 60.5 million people had glaucoma in 2010 and that this number is increasing. Many patients continue to lose vision despite apparent disease control according to traditional risk factors. The purpose of this review is to discuss the recent findings with regard to corneal hysteresis, a variable that is thought to be associated with the risk and progression of glaucoma. RECENT FINDINGS Low corneal hysteresis is associated with optic nerve and visual field damage in glaucoma and the risk of structural and functional glaucoma progression. In addition, hysteresis may enhance intraocular pressure (IOP) interpretation: low corneal hysteresis is associated with a larger magnitude of IOP reduction following various glaucoma therapies. Corneal hysteresis is dynamic and may increase in eyes after IOP-lowering interventions are implemented. SUMMARY It is widely accepted that central corneal thickness is a predictive factor for the risk of glaucoma progression. Recent evidence shows that corneal hysteresis also provides valuable information for several aspects of glaucoma management. In fact, corneal hysteresis may be more strongly associated with glaucoma presence, risk of progression, and effectiveness of glaucoma treatments than central corneal thickness.
Collapse
|
17
|
Xu G, Weinreb RN, Leung CK. Optic Nerve Head Deformation in Glaucoma. Ophthalmology 2014; 121:2362-70. [DOI: 10.1016/j.ophtha.2014.06.035] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 02/10/2014] [Accepted: 06/23/2014] [Indexed: 11/25/2022] Open
|
18
|
Alwadani F. Effect of Tight Naqab on Intraocular Pressure: A Prospective Study. JOURNAL OF MEDICAL SCIENCES 2013. [DOI: 10.3923/jms.2013.839.842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
19
|
Russo A, Katsanos A, Riva I, Floriani I, Biagioli E, Quaranta L. Topographic optic disc changes after successful trabeculectomy evaluated using spectral domain optical coherence tomography. J Ocul Pharmacol Ther 2013; 29:870-5. [PMID: 24070365 DOI: 10.1089/jop.2013.0127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To investigate topographic optic disc changes after surgical intraocular pressure (IOP) reduction in adults with open angle glaucoma (OAG). METHODS Optic discs of patients with advanced primary open angle or exfoliation glaucoma were imaged using optical coherence tomography within 1 week before trabeculectomy. Patients were rescanned 1 week, 1 month, and 1 year after surgery. Maximum cup depth (MCD), and average cup depth (ACD) were calculated. RESULTS Twenty-two eyes from 20 patients (age, 70.5 ± 10.6 years; average mean defect of visual field, -15.0 ± 9.8 dB) were followed up for 1 year. The IOP decreased from 22.1 ± 2.8 mmHg at baseline to 11.5±2.6 mmHg 1 year following surgery (P<0.001). One-week and 1-month postoperative IOPs were 11.2 ± 2.8 and 11.2 ± 3.5 mmHg, respectively (P<0.001). Compared to the baseline values (356 ± 172 μm), postoperative ACD showed a significant decrease at 1 week (312 ± 164 μm; P<0.001) and 1 month (338 ± 175 μm; P=0.007) after surgery, but not at 1 year (339 ± 176 μm; P=0.354). Similarly, MCD significantly decreased from baseline (477 ± 190 μm) 1 week (431 ± 203 μm; P=0.029) and 1 month (448 ± 198 μm; P=0.047) after the surgery, but not after 1 year (479 ± 188 μm; P=1.0). CONCLUSIONS Trabeculectomy reduces IOP in eyes with advanced OAG, which induces topographic optic disc changes. Such optic disc changes became less pronounced over time and were no longer detectable 1 year after surgery.
Collapse
Affiliation(s)
- Andrea Russo
- 1 Centre for the Study of Glaucoma, University of Brescia , Brescia, Italy
| | | | | | | | | | | |
Collapse
|
20
|
Hugar DL, Ivanisevic A. Materials characterization and mechanobiology of the eye. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2013; 33:1867-75. [PMID: 23498207 DOI: 10.1016/j.msec.2013.02.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 01/07/2013] [Accepted: 02/05/2013] [Indexed: 12/29/2022]
Abstract
The eye responds to a great deal of internal and external stimuli throughout its normal function. Due to this, a mechanical or chemical analysis alone is insufficient. A systematic materials characterization is needed. A mechanobiological approach is required for a full understanding of the unique properties and function of the eye. This review compiles the mechanical properties of select eye components, summarizes mechanical and chemical testing platforms, and overviews modeling approaches. Analysis is done across studies, experimental methods, and between species in order to summarize what is known about the mechanobiology of the eye. Several opportunities for future research are identified.
Collapse
Affiliation(s)
- Daniel L Hugar
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | | |
Collapse
|
21
|
Prata TS, Lima VC, Guedes LM, Biteli LG, Teixeira SH, de Moraes CG, Ritch R, Paranhos A. Association between corneal biomechanical properties and optic nerve head morphology in newly diagnosed glaucoma patients. Clin Exp Ophthalmol 2013; 40:682-8. [PMID: 22429725 DOI: 10.1111/j.1442-9071.2012.02790.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND To investigate the association between corneal biomechanics and optic nerve head morphology in newly diagnosed primary open-angle glaucoma patients. DESIGN Hospital based prospective study. PARTICIPANTS Forty-two untreated newly diagnosed primary open-angle glaucoma patients. METHODS Patients underwent corneal hysteresis measurement using the Ocular Response Analyzer and confocal scanning laser ophthalmoscopy for optic nerve head topography evaluation. One eye was selected randomly for analysis. Data collected included age, race, gender, intraocular pressure and central corneal thickness. MAIN OUTCOME MEASURES Multiple regression analysis (controlling for baseline intraocular pressure and disc area) was used to investigate factors associated with the following optic nerve head topographic parameters: linear cup-to-disc ratio and mean cup depth. RESULTS Mean age of participants was 66.7 ± 11.8 years. Corneal hysteresis was the only factor significantly associated with both mean cup depth (correlation coefficient [r] = -0.34, P = 0.03) and cup-to-disc ratio (r = -0.41, P = 0.01). Central corneal thickness was significantly associated with mean cup depth (r = -0.35, P = 0.02), but not with cup-to-disc ratio (r = -0.25, P = 0.13). Although a trend towards a positive association between age and cup-to-disc ratio was identified (r = 0.26, P = 0.08), age was not significantly associated with mean cup depth (r = 0.06, P = 0.72). When comparing fellow eyes of patients with bilateral glaucoma, the eye with higher corneal hysteresis had smaller cup-to-disc ratio in 75% of the cases. CONCLUSIONS In untreated newly diagnosed primary open-angle glaucoma patients, those with thinner corneas and mainly lower corneal hysteresis values had a larger cup-to-disc ratio and deeper cup, independently of intraocular pressure values and disc size.
Collapse
Affiliation(s)
- Tiago S Prata
- Department of Ophthalmology, Federal University of São Paulo Hospital Medicina dos Olhos, São Paulo, Brazil.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Hayes DD, Teng CC, de Moraes CG, Tello C, Liebmann JM, Ritch R. Corneal hysteresis and Beta-zone parapapillary atrophy. Am J Ophthalmol 2012; 153:358-362.e1. [PMID: 21920490 DOI: 10.1016/j.ajo.2011.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/28/2011] [Accepted: 06/29/2011] [Indexed: 11/16/2022]
Abstract
PURPOSE To evaluate the relationship between β-zone parapapillary atrophy (βPPA) and corneal hysteresis (CH) in patients with glaucoma. DESIGN Prospective, cross-sectional study. METHODS Glaucoma patients aged 18 to 90 years with disc photographs within 12 months of the study visit were consecutively enrolled. Exclusion criteria included ocular surgery other than clear corneal phacoemulsification, myopia >6 diopters, contact lens use, and corneal abnormality. CH was measured using the Ocular Response Analyzer (ORA). Disc photographs were evaluated in a masked fashion for βPPA. RESULTS We enrolled 99 patients (mean age 67.6 years; 45 men, 54 women). Univariate analysis showed no significant difference in CH between eyes with and without βPPA (8.72 ± 0.23 vs 8.15 ± 0.27 mm Hg, P = .11). There were no differences in corneal resistance factor (CRF) (P = .47), central corneal thickness (CCT) (P = .11), ORA wave score (P = .23), age (P = .23), sex (P = .40), IOP (P = .86), or visual field mean deviation (VFMD) (P = .45). Eyes with βPPA were more myopic (-1.49 ± 0.27 vs -0.22 ± 0.31 diopters, P = .003). Multivariate analysis showed no significant difference in CH between eyes with and without βPPA (P = .38). Eyes with asymmetric βPPA also showed no significant difference in CH (8.97 ± 0.22 vs 9.10 ± 0.22 mm Hg, P = .69). CONCLUSIONS We found no significant differences in CH between eyes with and without βPPA or between fellow eyes with asymmetric βPPA.
Collapse
Affiliation(s)
- Daniel D Hayes
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, New York, USA
| | | | | | | | | | | |
Collapse
|