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Li X. Changes in corneal biomechanics in patients with glaucoma: a systematic review and meta-analysis. BMC Ophthalmol 2024; 24:168. [PMID: 38622519 PMCID: PMC11017643 DOI: 10.1186/s12886-024-03443-4] [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: 09/22/2023] [Accepted: 04/09/2024] [Indexed: 04/17/2024] Open
Abstract
INTRODUCTION Corneal biomechanics has been implicated in a variety of ocular diseases. The purpose of this study was to evaluate the relationship between the glaucoma and corneal biomechanical properties, and exploring the value of corneal biomechanics in the diagnosis and follow-up of glaucoma diseases. METHODS We searched studies in PubMed, EMBASE, Web of Science and clinicaltrials.gov., as of October 8, 2022. Only English studies were included, without publication time limit. We also searched the reference lists of published reviews. This meta-analysis was conducted with random-effects models, we used mean difference(MD) to evaluate the outcome, and the heterogeneity was assessed with the I2 statistic. Subgroup analyses were performed under the appearance of high heterogeneity. We used 11 items to describe the characteristics of included studies, publication bias was performed through the Egger's test. The quality assessment were evaluated by Newcastle-Ottawa Scale(NOS) items. RESULTS A total of 27 eligible studies were identified for data synthesis and assessment. The result of meta-analysis showed that in the comparison of included indicators, the corneal biomechanics values of glaucoma patients were statistically lower than those of normal subjects in a similar age range. The covered indicators included central corneal thickness(CCT) (MD = -8.34, 95% CI: [-11.74, -4.94]; P < 0.001), corneal hysteresis(CH)(MD = -1.54, 95% CI: [-1.88, -1.20]; P < 0.001), corneal resistance factor(CRF)( MD = -0.82, 95% CI: [-1.21, -0.44]; P < 0.001), and intraocular pressure(IOP)( corneal-compensated intraocular pressure (IOPcc): MD = 2.45, 95% CI: [1.51, 3.38]; P < 0.001); Goldmann-correlated intraocular pressure (IOPg): MD = 1.30, 95% CI: [0.41, 2.20]; P = 0.004), they all showed statistical difference. While the value of axial length(AL) did not show statistically different(MD = 0.13, 95% CI: [-0.24, 0.50]; P = 0.48). CONCLUSION Corneal biomechanics are associated with glaucoma. The findings can be useful for the design of glaucoma screening, treatment and prognosis.
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Affiliation(s)
- Xinru Li
- Department of Ophthalmology, The First People's Hospital of Yongkang Affiliated to Hangzhou Medical College, Yongkang, 321300, Zhejiang, P. R. China.
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Elhusseiny AM, Scarcelli G, Saeedi OJ. Corneal Biomechanical Measures for Glaucoma: A Clinical Approach. Bioengineering (Basel) 2023; 10:1108. [PMID: 37892838 PMCID: PMC10604716 DOI: 10.3390/bioengineering10101108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 10/29/2023] Open
Abstract
Over the last two decades, there has been growing interest in assessing corneal biomechanics in different diseases, such as keratoconus, glaucoma, and corneal disorders. Given the interaction and structural continuity between the cornea and sclera, evaluating corneal biomechanics may give us further insights into the pathogenesis, diagnosis, progression, and management of glaucoma. Therefore, some authorities have recommended baseline evaluations of corneal biomechanics in all glaucoma and glaucoma suspects patients. Currently, two devices (Ocular Response Analyzer and Corneal Visualization Schiempflug Technology) are commercially available for evaluating corneal biomechanics; however, each device reports different parameters, and there is a weak to moderate agreement between the reported parameters. Studies are further limited by the inclusion of glaucoma subjects taking topical prostaglandin analogues, which may alter corneal biomechanics and contribute to contradicting results, lack of proper stratification of patients, and misinterpretation of the results based on factors that are confounded by intraocular pressure changes. This review aims to summarize the recent evidence on corneal biomechanics in glaucoma patients and insights for future studies to address the current limitations of the literature studying corneal biomechanics.
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Affiliation(s)
- Abdelrahman M. Elhusseiny
- Department of Ophthalmology, Harvey and Bernice Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Osamah J. Saeedi
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Mohammadzadeh V, Moghimi S, Nishida T, Mahmoudinezhad G, Kamalipour A, Micheletti E, Zangwill L, Weinreb RN. Effect of Corneal Hysteresis on the Rates of Microvasculature Loss in Glaucoma. Ophthalmol Glaucoma 2023; 6:177-186. [PMID: 35995420 DOI: 10.1016/j.ogla.2022.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 07/19/2022] [Accepted: 08/12/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate the association between corneal hysteresis (CH) and rates of optic nerve head whole image capillary density (wiCD) loss over time in open-angle glaucoma (OAG). DESIGN Observational cohort. PARTICIPANTS One hundred seventy-four eyes (122 OAG and 52 glaucoma suspect eyes) from 112 patients over more than 2 years and 4 visits or more. METHODS Baseline CH measurements were acquired with the Ocular Response Analyzer. Linear mixed-effect models were designed to investigate the effect of CH, average intraocular pressure (IOP) during follow-up, and baseline visual field (VF) mean deviation (MD) on the rates of wiCD loss and circumpapillary retinal nerve fiber layer (cpRNFL) thinning over time, while adjusting for confounders. Interaction between CH or baseline MD and average IOP during follow-up were included in final models to evaluate the effect of baseline MD or average IOP during follow-up on structural changes for different values of CH. MAIN OUTCOME MEASURE Effect of CH, IOP, and baseline MD on the rates of wiCD loss and cpRNFL thinning over time. RESULTS The average follow-up time was 3.9 years. In the multivariable model, non-Black race, higher average IOP during follow-up, lower baseline CH, lower baseline VF MD, and higher numbers of IOP-lowering medications were associated with faster rates of wiCD loss over time. For CH values 6 mmHg and 12 mmHg, every 1-mmHg increase in average IOP during follow-up was associated with 0.23% per year faster and 0.07% per year slower rates of wiCD loss over time, respectively. While every 1-mmHg decrease in CH was associated with 1.89% per year faster rate of wiCD loss for MD of -12 dB, it was associated with 0.81% per year faster rate of wiCD loss for MD of -3 dB. CONCLUSION Lower CH values were significantly associated with faster rates of wiCD loss over time. In eyes with lower CH, both higher average IOP during follow-up and more severe glaucoma damage at baseline were associated with faster rates of wiCD loss and cpRNFL thinning. These results support CH as a useful parameter for risk assessment of glaucoma progression. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Vahid Mohammadzadeh
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California
| | - Sasan Moghimi
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California
| | - Takashi Nishida
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California
| | - Golnoush Mahmoudinezhad
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California
| | - Alireza Kamalipour
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California
| | - Eleonora Micheletti
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California
| | - Linda Zangwill
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, La Jolla, California.
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Liu MX, Zhou M, Li DL, Dong XX, Liang G, Pan CW. Corneal Biomechanics in Primary Open Angle Glaucoma and Ocular Hypertension: A Systematic Review and Meta-analysis. J Glaucoma 2023; 32:e24-e32. [PMID: 36583701 DOI: 10.1097/ijg.0000000000002170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 12/07/2022] [Indexed: 12/31/2022]
Abstract
PRCIS Normal tension glaucoma patients had softer corneas than normal controls, whereas high-tension glaucoma and ocular hypertension patients had stiffer corneas. PURPOSE To comprehensively identify the corneal biomechanical differences of patients with primary open angle glaucoma (POAG) and ocular hypertension (OHT) using the Ocular Response Analyzer or the Corvis ST. METHODS The electronic databases PubMed, Embase, and Web of Science were comprehensively searched for studies comparing corneal biomechanical differences between POAG and OHT patients with normal controls by Ocular Response Analyzer or Corvis ST. The weighted mean differences and 95% confidence intervals (CIs) were calculated. Subgroup analyses were performed according to the subtypes of POAG, including high-tension glaucoma (HTG) and normal tension glaucoma (NTG). RESULTS Thirty-one case-control studies were ultimately included, with 2462 POAG patients, 345 OHT patients, and 3281 normal controls. The corneal hysteresis (CH), corneal resistance factor (CRF), and highest concavity time (HC-t) were all lower in POAG patients than in normal controls. The CH, time at the second applanation (A2t), HC-t, highest concavity radius (HC-R), and deformation amplitude at the highest concavity (HC-DA) were lower in OHT patients, while the CRF, time at the first applanation (A1t), and stiffness parameter at the first applanation (SP-A1) were greater in OHT patients than in normal controls. The subgroup analyses showed that the CH, A2t, length at the second applanation (A2L), and HC-DA were lower in HTG, and the CH, CRF, A1t, and HC-t were lower in NTG patients than in normal controls. CONCLUSION The corneas of NTG patients are more deformable than normal controls, whereas the corneas of HTG and OHT patients are stiffer.
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Affiliation(s)
- Min-Xin Liu
- School of Public Health, Medical College of Soochow University, Suzhou
| | - Miao Zhou
- Department of Ophthalmology, Peking University People's Hospital, Beijing
| | - Dan-Lin Li
- School of Public Health, Medical College of Soochow University, Suzhou
| | - Xing-Xuan Dong
- School of Public Health, Medical College of Soochow University, Suzhou
| | - Gang Liang
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, China
| | - Chen-Wei Pan
- School of Public Health, Medical College of Soochow University, Suzhou
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Marcellán MC, Remón L, Ávila FJ. Corneal hysteresis and intraocular pressure are altered in silicone-hydrogel soft contact lenses wearers. Int Ophthalmol 2022; 42:2801-2809. [PMID: 35355168 PMCID: PMC9420097 DOI: 10.1007/s10792-022-02270-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 03/12/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this work is to determinate the effects in the physical parameters in terms of intraocular pressure (IOP) and central corneal thickness (CCT) and corneal biomechanics in terms of corneal resistance factor (CRF) and corneal hysteresis (CH) of wearing silicone-hydrogel soft contact lenses (SiH-CLs) in young adult subjects during a short-term follow-up. METHODS 40 eyes of 20 healthy patients with a mean age of 22.87 ± 4.14 were involved in this study. Subjects with corneal diseases, dry eye, irregular astigmatism or who have been previous contact lens wearers were excluded. The ocular response analyzer (Reichert Ophthalmic Instruments) was used to measure CH, CRF and IOP and Scheimpflug imaging (the GALILEI™ Dual Scheimpflug camera analyzer, Ziemer) was used to measure CCT before and 10 days (Group 1) and 20 days (Group 2) after wearing the SiH-CLs. RESULTS IOP was significantly decreased 10 days after using the SiH-CLs (p = 0.009). Within the 20 days' period, Group 2 revealed an even more pronounced decrease in IOP (p = 0.003) while CH increased significantly (p = 0.04). CCT and CRF did not show a significant change during the period of SiH-CLs use. Our finding allowed obtaining an empirical expression that relates IOP, CCT, CRF and CH within a biomechanical compensation experimental model. CONCLUSIONS Corneal biomechanical parameters and physical properties of the cornea may be altered due to SiH-CLs use. Our findings could have an impact on the management of glaucoma progression and ocular hypertension.
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Affiliation(s)
| | - Laura Remón
- Departamento de Física Aplicada, Universidad de Zaragoza, C/ Pedro Cerbuna, 12, 50009, Zaragoza, Spain
| | - Francisco J Ávila
- Departamento de Física Aplicada, Universidad de Zaragoza, C/ Pedro Cerbuna, 12, 50009, Zaragoza, Spain.
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Jóźwik A, Przeździecka-Dołyk J, Wałek E, Czerniak M, Asejczyk M. Corneal Behavior during Tonometer Measurement during the Water Drinking Test in Eyes with XEN GelStent in Comparison to Non-Implanted Eyes. J Clin Med 2022; 11:jcm11112962. [PMID: 35683350 PMCID: PMC9181234 DOI: 10.3390/jcm11112962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/15/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
Biomechanics of the cornea have significant influences on the non-contact measurement of the intraocular pressure. The corneal behaviour during tonometry is a fundamental factor in estimating its value. The aim of the study was to analyse the behaviour of the cornea during tonometric measurement with the forced change in intraocular pressure during the water drinking test. Ocular Response Analyser (Reichert) was used to the measurement. Besides four basic parameters connected with intraocular pressure (IOPg, IOPcc) and biomechanics (corneal hysteresis CH and corneal resistance factor (CRF), other parameters representing the behaviour of the cornea during a puff of air were analysed. There were 47 eyes included in the study, including 27 eyes with a XEN GelStent implanted and 20 without it. The eyes of people with monocular implementation were the reference group. The values of analysed parameters were compared before and after 10, 25, 40, and 55 min after drinking the water. The intraocular pressure increased by 2.4 mmHg (p < 0.05) for eyes with a XEN stent and 2.2 mmHg for eyes without a stent (p < 0.05) in the tenth minute after drinking of water. This change caused a decreasing of corneal hysteresis (p < 0.05) without significant changes in the corneal resistance factor (p > 0.05). Corneal hysteresis changed similarly in the reference group and the group with a XEN GelStent. The analysis of additional parameters showed a difference in the behaviour of the cornea in eyes with a XEN GelStent in comparison to the corneas of eyes without a stent. This was particularly visible in the analysis of the cornea’s behaviour during the second applanation, when the cornea returns to its baseline state after deformation caused by air puff tonometry.
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Affiliation(s)
- Agnieszka Jóźwik
- Department of Optics and Photonics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (A.J.); (M.C.); (M.A.)
| | - Joanna Przeździecka-Dołyk
- Department of Optics and Photonics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (A.J.); (M.C.); (M.A.)
- Department of Ophthalmology, Wroclaw Medical University, Borowska 213, 50-556 Wrocław, Poland;
- Correspondence:
| | - Ewa Wałek
- Department of Ophthalmology, Wroclaw Medical University, Borowska 213, 50-556 Wrocław, Poland;
| | - Magdalena Czerniak
- Department of Optics and Photonics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (A.J.); (M.C.); (M.A.)
| | - Magdalena Asejczyk
- Department of Optics and Photonics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland; (A.J.); (M.C.); (M.A.)
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Corneal Hysteresis, Intraocular Pressure, and Progression of Glaucoma: Time for a “Hyst-Oric” Change in Clinical Practice? J Clin Med 2022; 11:jcm11102895. [PMID: 35629021 PMCID: PMC9148097 DOI: 10.3390/jcm11102895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/14/2022] [Accepted: 05/15/2022] [Indexed: 12/04/2022] Open
Abstract
It is known that as people age their tissues become less compliant and the ocular structures are no different. Corneal Hysteresis (CH) is a surrogate marker for ocular compliance. Low hysteresis values are associated with optic nerve damage and visual field loss, the structural and functional components of glaucomatous optic neuropathy. Presently, a range of parameters are measured to monitor and stratify glaucoma, including intraocular pressure (IOP), central corneal thickness (CCT), optical coherence tomography (OCT) scans of the retinal nerve fibre layer (RNFL) and the ganglion cell layer (GCL), and subjective measurement such as visual fields. The purpose of this review is to summarise the current evidence that CH values area risk factor for the development of glaucoma and are a marker for its progression. The authors will explain what precisely CH is, how it can be measured, and the influence that medication and surgery can have on its value. CH is likely to play an integral role in glaucoma care and could potentially be incorporated synergistically with IOP, CCT, and visual field testing to establish risk stratification modelling and progression algorithms in glaucoma management in the future.
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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.
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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
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Glaucoma – risk factors and current challenges in the diagnosis of a leading cause of visual impairment. Maturitas 2022; 163:15-22. [DOI: 10.1016/j.maturitas.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/01/2022] [Accepted: 05/09/2022] [Indexed: 11/21/2022]
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Sallam MA, Elghareib ME. Use of corneal hysteresis and corneal resistance factor in target intraocular pressure estimation in patients with early primary open-angle glaucoma. Int Ophthalmol 2021; 42:891-902. [PMID: 34633607 DOI: 10.1007/s10792-021-02070-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE To introduce a new method for estimation of the target intraocular pressure (TIOP) in naïve eyes with early primary open-angle glaucoma (POAG) using corneal hysteresis (CH) and corneal resistance factor (CRF). METHODS A prospective quasi-experimental study was conducted on naïve 90 eyes of 45 patients who were newly diagnosed with early primary open-angle glaucoma (POAG). They were compared to 72 eyes of 36 normal subjects. The TIOP was determined for each eye. The IOP Goldmann (IOPg), IOP corneal-compensated (IOPcc), CH and CRF were estimated by ocular response analyzer (ORA, Reichert) device. Measurements were taken for each patient prior to treatment and after 1, 3, 6, 9 and 12 months of receiving medications; either monotherapy or combination therapy. RESULTS For all patients, there was a significant negative correlation (p < 0.05) between IOP, either IOPg or IOPcc, and CH, while a significant positive relationship (p < 0.05) existed between IOP and CRF. For patients with early POAG, the CH was significantly increased (p ≤ 0.001), while CRF was significantly decreased (p ≤ 0.001) when TIOP was achieved. At IOP levels higher than TIOP, CH value was lower than CRF with a significant negative correlation between them in contrast to controls. This correlation was reversed on reaching TIOP and CH values became higher than CRF similar to controls. CONCLUSION CH, CRF and IOP measured by ORA can be used for TIOP estimation. This provides us with a guide for assessing the effectiveness of medications introduced to patients with POAG.
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Affiliation(s)
- Moataz A Sallam
- Ophthalmology Department, Suez Canal University Hospitals, 4.5 kilo, The Ring Road, Ismailia, 41522 , Egypt.
| | - Mervat E Elghareib
- Ophthalmology Department, Suez Canal University Hospitals, 4.5 kilo, The Ring Road, Ismailia, 41522 , Egypt
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Lopes BT, Bao F, Wang J, Liu X, Wang L, Abass A, Eliasy A, Elsheikh A. Review of in-vivo characterisation of corneal biomechanics. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2021. [DOI: 10.1016/j.medntd.2021.100073] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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Alipour F, Hassanpoor N, Letafatnejad M, Beheshtnejad AH, Mohammadi SF. Tonometry by Ocular Response Analyzer in Keratoconic and Warpage Eyes in Comparison with Normal Eyes. J Curr Ophthalmol 2021; 33:118-123. [PMID: 34409220 PMCID: PMC8365575 DOI: 10.4103/joco.joco_147_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 10/17/2020] [Accepted: 02/06/2021] [Indexed: 11/04/2022] Open
Abstract
Purpose To compare intraocular pressure (IOP) values measured by ocular response analyzer (ORA) in contact lens-induced corneal warpage, normal, and keratoconic eyes. Methods In a prospective, observational case-control study, 94 eyes of 47 warpage-suspected cases and 46 eyes of 23 keratoconic patients were enrolled. Warpage-suspected cases were followed until a definite diagnosis was made (warpage, nonwarpage normal, or keratoconus). ORA tonometry and corneal biomechanics testing were performed for all cases in each visit. We had 2-3 measured corneal-compensated IOP (IOPcc) and Goldmann-correlated IOP (IOPg) for each patient (based on group) with at least 2-week interval. Results After following up of warpage-suspected patients, finally 44 eyes of 22 patients had confirmed soft contact lens-related corneal warpage. Forty-six eyes of 23 people were finally diagnosed as nonwarpage normal eyes. Forty-six eyes of 23 known keratoconus patients were also included for comparison. The demographic and refractive data were not different between the warpage and nonwarpage normal groups but were different in the keratoconus group. Both IOPcc and IOPg were statistically different with the highest value in the warpage group followed by normal and keratoconus groups; the same trend was observed in central corneal thickness (CCT). The mean of IOPg was 14.94 ± 2.65, 13.7 ± 2.33, and 10.86 ± 3 and IOPcc was 15.73 ± 2.4, 15.28 ± 2.43, and 14.08 ± 2.55 in the warpage, normal, and keratoconus groups, respectively. IOPg and IOPcc in the warpage group (based on baseline diagnosis) did not regress to become closer to IOP of normal eyes after discontinuation of contact lens in their follow-up visits (P value for IOPg and IOPcc trends in the warpage group was 0.07 and 0.09 controlling for CCT, respectively). Both IOPcc and IOPg were significantly lower in keratoconic eyes in comparison with normal eyes. After correction for the confounding effect of CCT, a lower IOPcc in keratoconus versus warpage remained significant (P = 0.02). Conclusion Both IOPcc and IOPg were statistically different with the highest value in the warpage group followed by normal and keratoconus groups, just like their CCT. After correction for the confounding effect of CCT, there was no statistically significant difference between the three groups in their measured IOPcc and IOPg except for IOPcc in keratoconus versus warpage (P = 0.02).
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Affiliation(s)
- Fateme Alipour
- Eye Research Center, Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Narges Hassanpoor
- Eye Research Center, Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.,Department of Ophthalmology, Tabriz University of Medical Sciences, Nikookari Eye Hospital, Tabriz, Iran
| | - Moggan Letafatnejad
- Department of Health Services Management, School of Health Management and Information Sciences, Iran University of Medical Sciences, Tehran, Iran
| | - Amir-Hooshang Beheshtnejad
- Eye Research Center, Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed-Farzad Mohammadi
- Eye Research Center, Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Corneal Biomechanical Changes Caused by Acute Elevation of IOP in Eyes with and without Glaucoma. Optom Vis Sci 2021; 98:367-373. [PMID: 33828042 DOI: 10.1097/opx.0000000000001668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Although corneal biomechanical parameters are well linked with glaucoma, their clinical utility has not yet been fully elucidated. This study was designed to provide unique evidence about the dynamic nature of corneal biomechanical parameters and their potential prognostic ability for glaucoma. PURPOSE This study aimed to evaluate the effect of acute intraocular pressure (IOP) elevation on corneal hysteresis (CH) and corneal resistance factor (CRF) and the associations of these biomechanical parameters with glaucomatous disease. METHODS Subjects participating in a prospective, longitudinal glaucoma research study had CH and CRF measured before and during ophthalmodynamometry during visits in the years 2011 to 2012. All participants were diagnosed with primary open-angle glaucoma, ocular hypertension, glaucoma suspect, or normal eyes and had a minimum of 3 years of study participation with at least five reliable visual field (VF) tests. Changes in CH, CRF, and IOP induced by ophthalmodynamometry were compared between diagnostic groups and evaluated for relationships with existing and future glaucomatous VF loss. RESULTS In 248 eyes of 248 subjects followed up for 7.7 ± 2.3 years, ophthalmodynamometry induced a mean IOP increase from 15.1 to 29.9 mmHg, causing a mean 34 ± 28% increase in CRF and 21 ± 25% decrease in CH. Magnitude of CH change did not differ between diagnostic groups or between eyes that did (n = 20) and did not (n = 95) develop new VF loss during the study period, nor was it related to rate of future VF progression. CONCLUSIONS Ophthalmodynamometry-induced IOP elevation resulted in significant acute changes in CH and CRF in this study; this suggests accounting for IOP may be important in clinical interpretation of these parameters. However, because the degree of CH change was not related to glaucoma or its progression, acute changes in CH and CRF do not seem to have a prognostic value for glaucoma.
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Changes to Corneal Topography and Biometrics after PRESERFLO Microshunt Surgery for Glaucoma. J Glaucoma 2021; 30:921-931. [PMID: 34255755 DOI: 10.1097/ijg.0000000000001912] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/23/2021] [Indexed: 11/25/2022]
Abstract
PRECISE Glaucoma surgery with the PRESERFLO Microshunt shows mild and transient changes in the corneal astigmatism, the corneal elevation and biometrics in the early postoperative period. The posterior corneal elevation tends to be higher in POAG. PURPOSE To determine the changes in the corneal keratometry, astigmatism and elevation, refraction, axial length and anterior chamber depth and volume after the implantation of the PRESERFLO Microshunt in patients with primary open angle glaucoma (POAG) in the early postoperative period. METHODS Patients diagnosed with primary open angle glaucoma (POAG) who underwent an ab-externo SIBS (poly(styrene-block-isobutylene-block-styrene) microshunt implantation were recruited. The central corneal thickness (CCT), the intraocular pressure (IOP), best corrected visual acuity (BCVA), refraction, biometrics and corneal topography with a Scheimpflug topographer were analyzed preoperatively and 24 hours, 1 week, 1 month and 3 months after surgery. RESULTS A total of 30 eyes of 29 patients were included. In 24 eyes the device was implanted as a standalone procedure and in 6 eyes it was combined with cataract surgery. The results were analyzed separately. The IOP decreased from 21.8±5.2 and 16.5±1.5▒mmHg at baseline to 10.9±1.8 and 10.1±1.1mmHg at 3 months in the non-combined and combined groups (P<0.01). The anterior, posterior and total corneal astigmatism (ASA, PSA, TCA) increased in each group 0.4±0.3/ 0.2±1.0 D, 0.08±0.1/ 0.03±0.1 D and 0.4±0.3/ 0.2±0.9 D respectively at 3 months. The anterior and posterior corneal elevation (ACE max, ACE min, PCE max) increased on the first week (P=0.01) with no significant changes at 3 months in the non-combined group. The changes observed in the combined group were not significant. The axial length (AL) decreased 0.13±0.23 and 0.2±0.07▒mm in each group (P=0.01). There was a significant correlation between the IOP and the maximum elevation of the posterior surface of the cornea at the preoperative examination (r=0.93, P= 0.02). CONCLUSIONS The PRESERFLO Microshunt implant for glaucoma surgery induces mild and transient changes in corneal astigmatism, axial length and anterior chamber depth in the early post-operative period.
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Changes in Corneal Biomechanics and Glaucomatous Visual Field Loss. J Glaucoma 2021; 30:e246-e251. [PMID: 33596020 DOI: 10.1097/ijg.0000000000001819] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 01/25/2021] [Indexed: 11/25/2022]
Abstract
PRECIS A lower baseline corneal hysteresis and a decrease in corneal resistance factor (CRF) over time are associated with higher risk of visual field progression in glaucomatous and glaucoma suspect eyes. PURPOSE The aim was to investigate the longitudinal change in CRF and cornea hysteresis (CH) as risk factors for visual field progression. MATERIALS AND METHODS In this prospective observational cohort study, 72 eyes of 48 glaucoma or glaucoma suspect patients were followed for an average of 4.5 years. Baseline and follow-up CH and CRF measurements were performed with the Ocular Response Analyzer (Reichert Ophthalmic Instruments Inc., Depew, N.Y.). Evaluation of rates of visual field change during follow-up was performed using visual field mean deviation. Univariable and multivariable linear mixed models assessed the relationship of visual field progression with baseline CRF and CH as well as with changes in CRF and CH. RESULTS The mean baseline CH was 9.0 (95% confidence interval: 8.6-9.4) mm Hg and the mean baseline CRF was 9.3 (95% confidence interval: 8.8-9.9) mm Hg. There was no statistically significant difference in average CH and CRF measurements over time. In multivariable modeling adjusting for age, race, and mean intraocular pressure during follow-up, each 1 mm Hg lower in baseline CH and 1 mm Hg decrease in CRF over time were associated with a 0.12 (P=0.042) and 0.14 dB/year (P=0.007) faster rate of visual field mean deviation loss, respectively. Similar findings were found in glaucoma eyes but not found in glaucoma suspect eyes. CONCLUSION Visual field progression was associated with a lower baseline CH and a decrease in CRF over time. Assessment of corneal resistance and elasticity at baseline and during follow-up examinations should be considered to identify those eyes at highest risk of visual field progression.
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The Relationship Between Corvis ST Tonometry Parameters and Ocular Response Analyzer Corneal Hysteresis. J Glaucoma 2020; 29:479-484. [PMID: 32134829 DOI: 10.1097/ijg.0000000000001486] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PRECIS Corvis ST Tonometry and Ocular Response Analyzer (ORA) measurements were conducted in primary open-angle glaucoma and normative subjects. Many parameters were significantly correlated, however, the strengths were weak to moderate. PURPOSE Reichert ORA parameters are derived from pressure information following the application of air-jet, whereas detailed structural observation can be made using the Corneal Visualization Scheimpflug Technology instrument (CST). The purpose of the study was to investigate the association between CST measurements and ORA measured corneal hysteresis (CH). METHODS Measurements of CST, ORA, axial length, average corneal curvature, central corneal thickness (CCT) and intraocular pressure with Goldmann applanation tonometry were carried out in 104 eyes of 104 patients with primary open-angle glaucoma and 35 eyes from normative subjects. The association between CST and ORA parameters was assessed using linear regression analysis, with model selection based on the second order bias corrected Akaike Information Criterion index. RESULTS Deformation amplitude ratio (corneal softness, R=-0.51), SP A1 (corneal stiffness, R=0.41), and Inverse Radius (integrated area under the curve of the inverse concave radius, R=-0.44) were significantly correlated with CH (P <0.05). The optimal model to explain CH using CST measurements was given by: CH=-76.3+4.6×A1 time (applanation time in the corneal inward movement)+1.9×A2 time (second applanation time in the corneal outward movement) + 3.1 × highest concavity deformation amplitude (magnitude of movement of the corneal apex from before deformation to its highest concavity) + 0.016×CCT (R=0.67; P<0.001). CONCLUSIONS CST parameters are significant, but weakly or moderately, related to ORA measured CH.
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Zhu R, Zheng X, Guo L, Zhao Y, Wang Y, Wu J, Yu AY, Wang J, Bao F, Elsheikh A. Biomechanical Effects of Two Forms of PGF2α on Ex-vivo Rabbit Cornea. Curr Eye Res 2020; 46:452-460. [PMID: 32795212 DOI: 10.1080/02713683.2020.1805771] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate the biomechanical effects of two synthetic prostaglandin F2α analogues (PGF2α), namely Travoprost and Tafluprost, on the ex-vivo rabbit cornea. MATERIALS AND METHODS Ninety-six eyes of 48 Japanese white rabbits were divided into 3 equal groups randomly; the Travoprost treated group (Tra), the Tafluprost treated group (Taf) and the control group (Co). Eyes in Tra and Taf groups were preserved in storage medium for 10 days with 1:10 Travoprost and Tafluprost diluents, respectively; while the Co eyes were preserved in a similar but PGF2α-free medium. Twenty-four corneas of each group were tested under inflation conditions with up to 30 mmHg posterior pressure. The pressure-deformation data obtained experimentally were used in an inverse analysis process to derive the stress-strain behavior of the tissue, using which the tangent modulus, a direct measure of the tissue's material stiffness, was calculated. The remaining eight specimens of each group were analyzed using electron microscopy for fibril diameter and interfibrillar spacing. RESULTS Although the central corneal thickness increased significantly in the three groups after storage (p < .01), it was similar in all groups both before (p = .598) and after storage (p = .181). After treatment with Travoprost and Tafluprost, the corneas exhibited lower tangent modulus (by 29.2% and 29.8%, respectively, at 6 kPa stress) and larger stromal interfibril spacing (by 21.9% and 23.6%) compared with the control group. There was no significant change in fibril diameter with either Travoprost or Tafluprost treatment (p = .769). CONCLUSIONS The results demonstrated significant reductions in tangent modulus and increases in interfibrillar spacing, which were of similar magnitudes, with the application of two different forms of PGF2α.
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Affiliation(s)
- Rong Zhu
- Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - XiaoBo Zheng
- Eye Hospital, Wenzhou Medical University, Wenzhou, China.,The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, China
| | - LiLi Guo
- Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - YiPing Zhao
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China
| | - Yuan Wang
- Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jie Wu
- Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - AYong Yu
- Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - JunJie Wang
- Eye Hospital, Wenzhou Medical University, Wenzhou, China.,The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, China
| | - FangJun Bao
- Eye Hospital, Wenzhou Medical University, Wenzhou, China.,The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, China
| | - Ahmed Elsheikh
- School of Engineering, University of Liverpool, Liverpool, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.,Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China
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Comparison of Biomechanically Corrected Intraocular Pressure Obtained by Corvis ST and Goldmann Applanation Tonometry in Patients With Open-angle Glaucoma and Ocular Hypertension. J Glaucoma 2020; 28:922-928. [PMID: 31453898 DOI: 10.1097/ijg.0000000000001348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PRECIS Biomechanically corrected intraocular pressure (bIOP) measurements provided by the new Corvis ST (CST) were higher than measurements obtained with Goldman applanation tonometry (GAT) in eyes with ocular hypertension (OHT) or open-angle glaucoma (OAG). PURPOSE To compare bIOP obtained with a new version of CST with GAT measurements in patients with OAG and OHT, and to identify factors affecting IOP measurement differences between these methods. METHODS A total of 122 eyes with OAG or OHT were enrolled. Sixty eyes were treated with prostaglandin analogs (PGA) and 62 eyes with selective laser trabeculoplasty (SLT). IOP was measured with CST, followed by GAT. Central corneal thickness (CCT) was measured with ultrasound pachymetry. Measurements obtained with these 2 approaches were compared. RESULTS The overall mean IOP was 15.2±3.0 mm Hg and 14.1±3.2 mm Hg with the CST and GAT, respectively (r=0.74; P<0.0001). There was a 1.17 mm Hg bias between tonometers, with 95% limits of agreement of -2.66 to 5.01 mm Hg. According to multivariate regression analysis, differences between bIOP and GAT-IOP were associated with CCT (P=0.001) and age (P=0.007) in the PGA group, but only with CCT in the SLT group (P=0.002). bIOP and GAT-IOP values were influenced by age (PGA: P=0.014; SLT: P=0.006) and CCT (PGA: P=0.007; SLT: P=0.032), respectively. CONCLUSIONS BIOP values were higher and less affected by CCT than GAT-IOP values in eyes with OAG and OHT. However, these measurements may not be interchangeable in the clinic.
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Radcliffe NM, Tracer N, De Moraes CGV, Tello C, Liebmann JM, Ritch R. Relationship between optic disc hemorrhage and corneal hysteresis. Can J Ophthalmol 2019; 55:239-244. [PMID: 31879066 DOI: 10.1016/j.jcjo.2019.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 10/16/2019] [Accepted: 10/24/2019] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the relationship between optic disc hemorrhage (DH) and corneal hysteresis (CH). METHODS Consecutive patients with prior or current photographic evidence of unilateral DH who had undergone CH measurement with the Ocular Response Analyzer (ORA; Reichert, Buffalo, NY) were enrolled. Eyes with a history of corneal disease, refractive surgery, or bilateral DH were excluded. Central corneal thickness (CCT), visual field data, 5 consecutive previous intraocular pressures (IOPs), and maximum documented peak IOP were obtained by chart review. Vertical cup-to-disc ratio (VCDR), the presence of neuroretinal rim notching, number of clock hours of beta zone parapapillary atrophy (ßPPA), and eye with greater ßPPA width were determined from photographs by 2 masked expert examiners. RESULTS We identified and analyzed 49 patients with photographically documented unilateral DH. Compared to fellow non-DH eyes, eyes with DH had lower CH (8.7 ± 1.9 vs 9.2 ± 1.7; p = 0.002), higher IOP (15.6 ± 3.6 vs 14.3 ± 4.1; p = 0.017), and greater VCDR (0.79 ± 0.13 vs 0.68 ± 0.23; p < 0.001), but were similar with respect to CCT, ßPPA extent, rim notching, peak IOP, and visual field damage (all p > 0.05). Using multivariate conditional logistic regression analysis, only CH (p = 0.012) and VCDR (p = 0.004) predicted the laterality of the DH. CONCLUSIONS Lower CH and greater VCDR are independently associated with DH. This suggests that CH may be a structural biomarker for an abnormality of the optic nerve complex that may be associated with progressive glaucoma. Eyes in which DH were detected had lower CH.
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Affiliation(s)
| | | | | | - Celso Tello
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, NY
| | - Jeffrey M Liebmann
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, NY
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Sorkhabi R, Najafzadeh F, Sadeghi A, Ahoor M, Mahdavifard A. Corneal biomechanical changes after trabeculectomy with mitomycin C in primary open-angle glaucoma and pseudoexfoliation glaucoma. Int Ophthalmol 2019; 39:2741-2748. [PMID: 31134423 DOI: 10.1007/s10792-019-01118-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 05/22/2019] [Indexed: 11/24/2022]
Abstract
PURPOSE This study aimed to examine the effect of trabeculectomy with mitomycin C on corneal biomechanical characteristics in PEXG and POAG patients. METHODS In this prospective comparative case series study, 32 glaucoma patients of whom 17 patients were suffering from PEXG and 15 patients from POAG were enrolled. All patients underwent complete ocular examination, CCT using ultrasound pachymetry and corneal biomechanical study using ORA. The patients were hospitalized, and trabeculectomy surgery with mitomycin was done. Three months after surgery, patients were examined and ORA was obtained again. RESULTS The mean CH in patients with PEXG was lower compared to patients with POAG (5.66 ± 1.13, 7.49 ± 0.88, respectively) before surgery, which had a statistically significant difference (P < 0.001). CRF in patients with PEXG was significantly lower compared to patients with POAG (8.19 ± 1.48 vs. 9.35 ± 1.60, respectively) before surgery, with P = 0.049. CH remarkably increased and reached 6.69 ± 0.78 (P < 0.001) in the PEXG group after TBX + MMC surgery. CH increased in the POAG group after TBX + MIC surgery and reached 8.23 ± 1.09, which was statistically significant (P = 0.001). There was a significant relationship between CH and IOPg changes in both PEXG and POAG groups (P < 0.001 and P = 0.01, respectively). Although TBX + MMC surgery changed the amount of CH in PEXG and POAG groups, no significant difference was shown in the parameters between the two groups comparing the CH changes (P = 0.33). CONCLUSION According to the results of this study, the biomechanical characteristics of cornea, particularly CH, shows certain changes following surgery and is increased, reflecting the dynamic nature of these parameters. Our knowledge of the biomechanical changes after glaucoma surgery can help us better understand the pathophysiology of glaucoma diseases and make the right decisions for follow-up of the patients.
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Affiliation(s)
- Rana Sorkhabi
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Farhad Najafzadeh
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Ali Sadeghi
- Eye Research Center, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mohamadhosein Ahoor
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Mahdavifard
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran
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Salouti R, Alishiri AA, Gharebaghi R, Naderi M, Jadidi K, Shojaei-Baghini A, Talebnejad M, Nasiri Z, Hosseini S, Heidary F. Comparison among Ocular Response Analyzer, Corvis ST and Goldmann applanation tonometry in healthy children. Int J Ophthalmol 2018; 11:1330-1336. [PMID: 30140637 DOI: 10.18240/ijo.2018.08.13] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/23/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To explore the relationship between different parameters of Ocular Response Analyzer (ORA) and Corvis ST (CST) in a sample of healthy Iranian school-aged children and the relationship between parameters of these 2 instruments against intraocular pressure (IOP), measured by the Goldmann applanation tonometer (GAT-IOP), age and gender, and find possible correlation between ORA and CST with GAT. METHODS This cross-sectional study included 90 healthy children. A general interview and complete eye examination were performed. Following successful GAT-IOP measurement, ORA and CST were conducted. The CST parameters were A 1/2 length (A1L, A2L), A 1/2 velocity (A1V, A2V), highest concavity deformation amplitude (HCDA), radius of curvature (RoC), peak distance (PD), central corneal thickness (CCT) and IOP. The ORA parameters were corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated IOP (IOP-G) and corneal compensated IOP (IOP-CC). Extracted data was analyzed using the Statistical Package for Social Science software. RESULTS Totally 39 males with age of 9.08±1.60 (6-12)y and 51 females with age of 8.96±1.55 (6-13)y were included. Many CST parameters were significantly correlated with CH, CRF, IOP-G and IOP-CC. Some CST parameters had a significant correlation with GAT-IOP, including IOP-CST in both eyes and HCDA, A2L, PD, and RoC in the left eye, but none with age, except A2L in the right eye. The CRF measurement showed a significant correlation with GAT-IOP in both eyes and CH in the right eye, yet, none with age. Among all CST and ORA parameters, CCT-CST in both eyes and A1L in right eye had a significant correlation with gender, although this was a negligible negative correlation. Comparison of mean IOP values by different devices showed a significantly highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Also, IOP-G versus IOP-CST significantly had the lowest IOP overestimation among others. Overall, either low positive correlation or negligible correlation was found between IOP measurements by 3 instruments. CONCLUSION The study finds the highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Overall, either low positive correlation or negligible correlation is found between IOP measurements by the 3 instruments.
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Affiliation(s)
- Ramin Salouti
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz 7134814336, Iran
| | - Ali Agha Alishiri
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Reza Gharebaghi
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz 7134814336, Iran
| | - Mostafa Naderi
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Khosrow Jadidi
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Ahmad Shojaei-Baghini
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Mohammadreza Talebnejad
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz 7134814336, Iran
| | - Zahra Nasiri
- Faculty of Mathematical Sciences, Tarbiat Modares University, Tehran 141551856, Iran
| | - Seyedmorteza Hosseini
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Fatemeh Heidary
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences; Immunoregulation Research Center, Shahed University, Tehran 141551856, Iran
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Sayed MS, Lee RK. Corneal Biomechanical Properties and Their Role in Glaucoma Diagnosis and Management. Int Ophthalmol Clin 2018; 58:35-49. [PMID: 29870409 DOI: 10.1097/iio.0000000000000233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lagrou LM, Gilbert J, Hannibal M, Caird MS, Thomas I, Moroi SE, Bohnsack BL. Altered corneal biomechanical properties in children with osteogenesis imperfecta. J AAPOS 2018; 22:183-187.e1. [PMID: 29635034 DOI: 10.1016/j.jaapos.2017.12.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 12/27/2017] [Accepted: 12/29/2017] [Indexed: 10/17/2022]
Abstract
PURPOSE To evaluate biomechanical corneal properties in children with osteogenesis imperfecta (OI). METHODS A prospective, observational, case-control study was conducted on children 6-19 years of age diagnosed with OI. Patients with OI and healthy control subjects underwent complete ophthalmic examinations. Additional tests included Ocular Response Analyzer (ORA) and ultrasonic pachymetry. Primary outcomes were central corneal thickness (CCT), corneal hysteresis (CH), and corneal resistance factor (CRF). Intraocular pressure (IOP) was measured directly by either iCare or Goldmann applanation and indirectly by the ORA (Goldmann-correlated and corneal-compensated IOP). Statistically significant differences between OI and control groups were determined using independent samples t test. RESULTS A total of 10 of 18 OI cases (mean age, 13 ± 4.37 years; 8 males) and 30 controls (mean age, 12.76 ± 2.62 years; 16 males) were able to complete the corneal biomechanics and pachymetry testing. Children with OI had decreased CH (8.5 ± 1.0 mm Hg vs 11.6 ± 1.2 mm Hg [P < 0.001]), CRF (9.0 ± 1.9 mm Hg vs 11.5 ± 1.5 [P < 0.001]) and CCT (449.8 ± 30.8 μm vs 568 ± 47.6 μm [P < 0.001]) compared to controls. The corneal-compensated IOP was significantly higher in OI cases (18.8 ± 3.1 mm Hg) than in controls (15.0 ± 1.6 mm Hg, P < 0.004), but there was no significant difference in Goldmann-correlated IOP (16.3 ± 4.2 mm Hg vs 15.8 ± 2.2 mm Hg). CONCLUSIONS Collagen defects in OI alter corneal structure and biomechanics. Children with OI have decreased CH, CRF, and CCT, resulting in IOPs that are likely higher than measured by tonometry. These corneal alterations are present at a young age in OI. Affected individuals should be routinely screened for glaucoma and corneal pathologies.
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Affiliation(s)
- Lisa M Lagrou
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Jesse Gilbert
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Mark Hannibal
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Michelle S Caird
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Inas Thomas
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Sayoko E Moroi
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan
| | - Brenda L Bohnsack
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan.
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Chen M, Kueny L, Schwartz AL. The role of corneal hysteresis during the evaluation of patients with possible normal-tension glaucoma. Clin Ophthalmol 2018; 12:555-559. [PMID: 29606853 PMCID: PMC5868619 DOI: 10.2147/opth.s161675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose There are multiple reports of the role of corneal hysteresis (CH) as an independent risk factor for the diagnosis and risk of progression of normal-tension glaucoma (NTG). Our study measured CH with the Ocular Response Analyzer (ORA) in patients with intraocular pressure (IOP) <21 mmHg to investigate if a low CH would identify NTG in this Asian-based practice. Methods This was a prospective cross-sectional study of patients who underwent routine eye examination during 2016 in a private practice in Honolulu, Hawaii, where most patients are Asian. Inclusion criteria are: 1) ≥65 years 2) IOP <21 (compensated IOP by ORA), and 3) CH values <10 using ORA as measured by a single experienced technician. Exclusion criteria are: 1) sight-limiting ocular or corneal disease that would preclude accurate measurements for the purposes of the study. 2) Any patient who had difficulty in being tested with the ORA. 3) Patients who had any history of any type of glaucoma. All patients that met the inclusion criteria underwent fundus photography to measure cup-to-disc ratio and cup-to-disc asymmetry and also had central corneal thickness measured. Thickness of the retina nerve fiber layer was measured by ocular coherence tomography. The eyes with an average retina nerve fiber layer thickness less than 80 μm were classified as possible NTG and were scheduled for a visual field test. The field examination was considered valid only if the fixation, false positives, and false negatives were within the acceptable range. Patient demographics and data on preexisting diseases were collected including age, sex, coexisting medical conditions, and previous intraocular surgery. Those with thinning of retina nerve fiber layer on optical coherence tomography had a Humphrey visual field test to confirm the diagnosis of glaucoma. Results Seventy-six eyes of 46 patients that met the eligibility criteria were included in the study. Twenty-one previously undiagnosed eyes were confirmed as having NTG, which corresponds to an incidence of 27.6%. Conclusion CH measurement is a valuable test to assist in early diagnosis of NTG, especially in the elderly Asian population. With an established diagnosis, aggressive early treatments medically or surgically to further lower IOP can prevent irreversible blindness, which can severely impact the patient’s family and socioeconomic status.
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Affiliation(s)
- Ming Chen
- Department of Surgery, Division of Ophthalmology, University of Hawaii, Honolulu, HI, USA
| | - Laura Kueny
- Department of Ophthalmology, Georgetown University, Washington, DC, USA
| | - Arthur L Schwartz
- Department of Ophthalmology, Georgetown University, Washington, DC, USA
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Susanna CN, Diniz-Filho A, Daga FB, Susanna BN, Zhu F, Ogata NG, Medeiros FA. A Prospective Longitudinal Study to Investigate Corneal Hysteresis as a Risk Factor for Predicting Development of Glaucoma. Am J Ophthalmol 2018; 187:148-152. [PMID: 29305310 DOI: 10.1016/j.ajo.2017.12.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/10/2017] [Accepted: 12/19/2017] [Indexed: 11/17/2022]
Abstract
PURPOSE To investigate the role of corneal hysteresis (CH) as a risk factor for development of glaucoma. DESIGN Prospective observational cohort study. METHODS Two hundred and eighty-seven eyes of 199 patients suspected of having glaucoma were followed for an average of 3.9 ± 1.8 years. All eyes had normal visual fields at baseline. Development of glaucoma was defined as occurrence of 3 consecutive abnormal standard automated perimetry tests during follow-up, defined as pattern standard deviation (PSD) < 5%, and/or Glaucoma Hemifield Test outside normal limits. Measurements of CH were acquired at baseline using the Ocular Response Analyzer (ORA). Univariable and multivariable Cox regression models were used to investigate baseline factors associated with development of visual field loss over time. RESULTS Fifty-four (19%) eyes developed repeatable visual field defects during follow-up. Measurements of CH at baseline were significantly lower in patients who developed glaucoma vs those who did not (9.5 ± 1.5 mm Hg vs 10.2 ± 2.0 mm Hg; P = .012). Each 1-mm Hg lower CH was associated with an increase of 21% in the risk of developing glaucoma during follow-up (95% confidence interval [CI]: 1.04-1.41; P = .013). In a multivariable model adjusting for age, intraocular pressure, central corneal thickness, PSD, and treatment, CH was still predictive of development of glaucoma (hazard ratio = 1.20; 95% CI: 1.01-1.42; P = .040). CONCLUSION Baseline lower CH measurements were significantly associated with increased risk of developing glaucomatous visual field defects over time. The prospective longitudinal design of this study supports a role of CH as a risk factor for developing glaucoma.
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Affiliation(s)
- Carolina N Susanna
- Duke Eye Center and Department of Ophthalmology, Duke University, Durham, North Carolina; Department of Ophthalmology, University of California San Diego, La Jolla, California
| | - Alberto Diniz-Filho
- Department of Ophthalmology, University of California San Diego, La Jolla, California
| | - Fábio B Daga
- Duke Eye Center and Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Bianca N Susanna
- Duke Eye Center and Department of Ophthalmology, Duke University, Durham, North Carolina; Department of Ophthalmology, University of California San Diego, La Jolla, California
| | - Feilin Zhu
- Department of Ophthalmology, University of California San Diego, La Jolla, California
| | - Nara G Ogata
- Duke Eye Center and Department of Ophthalmology, Duke University, Durham, North Carolina
| | - Felipe A Medeiros
- Duke Eye Center and Department of Ophthalmology, Duke University, Durham, North Carolina; Department of Ophthalmology, University of California San Diego, La Jolla, California.
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Tonometers-which one should I use? Eye (Lond) 2018; 32:931-937. [PMID: 29456251 DOI: 10.1038/s41433-018-0040-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 11/08/2022] Open
Abstract
Although several factors are known to play a role in the development and progression of glaucoma, intraocular pressure (IOP) remains the only modifiable risk factor. Medical and surgical treatments for glaucoma both aim to reduce IOP to minimize disease progression. Tonometry is therefore an essential element of the ophthalmological exam. There are several types of tonometers available currently. These range from well-established instruments that have been in clinical use for decades to new devices, which are the result of recent technological advances. The various instruments have advantages and disadvantages that affect their suitability for a given setting, purpose, and patient population. In this review, we aim to describe the most commonly available tonometers today along with their advantages, disadvantages, and applicability.
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Aoki S, Murata H, Matsuura M, Fujino Y, Nakakura S, Nakao Y, Kiuchi Y, Asaoka R. The effect of air pulse-driven whole eye motion on the association between corneal hysteresis and glaucomatous visual field progression. Sci Rep 2018; 8:2969. [PMID: 29445204 PMCID: PMC5813173 DOI: 10.1038/s41598-018-21424-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 02/05/2018] [Indexed: 11/30/2022] Open
Abstract
Corneal hysteresis (CH) measured with Ocular Response Analyzer (Reichert: ORA) has been reported to be closely related to the glaucomatous visual field (VF) progression. The air pulse applied to an eye not only induces corneal deformation, but also whole eye motion (WEM), which may result in an inaccurate measurement of CH. Here we investigated the influence of air pulse-driven WEM measured with the Corivs ST (CST®, OCULUS) on the relationship between CH and VF progression in primary open angle-glaucoma patients. Using the CST parameters of the maximal WEM displacement (WEM-d) and the time to reach that displacement (WEM-t), the eyes were classified into subgroups (WEM-d low- and high-group, and WEM-t short- and long-group). For the whole population and all subgroups, the optimal linear mixed model to describe mean of total deviation (mTD) progression rate with eight reliable VFs was selected from all combinations of seven parameters including CH. As a result, optimal models for the mTD progression rate included CH in the whole population, the WEM-d low- group and the WEM-t short-group, but not in the WEM-d high-group and the WEM-t long-group. Our findings indicated association between CH and glaucomatous progression can be weakened because of large WEM.
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Affiliation(s)
- Shuichiro Aoki
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Murata
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Masato Matsuura
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan.,Department of Rehabilitation, Orthopic and Visual Science, School of Allied Health Sciences, Kitasato University, Tokyo, Kanagawa, Japan
| | - Yuri Fujino
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Shunsuke Nakakura
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, Japan
| | - Yoshitaka Nakao
- Department of Ophthalmology and Visual Sciences, Hiroshima University, Higashihiroshima, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Sciences, Hiroshima University, Higashihiroshima, Japan
| | - Ryo Asaoka
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan.
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Hussnain SA, Kovacs KD, Warren JL, Teng CC. Corneal hysteresis and anterior segment optical coherence tomography anatomical parameters in primary angle closure suspects. Clin Exp Ophthalmol 2018; 46:468-472. [PMID: 29251401 DOI: 10.1111/ceo.13135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/20/2017] [Accepted: 12/05/2017] [Indexed: 11/29/2022]
Abstract
IMPORTANCE Corneal hysteresis (CH) is a dynamic marker of structural and functional changes in the cornea associated with intraocular pressure (IOP) and central corneal thickness, but its utility in assessing primary angle closure suspects (PACS) has not been fully elucidated. BACKGROUND This study assesses if anterior segment measurements correlate with CH in PACS patients. DESIGN IRB-approved retrospective review of imaging and records at a university practice. PARTICIPANTS Sixty-three eyes from 37 patients diagnosed as PACS, without other ocular pathology. METHODS Every eye underwent measurements including: ocular response analyzer (ORA), anterior segment optical coherence tomography (OCT) and a clinical evaluation. ORA measurements were correlated with other anatomic parameters using a mixed effects multivariable linear regression framework. MAIN OUTCOME MEASURES ORA measurements included: CH, corneal resistance factor, Goldmann IOP (IOPg ) and corneal compensated IOP (IOPcc ). Anterior segment OCT measurements included: central corneal thickness (CCTOCT ), nasal and temporal peripheral corneal thicknesses (PCT1 and PCT2), anterior chamber depth (ACD), nasal angle to temporal angle distance (ATA) and temporal and nasal angle measurements. Clinical measurements included: central corneal thickness via pachymetry, IOP measured by Goldmann applanation, axial length by A-scan ultrasound and spherical equivalent. RESULTS CH was negatively correlated with IOPcc, and ACD CH was positively correlated with CCTOCT , CCTp , CRF, PCT1 and PCT2. Females were found to have lower CH. In multivariable regression controlling for gender, CCT, PCT, IOP and ACD, no correlation was seen between CH and anatomic measurements. CONCLUSIONS AND RELEVANCE CH values in PACS do not correlate with anterior segment anatomy.
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Affiliation(s)
- Syed Amal Hussnain
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, Connecticut, USA
| | - Kyle D Kovacs
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, Connecticut, USA
| | - Joshua L Warren
- Department of Biostatistics, Yale School of Public Health, New Haven, Connecticut, USA
| | - Christopher C Teng
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, Connecticut, USA
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Evaluation of Corneal Deformation Parameters Provided by the Corvis ST Tonometer After Trabeculectomy. J Glaucoma 2017; 26:166-172. [PMID: 27875486 DOI: 10.1097/ijg.0000000000000590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aims of this study were to evaluate how the corneal deformation parameters provided by the Corvis ST tonometer (CST) were influenced by pressure-lowering ocular surgery, and to determine the correlations of intraocular pressure (IOP) and axial length (AL) with CST corneal deformation parameters. METHODS This prospective 1-month study enrolled 22 subjects (22 eyes) who underwent trabeculectomy combined with mitomycin C. The corneal deformation parameters were measured using the CST. IOP was measured before and after surgery by a Goldmann applanation tonometer and the CST. The central corneal thickness and AL were also recorded. The correlations of the corneal deformation parameters with central corneal thickness, AL, and IOP changes were determined by linear regression analysis. RESULTS IOP decreased significantly after surgery. AL was significantly shorter at 1 week after surgery. There were significant changes in the CST parameters time 1, velocity 1, velocity 2, peak distance highest concavity, and deformation amplitude highest concavity at 1 week and 1 month after surgery and in time highest concavity at 1 week after surgery. The change in time 1 was significantly correlated with preoperative IOP and the IOP reductions, and was positively correlated with the decrease in AL at 1 week. The increase in velocity 1 was negatively correlated with preoperative IOP, and IOP reductions. The change in time highest concavity was negatively correlated with IOP before surgery and the decrease in IOP at 1 week. CONCLUSION CST is a good choice for measuring IOP, especially when aiming for normalization of IOP after glaucoma surgery.
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Corneal Biomechanical Changes After Trabeculectomy and the Impact on Intraocular Pressure Measurement. J Glaucoma 2017; 26:278-282. [PMID: 27977478 DOI: 10.1097/ijg.0000000000000595] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate corneal biomechanical changes induced by trabeculectomy and their impact on intraocular pressure (IOP) measurements. MATERIALS AND METHODS In total, 35 eyes of 35 consecutive glaucoma patients undergoing first-time trabeculectomy with mitomycin C were enrolled in this prospective interventional case series. Goldmann applanation tonometry (GAT) IOP, central corneal thickness, axial length, and Ocular Response Analyzer measurements [Goldmann-correlated IOP (IOPg), corneal-compensated IOP (IOPcc), corneal hysteresis (CH), and corneal resistance factor (CRF)] were assessed before and 6 months after uncomplicated trabeculectomy. Linear mixed models were used to compare the parameters before and after surgery. RESULTS IOP, central corneal thickness, and axial length showed a strong correlation with CH and CRF preoperatively and postoperatively. After adjusting for these influencing factors, CH changed from 7.75±1.46 to 7.62±1.66 mm Hg (P=0.720) and CRF from 8.67±1.18 to 8.52±1.35 mm Hg (P=0.640) after trabeculectomy, but these changes were not statistically significant. IOP decreased statistically significantly with all IOP measurements (P=0.001). IOPcc was statistically significantly higher than GAT (4.82±5.24 mm Hg; P=0.001) and IOPg (2.92±1.74 mm Hg; P=0.001) preoperatively and postoperatively (GAT, 3.29±3.36 mm Hg; P=0.001; IOPg, 3.35±1.81 mm Hg; P=0.001). The difference between IOPcc and GAT (P=0.5) and IOPcc and IOPg (P=0.06) did not change significantly before or after trabeculectomy. CONCLUSIONS Despite a marked IOP reduction and a possible weakening of the ocular walls after trabeculectomy, corneal structural tissue properties are not altered, and therefore, the accuracy of IOP measurements is not changed postoperatively. It seems likely, however, that Goldmann-correlated IOP measurements are underestimated in glaucoma patients before and after surgery.
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Corneal Biomechanical Properties After Penetrating Keratoplasty or Deep Anterior Lamellar Keratoplasty Using the Ocular Response Analyzer: A Meta-Analysis. Cornea 2017; 36:310-316. [PMID: 28002108 DOI: 10.1097/ico.0000000000001113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE To evaluate the corneal biomechanical properties of patients who have undergone penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty (DALK) using the ocular response analyzer. METHODS Stata 13.0 SE was used for this meta-analysis. Studies in the literature that focused on corneal hysteresis (CH) or corneal resistance factor (CRF) after PK or DALK were retrieved by searching PubMed, Embase, Ovid, and Cochrane databases. We present the results as weighted mean difference (WMD) with a corresponding 95% confidence interval (CI). RESULTS Eight studies with a total of 750 eyes were included in the post-PK versus control group, and 4 studies with a total of 218 eyes were included in the post-DALK versus control group. The pooled results showed that CH and CRF were significantly reduced (P < 0.00001) for patients who have undergone PK (WMD = -1.16, 95% CI: -1.73 to -0.60 and WMD = -1.00, 95% CI: -1.61 to -0.40). No significant differences were found in both CH and CRF for patients who have undergone DALK (WMD = -0.27, 95% CI: -0.64 to -0.09 and WMD = -0.15, 95% CI: -0.53 to 0.23). CONCLUSIONS This meta-analysis suggested that both CH and CRF had better recovery after corneal transplantation with DALK than PK.
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Liu B, McNally S, Kilpatrick JI, Jarvis SP, O'Brien CJ. Aging and ocular tissue stiffness in glaucoma. Surv Ophthalmol 2017; 63:56-74. [PMID: 28666629 DOI: 10.1016/j.survophthal.2017.06.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 06/20/2017] [Accepted: 06/22/2017] [Indexed: 12/27/2022]
Abstract
Glaucoma is a progressive and chronic neurodegenerative disorder characterized by damage to the inner layers of the retina and deformation of the optic nerve head. The degeneration of retinal ganglion cells and their axons results in an irreversible loss of vision and is correlated with increasing age. Extracellular matrix changes related to natural aging generate a stiffer extracellular environment throughout the body. Altered age-associated ocular tissue stiffening plays a major role in a significant number of ophthalmic pathologies. In glaucoma, both the trabecular meshwork and the optic nerve head undergo extensive extracellular matrix remodeling, characterized by fibrotic changes associated with cellular and molecular events (including myofibroblast activation) that drive further tissue fibrosis and stiffening. Here, we review the literature concerning the role of age-related ocular stiffening in the trabecular meshwork, lamina cribrosa, sclera, cornea, retina, and Bruch membrane/choroid and discuss their potential role in glaucoma progression. Because both trabecular meshwork and lamina cribrosa cells are mechanosensitive, we then describe molecular mechanisms underlying tissue stiffening and cell mechanotransduction and how these cellular activities can drive further fibrotic changes within ocular tissues. An improved understanding of the interplay between age-related tissue stiffening and biological responses in the trabecular meshwork and optic nerve head could potentially lead to novel therapeutic strategies for glaucoma treatment.
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Affiliation(s)
- Baiyun Liu
- School of Physics, Conway Institute, University College Dublin, Dublin, Ireland; Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Sara McNally
- Department of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Jason I Kilpatrick
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Suzanne P Jarvis
- School of Physics, Conway Institute, University College Dublin, Dublin, Ireland; Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Colm J O'Brien
- Department of Ophthalmology, Mater Misericordiae University Hospital, Dublin, Ireland; School of Medicine and Medical Science, University College Dublin, Dublin, Ireland.
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Li BB, Cai Y, Pan YZ, Li M, Qiao RH, Fang Y, Tian T. Corneal Biomechanical Parameters and Asymmetric Visual Field Damage in Patients with Untreated Normal Tension Glaucoma. Chin Med J (Engl) 2017; 130:334-339. [PMID: 28139518 PMCID: PMC5308017 DOI: 10.4103/0366-6999.198920] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background: High intraocular pressure (IOP) and low central corneal thickness (CCT) are important validated risk factors for glaucoma, and some studies also have suggested that eyes with more deformable corneas may be in higher risk of the development and worsening of glaucoma. In the present study, we aimed to evaluate the association between corneal biomechanical parameters and asymmetric visual field (VF) damage using a Corvis-ST device in patients with untreated normal tension glaucoma (NTG). Methods: In this observational, cross-sectional study, 44 newly diagnosed NTG patients were enrolled. Of these, 31 had asymmetric VF damage, which was defined as a 5-point difference between the eyes according to the Advanced Glaucoma Intervention Study scoring system. Corneal biomechanical parameters were obtained using a Corvis-ST device, such as time from start until the first and second applanation is reached (time A1 and time A2, respectively), cord length of the first and second applanation (length A1 and length A2, respectively), corneal speed during the first and second applanation (velocity A1 and velocity A2, respectively), time from start until highest concavity is reached (time HC), maximum amplitude at the apex of highest concavity (def ampl HC), distance between the two peaks at highest concavity (peak dist HC), and central concave curvature at its highest concavity (radius HC). Results: Time A1 (7.19 ± 0.28 vs. 7.37 ± 0.41 ms, P = 0.010), length A1 (1.73 [1.70–1.76] vs. 1.78 [1.76–1.79] mm, P = 0.007), length A2 (1.58 [1.46–1.70] vs. 1.84 [1.76–1.92] mm, P < 0.001), peak dist HC (3.53 [3.08–4.00] vs. 4.33 [3.92–4.74] mm, P = 0.010), and radius HC (6.20 ± 0.69 vs. 6.59 ± 1.18 mm, P = 0.032) were significantly lower in the worse eyes than in the better eyes, whereas velocity A1 and def ampl HC were significantly higher (0.156 [0.149–0.163] vs. 0.145 [0.138–0.152] m/s, P = 0.002 and 1.19 ± 0.13 vs. 1.15 ± 0.13 mm, P = 0.005, respectively). There was no significant difference in time A2, velocity A2, and time HC between the two groups. In addition, no difference was observed in IOP, CCT, and axial length. In the univariate and multivariate analyses, some of the Corvis-ST parameters, including time A1 and def ampl HC, were correlated with known risk factors for glaucoma, and there was also a significant positive correlation between def ampl HC and age. Conclusions: There were differences in dynamic corneal response parameters but not IOP or CCT between the paired eyes of NTG patients with asymmetric VF damage. We suggest that the shape of the cornea is more easily altered in the worse eyes of asymmetric NTG patients.
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Affiliation(s)
- Bai-Bing Li
- Department of Ophthalmology, Peking University First Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100034, China
| | - Yu Cai
- Department of Ophthalmology, Peking University First Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100034, China
| | - Ying-Zi Pan
- Department of Ophthalmology, Peking University First Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100034, China
| | - Mei Li
- Department of Ophthalmology, Peking University First Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100034, China
| | - Rong-Hua Qiao
- Department of Ophthalmology, Beijing Tsinghua Changgung Hospital, Beijing 102218, China
| | - Yuan Fang
- Department of Ophthalmology, Peking University First Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100034, China
| | - Tian Tian
- Department of Ophthalmology, Peking University First Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100034, China
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Refai TA, Hassanin OA. Refinement of Intraocular Pressure Measurements made by Ocular Response Analyzer following Laser in Situ Keratomileusis using M2 90 Moria Microkeratome for Egyptian Myopic and Astigmatic Patients. Electron Physician 2017; 8:3429-3433. [PMID: 28163860 PMCID: PMC5279978 DOI: 10.19082/3429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/17/2016] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION The Goldmann applanation tonometer readings were noted to be markedly reduced after Lasik surgery using a thin flap technique which is widely used nowadays, to correct a wide range of myopia and astigmatism. The Ocular Response Analyzer (ORA) is considered one of the important tools for refinement of Intraocular Pressure (IOP) measurements. The aim of this study is to evaluate and refine ORA measurements for IOP changes post- M2 90 Moria microkeratome Lasik procedure for Egyptian myopic and astigmatic patients trying to aid in glaucoma diagnosis and management. METHODS Thirty-five eyes of nineteen Egyptian patients with myopia or myopic astigmatism who had undergone Lasik procedure using M2 90 Moria microkeratome were included in this consecutive case series study. All cases were subjected to full ophthalmological examination including uncorrected and best corrected visual acuity, refraction, slit lamp examination, Scheimpflug imaging and ORA (Reichert Ophthalmic Instruments, Inc., Buffalo, NY, USA). The refractive errors were measured using an auto refractometer and were confirmed by trial. For the ocular response analyzer, the Goldmann-correlated IOP measurement (IOPg) which simulates IOP measured by Goldmann tonometer and the Corneal-Compensated Intraocular Pressure (IOPcc) that takes corneal biomechanical properties into consideration were reported as well as the Corneal Hysteresis (CH) and the Corneal Resistance Factor (CRF). Cases were examined preoperatively and again about one month after Lasik, after stabilization of eye condition. The collected data were tabulated and analysed with the suitable statistical methods. The mean values and standard deviation were calculated for quantitative data. Comparison tests (t-test) and correlation tests (Pearson) were also performed. RESULTS In our study, involving M2 90 Moria microkeratome Lasik procedure, a highly significant post-Lasik reduction in IOPg (t-test = 8.62 (p<0.01), and a statistically significant reduction in IOPcc (t-test = 3.37 (p<0.05) by ocular response analyzer. The average post-Lasik reduction in IOP in mmHg was 4.84±2.82 for IOPg and 2.23±3.51for IOPcc. A statistically significant correlation (p<0.05) existed between post-Lasik reduction of IOPg and ablation depth as well as preoperative spherical equivalent. A non-significant correlation existed between post-Lasik reduction of IOPcc and both of ablation depth and preoperative spherical equivalent. CONCLUSIONS Following Lasik procedure using M2 90 Moria microkeratome, the IOPcc values by ORA were closer to the preoperative values than the IOPg values and the reduction of IOPcc values was not affected by ablation depth (i.e. preoperative spherical equivalent). Therefore, it is advisable to use the IOPcc values by ORA when evaluating post-Lasik patients for glaucoma diagnosis and management, but with the addition of the average value for post-Lasik reduction which in the study was 2.23±3.51mmHg.
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Affiliation(s)
- Tamer Adel Refai
- Refractive Unit, Ophthalmology Department, Research Institute of Ophthalmology, Giza, Egypt
| | - Olfat A Hassanin
- Refractive Unit, Ophthalmology Department, Research Institute of Ophthalmology, Giza, Egypt
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Zimmermann M, Pitz S, Schmidtmann I, Pfeiffer N, Wasielica-Poslednik J. Tonographic Effect of Ocular Response Analyzer in Comparison to Goldmann Applanation Tonometry. PLoS One 2017; 12:e0169438. [PMID: 28068365 PMCID: PMC5221819 DOI: 10.1371/journal.pone.0169438] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 12/06/2016] [Indexed: 11/29/2022] Open
Abstract
Aims The tonographic effect is a phenomenon of intraocular pressure (IOP) reduction following repeated tonometry. This study examines whether the tonographic effect occurs following IOP measurement performed with Ocular Response Analyzer (ORA). Methods Both eyes of 31 glaucoma patients and 35 healthy controls underwent nine IOP-measurements performed with GAT and ORA. The number of GAT and ORA measurements performed on each eye differed depending on the randomly allocated investigation scheme. Central corneal thickness (CCT), anterior chamber volume (ACV) and anterior chamber depth (ACD) were assessed with Pentacam before and after the repeated GAT/ORA measurements. Results There was no statistically significant tonographic effect for IOP readings obtained by the ORA: corneal compensated intraocular pressure (IOPcc) (-0.11 ± 3.06 mmHg, p = 0.843 in patients and -0.71 ± 3.28 mmHg, p = 0.208 for controls) and Goldmann-correlated intraocular pressure (IOPg) (-0.31 ± 2.38 mmHg, p = 0.469 in patients and -0.31 ± 2.37 mmHg, p = 0.441 in controls) measured with ORA. There was a significant IOP reduction from the first to the second GAT measurement, i.e. tonographic effect (-0.55 ± 2.00 mmHg, p = 0.138 in patients and -1.15 ± 1.52 mmHg, p < 0.001 in controls). CCT, corneal hysteresis (CH) and corneal resistance factor (CRF) were lower in glaucoma patients. The repeated IOP measurements resulted in an increase of CCT in all subjects (but no change of ACV and ACD). The tonographic effect of GAT correlated with CCT in glaucoma patients (r = 0.37). Conclusion In contrast to GAT, repeated ORA measurements do not result in the tonographic effect. Repeated IOP measurements resulted in an increase of central corneal thickness, but did not influence the volume and depth of anterior chamber.
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Affiliation(s)
- Martin Zimmermann
- Department of Ophthalmology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- * E-mail:
| | - Susanne Pitz
- Department of Ophthalmology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Irene Schmidtmann
- Institute for Medical Biostatistics, Epidemiology and Informatics (IMBEI), University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Norbert Pfeiffer
- Department of Ophthalmology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Joanna Wasielica-Poslednik
- Department of Ophthalmology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
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Lee BR, Han KE, Choi KR. The Association between Corneal Biomechanical Properties and Initial Visual Field Defect Pattern in Normal Tension Glaucoma. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2017. [DOI: 10.3341/jkos.2017.58.2.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Bo Ram Lee
- The Institute of Ophthalmology and Optometry, Department of Ophthalmology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, Korea
| | - Kyung Eun Han
- The Institute of Ophthalmology and Optometry, Department of Ophthalmology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, Korea
| | - Kyu Ryong Choi
- The Institute of Ophthalmology and Optometry, Department of Ophthalmology, Mokdong Hospital, Ewha Womans University School of Medicine, Seoul, Korea
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Pérez-Bartolomé F, Martínez de la Casa JM, Camacho Bosca I, Sáenz-Francés F, Aguilar-Munoa S, Martín-Juan A, Garcia-Feijoo J. Correlating Corneal Biomechanics and Ocular Biometric Properties with Lamina Cribrosa Measurements in Healthy Subjects. Semin Ophthalmol 2016; 33:223-230. [DOI: 10.1080/08820538.2016.1208763] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
| | | | - Irene Camacho Bosca
- Hospital Clinico Universitario San Carlos, Ophthalmology, Profesor Martín Lagos S/N, Madrid, Spain
| | - Federico Sáenz-Francés
- Hospital Clinico Universitario San Carlos, Ophthalmology, Profesor Martín Lagos S/N, Madrid, Spain
| | - Soledad Aguilar-Munoa
- Hospital Clinico Universitario San Carlos, Ophthalmology, Profesor Martín Lagos S/N, Madrid, Spain
| | - Alberto Martín-Juan
- Hospital Clinico Universitario San Carlos, Ophthalmology, Profesor Martín Lagos S/N, Madrid, Spain
| | - Julian Garcia-Feijoo
- Hospital Clinico Universitario San Carlos, Ophthalmology, Profesor Martín Lagos S/N, Madrid, Spain
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Matsuura M, Hirasawa K, Murata H, Yanagisawa M, Nakao Y, Nakakura S, Kiuchi Y, Asaoka R. The Relationship between Corvis ST Tonometry and Ocular Response Analyzer Measurements in Eyes with Glaucoma. PLoS One 2016; 11:e0161742. [PMID: 27580243 PMCID: PMC5006993 DOI: 10.1371/journal.pone.0161742] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/10/2016] [Indexed: 11/30/2022] Open
Abstract
It is important to compare the results of Corneal Visualization Scheimpflug Technology instrument (CST) measurements and Reichert Ocular Response Analyzer (ORA) parameters. The purpose of the study was to investigate the association between CST measurements and ORA parameters in ninety-five patients with primary open-angle glaucoma. Measurements of CST, ORA, axial length (AL), average corneal curvature (CC), central corneal thickness (CCT) and intraocular pressure (IOP) with Goldmann applanation tonometry (GAT) were carried out. The association between CST and ORA parameters was assessed using linear regression analysis, with model selection based on the second order bias corrected Akaike Information Criterion index. Measurements from ORA (corneal hysteresis [CH] and corneal response factor [CRF]) had high intraclass correlation coefficients (ICC) and low coefficients of variation, but some CST parameters showed much lower reproducibility, namely: A1 length, A2 length, highest concavity time and peak distance. Of 12 CST parameters tested, 8 were significantly correlated with CH and 10 were significantly correlated with CRF, however, the magnitude of the correlation coefficients were weak to moderate at best. The optimal model to explain CH using CST measurements was given by: CH = -76.3 + 4.6*A1 time + 1.9*A2 time + 3.1 * highest concavity deformation amplitude + 0.016*CCT (R2 = 0.67, p <0.001). Similarly, the optimal model for CRF was given by: CRF = -53.5 + 4.2*A1 time + 1.9*A1 length + 20.8*A1 deformation amplitude + 0.8*A2 time + 0.017*CCT (R2 = 0.73, p <0.001). ORA parameters show higher reproducibility than CST measurements. Although many CST parameters are significantly related to ORA parameters, the strengths of these relationships are weak to moderate.
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Affiliation(s)
- Masato Matsuura
- Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Kazunori Hirasawa
- Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
- Orthoptics and Visual Science, Department of Rehabilitation, School of Allied Health Sciences, Kitasato University, Kanagawa, Japan
| | - Hiroshi Murata
- Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Mieko Yanagisawa
- Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Yoshitaka Nakao
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Shunsuke Nakakura
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Ryo Asaoka
- Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
- * E-mail:
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Pillunat KR, Hermann C, Spoerl E, Pillunat LE. Analyzing biomechanical parameters of the cornea with glaucoma severity in open-angle glaucoma. Graefes Arch Clin Exp Ophthalmol 2016; 254:1345-51. [PMID: 27118038 DOI: 10.1007/s00417-016-3365-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 04/14/2016] [Accepted: 04/19/2016] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The purpose was to investigate a possible association of corneal hysteresis (CH) and corneal resistance factor (CRF) with open-angle glaucoma and the severity of disease. METHODS In this prospective cross-sectional study we recruited 86 open-angle glaucoma patients, 16 patients with ocular hypertension (OHT,) and 44 age-matched controls. Each participant had a complete glaucoma workup including measurements with the Ocular Response Analyzer and computerized perimetry with the Humphrey 30-2 SITA Standard program. Visual field damage was based on mean deviation (MD) and considered as early glaucomatous with a MD > - 6 dB, moderate glaucomatous between -6 and -12 dB and advanced glaucomatous < -12 dB. The association between ORA parameters, glaucoma, and disease severity was evaluated using univariate and multivariate linear regression analyses. RESULTS There was a statistically significant correlation between the biomechanical parameters and intraocular pressure, central corneal thickness, axial length, and age. On average, glaucoma patients had the lowest adjusted CH (8.96 ± 1.43 mmHg) and CRF (9.07 ± 1.93 mmHg) values in comparison to OHT patients (CH: 10.2 ± 1.5 mmHg; CRF: 10.6 ± 2.1 mmHg) and controls (CH: 9.7 ± 1.4 mmHg; CRF: 10.2 ± 1.9 mmHg). This difference was statistically significant (CH: p = 0.003; CRF: p = 0.008). There was also a statistically significant difference in adjusted CH (p = 0.001) and CRF (p = 0.004) values between the controls and the visual field groups, with the lowest values being in the most advanced group. CONCLUSIONS Before interpreting corneal biomechanical parameters, it seems important to adjust the measured data for their underlying influencing factors. Glaucoma patients with lower adjusted CH and CRF probably have more advanced disease and should, therefore, be treated more aggressively and monitored more carefully and frequently.
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Affiliation(s)
- Karin R Pillunat
- Department of Ophthalmology, Medical Faculty Carl Gustav Carus, Technische Universität, Fetscherstrasse 74, 01307, Dresden, Germany.
| | - Cosima Hermann
- Department of Ophthalmology, Medical Faculty Carl Gustav Carus, Technische Universität, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Eberhard Spoerl
- Department of Ophthalmology, Medical Faculty Carl Gustav Carus, Technische Universität, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Lutz E Pillunat
- Department of Ophthalmology, Medical Faculty Carl Gustav Carus, Technische Universität, Fetscherstrasse 74, 01307, Dresden, Germany
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Zheng X, Bao F, Geraghty B, Huang J, Yu A, Wang Q. High intercorneal symmetry in corneal biomechanical metrics. EYE AND VISION 2016; 3:7. [PMID: 26949709 PMCID: PMC4779259 DOI: 10.1186/s40662-016-0037-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 02/20/2016] [Indexed: 12/02/2022]
Abstract
Backgroud To evaluate the symmetry of corneal biomechanical metrics, measured using an ocular response analyzer (ORA) and self-built corneal inflation test platform, in bilateral rabbit corneas and to investigate their relationship with physical intraocular pressure (IOPp). Methods Twenty fresh enucleated eyes from ten rabbits were used for ex vivo whole ocular globe inflation. IOP was increased from 7.5 to 37.5 mmHg with 7.5 mmHg steps and biomechanical metrics were acquired using the ORA. At least 3 examinations were performed at each pressure stage. Two biomechanical metrics, corneal hysteresis (CH) and corneal resistance factor (CRF) were recorded and analyzed as a function of IOPp. Corneal specimens were then excised from the intact ocular globe and tested under inflation conditions up to 45.7 mmHg posterior pressure. The experimental pressure-deformation data was analyzed using an inverse modeling procedure to derive the stress-strain behavior of the cornea. Results A comparison of corneal shape parameters showed no statistically significant difference (P > 0.05) between bilateral eyes. Similarly, there were no statistically significant differences in values of CH, CRF and corneal stiffness (as measured by the tangent modulus, Et) between bilateral eyes (CH: F = 0.94, P = 0.54; CRF: F = 4.42, P = 0.35; Et: F = 3.15, P = 0.12) at different pressure levels. IOPp was highly correlated with CRF while the relationship with CH was less pronounced. Conclusions An obvious interocular symmetry in biomechanical metrics is found in this research. IOP has been shown to have important influences on the value of CRF provided by ORA.
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Affiliation(s)
- XiaoBo Zheng
- The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province 325027 China ; The Institution of Ocular Biomechanics, Eye Hospital, Wenzhou Medical University, No. 270# Xueyuan West Road, Wenzhou City, Zhejiang Province 325027 China
| | - FangJun Bao
- The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province 325027 China ; The Institution of Ocular Biomechanics, Eye Hospital, Wenzhou Medical University, No. 270# Xueyuan West Road, Wenzhou City, Zhejiang Province 325027 China
| | - Brendan Geraghty
- School of Engineering, University of Liverpool, Liverpool, L69 3GH UK
| | - JinHai Huang
- The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province 325027 China ; The Institution of Ocular Biomechanics, Eye Hospital, Wenzhou Medical University, No. 270# Xueyuan West Road, Wenzhou City, Zhejiang Province 325027 China
| | - Ayong Yu
- The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province 325027 China ; The Institution of Ocular Biomechanics, Eye Hospital, Wenzhou Medical University, No. 270# Xueyuan West Road, Wenzhou City, Zhejiang Province 325027 China
| | - QinMei Wang
- The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province 325027 China ; The Institution of Ocular Biomechanics, Eye Hospital, Wenzhou Medical University, No. 270# Xueyuan West Road, Wenzhou City, Zhejiang Province 325027 China
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Nuyen B, Mansouri K. Detecting IOP Fluctuations in Glaucoma Patients. Open Ophthalmol J 2016; 10:44-55. [PMID: 27014387 PMCID: PMC4780505 DOI: 10.2174/1874364101610010044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 08/18/2015] [Accepted: 08/18/2015] [Indexed: 11/12/2022] Open
Abstract
Lowering intraocular pressure (IOP) remains the guiding principle of glaucoma management. Although IOP is the only treatable risk factor, its 24-hour behavior is poorly understood. Current glaucoma management usually relies on single IOP measurements during clinic hours, even though IOP is a dynamic parameter with rhythms dependent on individual patients. It has further been shown that most glaucoma patients have their highest IOP measurements outside clinic hours. The fact that these IOP peaks go largely undetected may explain why certain patients progress in their disease despite treatment. Nevertheless, single IOP measurements have determined all major clinical guidelines regarding glaucoma treatment. Other potentially informative parameters, such as fluctuations in IOP and peak IOP, have been neglected, and effects of IOP-lowering interventions on such measures are largely unknown. Continuous 24-hour IOP monitoring has been an interest for more than 50 years, but only recent technological advances have provided clinicians with a device for such an endeavor. This review discusses current uses and shortcomings of current measurement techniques, and provides an overview on current and future methods for 24-hour IOP assessment. It may be possible to incorporate continuous IOP monitoring into clinical practice, potentially to reduce glaucoma-related vision loss.
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Affiliation(s)
- Brenda Nuyen
- Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California, USA
| | - Kaweh Mansouri
- Glaucoma Center, Montchoisi Clinic, Genolier Swiss Vision Network, Lausanne, Switzerland
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, Colorado, USA
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Park JY, Lee JW, Shin JH. The Short-Term Effect of Prostaglandin Analog Monotherapy on Corneal Biomechanical Properties in Normal Tension Glaucoma Patients. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2016. [DOI: 10.3341/jkos.2016.57.3.477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jung Yul Park
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Ji Woong Lee
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Jong Hoon Shin
- Department of Ophthalmology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
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Hussnain SA, Alsberge JB, Ehrlich JR, Shimmyo M, Radcliffe NM. Change in corneal hysteresis over time in normal, glaucomatous and diabetic eyes. Acta Ophthalmol 2015; 93:e627-30. [PMID: 25923367 DOI: 10.1111/aos.12726] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/23/2015] [Indexed: 11/29/2022]
Abstract
PURPOSE Corneal hysteresis (CH) is lower in glaucomatous eyes. The aim of this study was to determine and compare the change in CH over time between normal, open angle glaucoma (POAG) and diabetic subjects. METHODS We retrospectively analysed records of patients undergoing assessment with the Ocular Response Analyzer (Reichert, Corp., New York, NY, USA). Right eyes with at least 7 measurements were included. Patients with ocular pathology other than POAG were excluded. Two-sample t-tests, chi-squared and logistic regression were used to analyse data. RESULTS A total of 1418 normal and 322 POAG patients were included. Patients with POAG were significantly older (70.73 ± 11.33 vs. 61.59 ± 16.56 years; p < 0.001), had a longer follow-up (4.14 ± 1.34 vs. 2.72 ± 1.49 years; p < 0.001) and had lower CH (9.58 ± 2.17 vs. 9.95 ± 2.19 mmHg p = 0.01), but there were no gender differences between groups (61.5 vs. 57.7% female; p = 0.21). We observed a significantly greater decrease in CH among patients with POAG (-0.11 ± 0.73 vs. 0.07 ± 2.31 mm Hg/year; p = 0.02). The relation between ∆CH/year and diagnosis persisted after adjusting for age and follow-up time (OR 0.90; 95% CI 0.82, 0.99; p = 0.03). We found CH to be higher in diabetics vs. non-diabetics (10.34 ± 2.04 vs. 9.88 ± 2.19; p = 0.02), but ∆CH/year was not different (0.07 ± 1.27 vs. 0.03 ± 2.10; p = 0.77). CONCLUSIONS Patients with POAG in this study had a significantly greater rate of CH decline compared to normal. There was no significant difference in rate of CH change in diabetic and non-diabetic patients.
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Affiliation(s)
- Syed Amal Hussnain
- Department of Ophthalmology; Weill Cornell Medical College; New York NY USA
| | - Joseph B. Alsberge
- Department of Ophthalmology; Weill Cornell Medical College; New York NY USA
| | - Joshua R. Ehrlich
- Department of Ophthalmology; Weill Cornell Medical College; New York NY USA
| | - Mitsugu Shimmyo
- Department of Ophthalmology; New York Medical College; Valhalla NY USA
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Blumberg D, Skaat A, Liebmann JM. Emerging risk factors for glaucoma onset and progression. PROGRESS IN BRAIN RESEARCH 2015; 221:81-101. [PMID: 26518074 DOI: 10.1016/bs.pbr.2015.04.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Glaucoma is a complex, multifactorial neurodegenerative disease process that leads to progressive damage to the optic nerve and irreversible visual impairment. Identification of ocular and systemic risk factors for disease onset and progression is critical for disease detection and surveillance. Although a great deal is known about risk factors for glaucoma, our expanding knowledge of glaucoma genotypes and phenotypes combined with advancements in technology and understanding of disease progression is rapidly enhancing our understanding of who is at greatest risk for glaucomatous visual impairment.
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Affiliation(s)
- Dana Blumberg
- Bernard and Shirlee Brown Glaucoma Research Laboratory, Edward S. Harkness Eye Institute, Columbia University Medical Center, New York, NY, USA
| | - Alon Skaat
- Goldschleger Eye Institute, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jeffrey M Liebmann
- Bernard and Shirlee Brown Glaucoma Research Laboratory, Edward S. Harkness Eye Institute, Columbia University Medical Center, New York, NY, USA.
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Bao F, Deng M, Wang Q, Huang J, Yang J, Whitford C, Geraghty B, Yu A, Elsheikh A. Evaluation of the relationship of corneal biomechanical metrics with physical intraocular pressure and central corneal thickness in ex vivo rabbit eye globes. Exp Eye Res 2015; 137:11-7. [PMID: 26026878 DOI: 10.1016/j.exer.2015.05.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/14/2015] [Accepted: 05/26/2015] [Indexed: 10/23/2022]
Abstract
The relationship of corneal biomechanical metrics provided by the Ocular Response Analyzer (ORA) and Corvis ST (CVS) with physical intraocular pressure (IOPp) and central corneal thickness (CCT) was evaluated. Thirty fresh enucleated eyes of 30 rabbits were used in ex vivo whole globe inflation experiments. IOPp was measured with a pressure transducer and increased from 7.5 to 37.5 mmHg in steps of 7.5 mmHg while biomechanical data was acquired using the ORA and CVS. At least 3 examinations were performed at each pressure level, where CCT and twelve biomechanical metrics were recorded and analyzed as a function of IOPp. The biomechanical metrics included corneal hysteresis (CH) and corneal resistance factor (CRF), obtained by the ORA. They also included the applanation times (A1T, A2T), lengths (A1L, A2L) and velocities (A1V, A2V), in addition to the highest concavity time (HCT), peak distance (PD), radius (HR) and deformation amplitude (DA), obtained by the CVS. The variation of CCT and the twelve biomechanical metrics for the 30 rabbit eyes tested across the 5 pressure stages considered (inter-pressure differences) were statistically significant (P = 0.00). IOPp was highly to moderately correlated with most biomechanical metrics, especially CRF, A1T, A1V, A2V, PD and DA, while the relationships with CH, A2T, A1L and HCT were poor. IOP has important influences on most corneal biomechanical metrics provided by CVS and ORA. Two biomechanical metrics A1V and HR were influenced by CCT after correcting for the effect of IOP in most pressure stages, while the correlation with others were weak. Comparisons of research groups based on ORA and CVS with different IOPs and CCTs may lead to possible misinterpretations if both or one of which are not considered in the analysis.
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Affiliation(s)
- FangJun Bao
- The Affiliated Eye Hospital of WenZhou Medical University, Wenzhou, 325027, China; The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, Zhejiang Province, 325027, China
| | - ManLi Deng
- The Affiliated Eye Hospital of WenZhou Medical University, Wenzhou, 325027, China; The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, Zhejiang Province, 325027, China
| | - QinMei Wang
- The Affiliated Eye Hospital of WenZhou Medical University, Wenzhou, 325027, China; The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, Zhejiang Province, 325027, China
| | - JinHai Huang
- The Affiliated Eye Hospital of WenZhou Medical University, Wenzhou, 325027, China; The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, Zhejiang Province, 325027, China
| | - Jing Yang
- The Affiliated Eye Hospital of WenZhou Medical University, Wenzhou, 325027, China; The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, Zhejiang Province, 325027, China
| | - Charles Whitford
- School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - Brendan Geraghty
- School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - Ayong Yu
- The Affiliated Eye Hospital of WenZhou Medical University, Wenzhou, 325027, China; The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, Zhejiang Province, 325027, China.
| | - Ahmed Elsheikh
- School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK; National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, UK
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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.
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Eldaly MA. Goldmann versus Disposable Applanation Tonometer Tips in Glaucoma Patients and Normal Subjects. Curr Eye Res 2015; 41:521-5. [PMID: 25834939 DOI: 10.3109/02713683.2015.1015144] [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: 11/13/2022]
Abstract
PURPOSE To assess agreement of intraocular pressure (IOP) measured with Goldmann applanation and disposable Luneau SA applanation prisms in glaucoma patients compared with normal subjects. METHODS In a prospective comparative study, one eye per primary open-angle glaucoma (POAG) patient was measured for IOP using Goldmann and disposable Luneau SA (Tonojet) applanation tonometry prisms. Glaucoma patients found with IOP < 21 mmHg were compared to an age-matched group of normal subjects. The main outcomes measured were IOP and the difference in IOP between either prism. Bland-Altman plots were used to study the agreement between measurements. Regression analysis was applied to either group. RESULTS One hundred and four POAG patients (eyes) were enrolled into this study. Seventy-one of them were found with IOPs < 21 mmHg, and were compared to 71 normal subjects (eyes). The mean difference between either prism was almost similar, 2.0 ± 2.0 and 2.1 ± 1.7 mmHg in the glaucoma and normal eye groups, respectively. Bias of two SD from the mean ranged from -1.8 to 5.8 mmHg in glaucoma group and -1.2 to 5.4 mmHg with normal subjects (p < 0.0001 in either group). The inaccuracy was non-systematic with glaucoma patients while was systematic with normal subjects. CONCLUSIONS The disagreement between disposables and standard Goldmann tips followed different patterns in glaucoma patients when compared with normal subjects. The use of the Goldmann tip is advised with glaucoma patients.
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Affiliation(s)
- Mohamed A Eldaly
- a Ophthalmology Department, Faculty of Medicine , Cairo University , Cairo , Egypt
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Abstract
According to the World Health Organization, glaucoma is the leading cause of irreversible blindness worldwide. Although intraocular pressure (IOP) is not considered any more to be a defining feature of the disease, its lowering remains the only treatment option for glaucoma. Therefore, accurate and precise measurement of IOP is the cornerstone of glaucoma. Intraocular pressure is a highly dynamic physiological parameter with individual circadian rhythms. The main limitation of current tonometry methods remains the static and mostly office-based nature of their measurements. This review provides a brief historical overview on tonometry and discusses current tonometry instruments. In recent years, approaches to 24-hour IOP monitoring have been introduced, and there is hope that they may become part of routine clinical management in the future.
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Affiliation(s)
- Brenda Nuyen
- From the *Hamilton Glaucoma Center and the Department of Ophthalmology, University of California, San Diego, La Jolla, CA; †Glaucoma Sector, Department of Ophthalmology, Geneva University Hospitals, Geneva, Switzerland; and ‡Department of Ophthalmology, University of Colorado School of Medicine, Denver, CO
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Han JW, Ha SJ. Comparison of Corvis ST Tonometer to Other Tonometers and Clinical Usefulness of Corvis ST Tonometer. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2015. [DOI: 10.3341/jkos.2015.56.3.404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jung Woo Han
- Department of Ophthalmology, Soonchunhyang University Hospital, Soonchunhyang University College of Medicine, Seoul, Korea
| | - Seung Joo Ha
- Department of Ophthalmology, Soonchunhyang University Hospital, Soonchunhyang University College of Medicine, Seoul, Korea
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