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Yang Z, Miao N, Wang L, Ma K. Comparison of different correction formulas and measurement methods for the accurate determination of intraocular pressure after SMILE and FS-LASIK surgery. BMC Ophthalmol 2022; 22:404. [PMID: 36217120 PMCID: PMC9549448 DOI: 10.1186/s12886-022-02620-7] [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: 07/13/2022] [Accepted: 09/26/2022] [Indexed: 11/23/2022] Open
Abstract
Background To compare the accuracy of non-contact tonometry, Pentacam, and corneal visualization Scheimpflug technology (Corvis ST) for the measurement of intraocular pressure (IOP) after small incision lenticule extraction (SMILE) or femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery. Methods A total of 49 patients (98 eyes) undergoing FS-LASIK or SMILE surgery at West China Hospital, Sichuan University from January to March 2021 were enrolled in this prospective, comparative, self-controlled study. IOP values were measured with non-contact tonometer, Pentacam, and Corvis ST before surgery and 1 month after surgery. Pentacam-derived postoperative IOP values were corrected using five correction formulas (Ehlers, Shah, Dresden, Orssengo-Pye, and Kohlhaas), while Corvis ST-derived values were corrected using a single formula. Results In the SMILE group, no significant differences were observed between the IOP values corrected with the Shah formula before and after surgery (t = 0.17, P = 0.869), whereas postoperative IOP values corrected with the other formulas were significantly different from the corresponding preoperative measurements (P < 0.05). In the FS-LASIK group, postoperative IOP values corrected with the Ehlers, Shah, or Corvis ST formulas were significantly different from the corresponding preoperative IOP measurements (P < 0.05), but no significant differences were observed between pre- and postoperative IOP values corrected with the Dresden (t = − 0.08, P = 0.941), Orssengo-Pye (t = − 0.52, P = 0.604), or Kohlhaas (t = 1.22, P = 0.231) formulas. Conclusions Pentacam’s Shah correction formula seemed to be the most appropriate method for accurately measuring postoperative IOP in patients undergoing SMILE surgery, while the Dresden, Orssengo-Pye, and Kohlhaas correction formulas of Pentacam were identified as the most reliable methods for estimating IOP in patients after FS-LASIK surgery. Supplementary Information The online version contains supplementary material available at 10.1186/s12886-022-02620-7.
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Affiliation(s)
- Zhiqing Yang
- Department of Ophthalmology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan Province, China.,West China Medical School, Sichuan University, Chengdu, 610041, Sichuan Province, China
| | - Na Miao
- Department of Ophthalmology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan Province, China
| | - Lixiang Wang
- Department of Ophthalmology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan Province, China
| | - Ke Ma
- Department of Ophthalmology, West China Hospital of Sichuan University, No. 37 Guoxue Alley, Chengdu, 610041, Sichuan Province, China.
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2
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Iglesias M, Kudsieh B, Laiseca A, Santos C, Nadal J, Barraquer R, Casaroli-Marano RP. Intraocular pressure after myopic laser refractive surgery measured with a new Goldmann convex prism: correlations with GAT and ORA. BMC Ophthalmol 2022; 22:79. [PMID: 35168601 PMCID: PMC8849021 DOI: 10.1186/s12886-022-02309-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/09/2022] [Indexed: 12/04/2022] Open
Abstract
Background The purpose of this study is to describe measurements using a newly developed modified Goldmann convex tonometer (CT) 1 year after myopic laser refractive surgery. Intraocular pressure (IOP) measurements were compared with IOP values obtained by Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA). Methods Prospective double-masked study performed on thirty eyes of thirty patients that underwent laser in situ keratomileusis (LASIK; n = 19) or photorefractive keratectomy (PRK; n = 11). IOP was measured before and 3 and 12 months after surgery. Intraclass correlation coefficient (ICC) and Bland-Altman plot were calculated to assess the agreement between GAT, CT, IOPg (Goldmann-correlated IOP) and IOPcc (corneal-compensated IOP) from ORA. Results Twelve months after LASIK, IOP measured with CT showed the best correlation with IOP measured with GAT before surgery (GATpre) (ICC = 0.886, 95% CI: 0.703–0.956) (15.60 ± 3.27 vs 15.80 ± 3.22; p < 0.000). However, a moderate correlation was found for IOP measured with IOPcc and CT 12 months after LASIK (ICC = 0.568, 95% CI: − 0.185 – 0.843) (15.80 ± 3.22 vs 12.87 ± 2.77; p < 0.004). Twelve months after PRK, CT showed a weak correlation (ICC = − 0.266, 95% CI: − 3.896 – 0.663), compared to GATpre (17.30 ± 3.47 vs 16.01 ± 1.45; p < 0.642), as well as poor correlation (ICC = 0.256, 95% CI: − 0.332 – 0.719) with IOPcc (17.30 ± 3.47 vs 13.38 ± 1.65; p < 0.182). Conclusions Twelve months after LASIK, IOP measured with CT strongly correlated with GAT before surgery and could therefore provide an alternative method for measuring IOP after this surgery. More studies regarding this new convex prism are needed to assess its accuracy.
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Affiliation(s)
- María Iglesias
- Instituto Universitario Barraquer, Barraquer Ophthalmology Centre, Laforja 88, 08012, Barcelona, Spain.
| | - Bachar Kudsieh
- Department of Ophthalmology, Hospital Universitario Puerta De Hierro, 28222, Madrid, Spain
| | - Andrea Laiseca
- Instituto Universitario Barraquer, Barraquer Ophthalmology Centre, Laforja 88, 08012, Barcelona, Spain
| | - Cristina Santos
- Unitat Antropologia Biològica, Department Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autònoma de Barcelona (UAB), 08193, Barcelona, Spain
| | - Jeroni Nadal
- Instituto Universitario Barraquer, Barraquer Ophthalmology Centre, Laforja 88, 08012, Barcelona, Spain
| | - Rafael Barraquer
- Instituto Universitario Barraquer, Barraquer Ophthalmology Centre, Laforja 88, 08012, Barcelona, Spain.,International University of Catalunya (UIC), 08017, Barcelona, Spain
| | - Ricardo P Casaroli-Marano
- Department of Surgery, School of Medicine and Hospital Clinic de Barcelona, University of Barcelona (UB), 08036, Barcelona, Spain
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3
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Gedde SJ, Vinod K, Wright MM, Muir KW, Lind JT, Chen PP, Li T, Mansberger SL. Primary Open-Angle Glaucoma Preferred Practice Pattern®. Ophthalmology 2021; 128:P71-P150. [DOI: 10.1016/j.ophtha.2020.10.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 12/17/2022] Open
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Gedde SJ, Lind JT, Wright MM, Chen PP, Muir KW, Vinod K, Li T, Mansberger SL. Primary Open-Angle Glaucoma Suspect Preferred Practice Pattern®. Ophthalmology 2021; 128:P151-P192. [DOI: 10.1016/j.ophtha.2020.10.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 11/28/2022] Open
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5
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Song JS, Lee YB, Kim JA, Lee EJ, Kim H. Association between corneal refractive surgery and the prevalence of glaucoma: Korea National Health and Nutrition Examination Survey 2010-2012. Br J Ophthalmol 2020; 106:172-176. [PMID: 33097521 DOI: 10.1136/bjophthalmol-2020-317133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/24/2020] [Accepted: 10/03/2020] [Indexed: 11/04/2022]
Abstract
AIM To determine the relationship between corneal refractive surgery and the prevalence of glaucoma in the Korean population. METHODS Data were obtained from the Korea National Health and Nutrition Examination Survey (KNHANES), a population-based cross-sectional study using a complex, stratified, multistage, probability-cluster survey. This study included 604 eyes that had undergone myopic corneal refractive surgery, and 3389 control eyes without a history of any ocular surgery and having a spherical equivalent (SE) <-3.00 D, obtained from the KNHANES database for the years 2010-2012. Glaucoma diagnosis was based on the International Society of Geographical and Epidemiological Ophthalmology criteria. The association between a history of corneal refractive surgery and the prevalence of glaucoma was analysed using logistic regression analysis, after adjusting for potential confounding factors. RESULTS Glaucoma prevalence did not differ between eyes that had and had not undergone corneal refractive surgery (p=0.675). After adjusting for age, sex, SE, and intraocular pressure, multivariate logistic regression analysis found that corneal refractive surgery was significantly associated with an increased risk of glaucoma (OR 9.14, p=0.002; 95% CI 2.22 to 37.69). Subgroup analysis that only included control eyes with a refraction cut-off <-3.70 D found that corneal refractive surgery was not significantly associated with glaucoma. CONCLUSIONS History of corneal refractive surgery was associated with a higher prevalence of glaucoma in the Korean population. However, this association was not observed in eyes with a higher degree of myopia.
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Affiliation(s)
- Jae Shin Song
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Young Bok Lee
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Ji-Ah Kim
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Eun Ji Lee
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Korea
| | - Hyunjoong Kim
- Department of Statistics and Data Science, Yonsei University, Seoul, Korea
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6
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Nuzzi R, Marolo P, Nuzzi A. The Hub-and-Spoke Management of Glaucoma. Front Neurosci 2020; 14:180. [PMID: 32256306 PMCID: PMC7090234 DOI: 10.3389/fnins.2020.00180] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 02/18/2020] [Indexed: 12/19/2022] Open
Abstract
Glaucoma is an extremely significant public health issue, since it is the most common cause of irreversible blindness worldwide, nevertheless it is still widely undiagnosed because of its devious nature. Glaucoma diagnosis criteria are well-defined and have to be strictly observed and recognized: the earlier the disease is diagnosed, the earlier the patient can undergo the most suitable treatment, the better can be the prognosis. The three levels of prevention are essential in the approach to the disease and its pathophysiological features make it eligible for screening. This review provides an overview of the current state of the art in glaucoma management, starting from its prevention and coming to the hub-and-spoke organization. This model applied to glaucoma aims to direct patients toward professional and not professional figures who may guide them in integrated care pathway. This path should be designed in accordance with best practice to coordinate glaucoma prevention, diagnosis, treatment and follow up with the best cost-benefit ratio, protecting both the interests of the patient and of the society.
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Affiliation(s)
- Raffaele Nuzzi
- Eye Clinic Section, Department of Surgical Sciences, University of Turin, Turin, Italy
| | - Paola Marolo
- Eye Clinic Section, Department of Surgical Sciences, University of Turin, Turin, Italy
| | - Alessia Nuzzi
- Department of Clinical Sciences and Community Health, Eye Clinic San Giuseppe Hospital, IRCCS Multimedica, University of Milan, Milan, Italy
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7
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Zhang H, Sun Z, Li L, Sun R, Zhang H. Comparison of intraocular pressure measured by ocular response analyzer and Goldmann applanation tonometer after corneal refractive surgery: a systematic review and meta-analysis. BMC Ophthalmol 2020; 20:23. [PMID: 31924174 PMCID: PMC6954592 DOI: 10.1186/s12886-019-1288-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 12/27/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Accurate measurement of intraocular pressure (IOP) after corneal refractive surgery is of great significance to clinic, and comparisons among various IOP measuring instruments are not rare, but there is a lack of unified analysis. Although Goldmann Applanation Tonometer (GAT) is currently the internationally recognized gold standard for IOP measurement, its results are severely affected by central corneal thickness (CCT). Ocular Response Analyzer (ORA) takes certain biomechanical properties of cornea into account and is supposed to be less dependent of CCT. In this study, we conducted the meta-analysis to systematically assess the differences and similarities of IOP values measured by ORA and GAT in patients after corneal refractive surgery from the perspective of evidence-based medicine. METHODS The authors searched electronic databases (MEDLINE, EMBASE, Web of science, Cochrane library and Chinese electronic databases of CNKI and Wanfang) from Jan. 2005 to Jan. 2019, studies describing IOP comparisons measured by GAT and ORA after corneal refractive surgery were included. Quality assessment, subgroup analysis, meta-regression analysis and publication bias analysis were applied in succession. RESULTS Among the 273 literatures initially retrieved, 8 literatures (13 groups of data) with a total of 724 eyes were included in the meta-analysis, and all of which were English literatures. In the pooled analysis, the weighted mean difference (WMD) between IOPcc and IOPGAT was 2.67 mmHg (95% CI: 2.20~3.14 mmHg, p < 0.0001), the WMD between IOPg and IOPGAT was - 0.27 mmHg (95% CI: - 0.70~0.16 mmHg, p = 0.2174). In the subgroup analysis of postoperative IOPcc and IOPGAT, the heterogeneity among the data on surgical procedure was zero, while the heterogeneity of other subgroups was still more than 50%. The comparison of the mean difference of pre- and post-operative IOP (∆IOP) was: mean-∆IOPg > mean-∆IOPGAT > mean-∆IOPcc. CONCLUSIONS IOPcc, which is less dependent on CCT, may be more close to the true IOP after corneal refractive surgery compared with IOPg and IOPGAT, and the recovery of IOPcc after corneal surface refractive surgery may be more stable than that after lamellar refractive surgery.
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Affiliation(s)
- Hui Zhang
- School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China
| | - Zhengtao Sun
- School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China
| | - Lin Li
- School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China.,Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China
| | - Ran Sun
- Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Haixia Zhang
- School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China. .,Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China. .,School of Engineering, University of Liverpool, Liverpool, UK.
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8
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Bao F, Huang W, Zhu R, Lu N, Wang Y, Li H, Wu S, Lin H, Wang J, Zheng X, Huang J, Li Y, Wang Q, Elsheikh A. Effectiveness of the Goldmann Applanation Tonometer, the Dynamic Contour Tonometer, the Ocular Response Analyzer and the Corvis ST in Measuring Intraocular Pressure following FS-LASIK. Curr Eye Res 2019; 45:144-152. [PMID: 31869261 DOI: 10.1080/02713683.2019.1660794] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Purpose: To test the performance of the four tonometers in providing IOP measurements that were free of the effects of corneal biomechanics changes caused by refractive surgery.Methods: Four tonometers were employed to provide IOP measurements for 65 participants who accepted Femtosecond laser-assisted LASIK (FS-LASIK). The measurements included GAT-IOP by the Goldmann Applanation Tonometer, DCT-IOP by the Dynamic Contour Tonometer, Goldmann-correlated IOP (ORA-IOPg) and corneal-compensated IOP (ORA-IOPcc) by the Ocular Response Analyzer, and uncorrected IOP (CVS-IOP) and biomechanically corrected IOP (CVS-bIOP) by the Corvis ST. Statistical analyses were performed to assess the association of the differences in IOP caused by FS-LASIK with central corneal thickness (CCT), mean corneal curvature (Km), age, refractive error correction (REC), optical zone diameter (OZD), ablation zone diameter (AZD), residual stromal bed thickness (RSB) and RSB ratio (RSB/CCT). Multiple linear regression models were constructed to explore factors influencing IOP changes.Results: All four tonometers exhibited significant differences between IOP measurements taken pre and post-surgery except for CVS-bIOP in the low to moderate myopia group (t = 1.602, p = .12). CVS-bIOP, followed by DCT-IOP, provided the best agreement between pre and post-FS-LASIK measurements with the lowest differences in IOP and the narrowest limits of agreement. The pre-post IOP differences were also significantly associated with the reduction in CCT in only GAT-IOP, ORA-IOPg, and CVS-IOP. CVS-bIOP and ORA-IOPcc were the only measurements that were not correlated with CCT, Km or age both before and after FS-LASIK.Conclusions: The biomechanically corrected bIOP from the Corvis ST provided post-FS-LASIK measurements that were in closest agreement with those obtained before surgery. In comparison, GAT-IOP, ORA-IOPg, ORA-IOPcc, and CVS-IOP appeared to be more influenced by the changes in corneal biomechanics caused by FS-LASIK.
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Affiliation(s)
- Fangjun Bao
- Eye Hospital, WenZhou Medical University, Wenzhou, China.,The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, China
| | - Wei Huang
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Rong Zhu
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Nanji Lu
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Yuan Wang
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Hechen Li
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Songan Wu
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Huini Lin
- 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
| | - Xiaobo Zheng
- Eye Hospital, WenZhou Medical University, Wenzhou, China.,The Institution of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, China
| | - JinHai Huang
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Yiyu Li
- Eye Hospital, WenZhou Medical University, Wenzhou, China
| | - Qinmei Wang
- 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.,School of Biological Science and Biomedical Engineering, Beihang University, Beijing, China
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9
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Jin Z, Khazaeinezhad R, Zhu J, Yu J, Qu Y, He Y, Li Y, Gomez Alvarez-Arenas TE, Lu F, Chen Z. In-vivo 3D corneal elasticity using air-coupled ultrasound optical coherence elastography. BIOMEDICAL OPTICS EXPRESS 2019; 10:6272-6285. [PMID: 31853399 PMCID: PMC6913398 DOI: 10.1364/boe.10.006272] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/03/2019] [Accepted: 10/10/2019] [Indexed: 05/03/2023]
Abstract
Corneal elasticity can resist elastic deformations under intraocular pressure to maintain normal corneal shape, which has a great influence on corneal refractive function. Elastography can measure tissue elasticity and provide a powerful tool for clinical diagnosis. Air-coupled ultrasound optical coherence elastography (OCE) has been used in the quantification of ex-vivo corneal elasticity. However, in-vivo imaging of the cornea remains a challenge. The 3D air-coupled ultrasound OCE with an axial motion artifacts correction algorithm was developed to distinguish the in-vivo cornea vibration from the axial eye motion in anesthetized rabbits and visualize the elastic wave propagation clearly. The elastic wave group velocity of in-vivo rabbit cornea was measured to be 5.96 ± 0.55 m/s, which agrees with other studies. The results show the potential of 3D air-coupled ultrasound OCE with an axial motion artifacts correction algorithm for quantitative in-vivo assessment of corneal elasticity.
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Affiliation(s)
- Zi Jin
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou 325003, Zhejiang, China
- These authors contributed equally to this work
| | - Reza Khazaeinezhad
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
- These authors contributed equally to this work
| | - Jiang Zhu
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
| | - Junxiao Yu
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
| | - Yueqiao Qu
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
| | - Youmin He
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
| | - Yan Li
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
| | - Tomas E Gomez Alvarez-Arenas
- Institute of Physical and Information Technologies, Spanish National Research Council (CSIC), 28006 Madrid, Spain
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou 325003, Zhejiang, China
| | - Zhongping Chen
- Beckman Laser Institute, Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92612, USA
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Abstract
PURPOSE To study peculiarities of intraocular pressure (IOP) measurement by different methods in patients with changes in corneal biomechanical properties. MATERIAL AND METHODS The study enrolled 154 patients (290 eyes) divided into 3 groups according to the condition of their corneas in terms of biomechanical properties. Group I consisted of 84 patients (168 eyes) with conditionally 'normal' cornea and corneal thickness ranging from 470 to 660 μm. Group II included 44 patients (70 eyes) with keratokonus. Group III consisted of 26 patients (52 eyes) after LASIK. IOP pressure was measured in each patient by pneumotonometry, Maklakov tonometry, and dynamic bidirectional pneumo-applanation of the cornea. Biomechanical properties were evaluated with dynamic pneumo-impression method. RESULTS The study revealed that in patients of groups I and III, corneal biomechanics affected indices of corneal compensated IOP and Maklakov's IOP to a lesser extent, as opposed to measurements of Goldman tonometry and pneumotonometry. In group II, Maklakov's tonometry had less IOP measurement inaccuracies in comparison to other evaluated methods due to larger applanation surface. CONCLUSION Changes in biomechanical properties of the cornea can complicate interpretation of the results of different methods of IOP measurement. Accurate determination of IOP requires consideration of biomechanical properties of the cornea, as well as anamnesis data on past corneal diseases or keratorefractive surgeries.
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Affiliation(s)
- I A Bubnova
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
| | - S V Asatryan
- Research Institute of Eye Diseases, 11A Rossolimo St., Moscow, Russian Federation, 119021
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11
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Matsuura M, Murata H, Fujino Y, Yanagisawa M, Nakao Y, Tokumo K, Nakakura S, Kiuchi Y, Asaoka R. Relationship between novel intraocular pressure measurement from Corvis ST and central corneal thickness and corneal hysteresis. Br J Ophthalmol 2019; 104:563-568. [DOI: 10.1136/bjophthalmol-2019-314370] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/30/2019] [Accepted: 06/17/2019] [Indexed: 11/03/2022]
Abstract
AimsCorvis ST (CST) yields biomechanical corrected IOP (bIOP) which is purported to be less dependent on biomechanical properties. In our accompanied paper, it was suggested that the repeatability of bIOP is high. The purpose of the current study was to assess the relationship between intraocular pressure (IOP) measured with CST and central corneal thickness (CCT) and corneal hysteresis (CH), in comparison with IOP measured with Goldmann applanation tonometry (GAT) and the ocular response analyzer (ORA).MethodsA total of 141 eyes from 141 subjects (35 healthy eyes and 106 glaucomatous eyes) underwent IOP measurements with GAT, CST and ORA. The relationships between IOP measurements (ORA-IOPg, ORA-IOPcc, CST-bIOP and GAT IOP) and biomechanical properties (CCT, CH and corneal resistance factor (CRF)) were analysed using the linear regression analysis.ResultsIOPg, IOPcc and GAT IOP were significantly associated with CCT (p<0.001), whereas bIOP was not significantly associated with CCT (p=0.19). IOPg, bIOP and GAT IOP were significantly associated with CH (IOPg: p<0.001; bIOP: p<0.001; GAT IOP: p=0.0054), whereas IOPcc was not significantly associated with CH (p=0.18). All of IOP records were associated with CRF (p<0.001).ConclusionThe bIOP measurement from CST is independent from CCT, but dependent on CH and CRF.
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12
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Corneal hysteresis in post-radial keratotomy primary open-angle glaucoma. Graefes Arch Clin Exp Ophthalmol 2018; 256:1971-1976. [DOI: 10.1007/s00417-018-4073-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/24/2018] [Accepted: 07/16/2018] [Indexed: 11/27/2022] Open
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13
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Chen KJ, Joda A, Vinciguerra R, Eliasy A, Sefat SMM, Kook D, Geraghty B, Roberts CJ, Elsheikh A. Clinical evaluation of a new correction algorithm for dynamic Scheimpflug analyzer tonometry before and after laser in situ keratomileusis and small-incision lenticule extraction. J Cataract Refract Surg 2018; 44:581-588. [PMID: 29685776 DOI: 10.1016/j.jcrs.2018.01.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 01/04/2018] [Accepted: 01/05/2018] [Indexed: 10/17/2022]
Abstract
PURPOSE To compare a biomechanically corrected intraocular pressure (bIOP) algorithm provided by the dynamic Scheimpflug analyzer (Corvis ST) with Goldmann applanation tonometry IOP (Goldmann IOP) and standard dynamic Scheimpflug analyzer IOP measurements before and after laser in situ keratomileusis (LASIK) and refractive lenticule extraction small-incision lenticule extraction (SMILE) surgeries. SETTING Smile Eye Clinic, Munich, Germany, and University of Liverpool, Liverpool, United Kingdom. DESIGN Retrospective case series. METHODS Patients scheduled for LASIK and patients scheduled for small-incision lenticule extraction for myopia or myopic astigmatism were included. The preoperative and postoperative evaluations included Goldmann, Scheimpflug tomography, and dynamic Scheimpflug analyzer IOP measurements. RESULTS The study comprised 14 patients in the LASIK group and 22 patients in the small-incision lenticule extraction group. Preoperative Goldmann IOP and Scheimpflug analyzer IOP values showed significant positive correlation with central corneal thickness (CCT) (P = .05 for LASIK; P = .003 for small-incision lenticule extraction). No significant correlation was found between bIOP and CCT (P > .05). After both surgeries, there were significant decreases in Goldmann IOP (-3.2 mm Hg ± 3.4 [SD] and -3.2 ± 2.1 mm Hg, respectively; both P < .001) and Scheimpflug analyzer IOP (-3.7 ± 2.1 mm Hg and -3.3 ± 2.0 mm Hg, respectively, both P < .001) compared with preoperative readings, whereas bIOP did not differ significantly (0.1 ± 2.1 mm Hg and 0.8 ± 1.8 mm Hg, respectively; P = .80 and P = .273, respectively). CONCLUSIONS The bIOP readings before and after LASIK and small-incision lenticule extraction were neither significantly different nor correlated with CCT. In contrast, both Goldmann IOP and Scheimpflug analyzer IOP had significant reductions postoperatively and showed significant correlation with CCT preoperatively.
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Affiliation(s)
- Kai-Jung Chen
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Akram Joda
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Riccardo Vinciguerra
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Ashkan Eliasy
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA.
| | - Shervin Mir Mohi Sefat
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Daniel Kook
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Brendan Geraghty
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Cynthia J Roberts
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
| | - Ahmed Elsheikh
- From the School of Engineering (Chen, Joda, Eliasy, Geraghty, Elsheikh), University of Liverpool and the St. Paul's Eye Unit (Vinciguerra), Royal Liverpool and Broadgreen University Hospital, Liverpool, and the NIHR Biomedical Research Centre for Ophthalmology (Elsheikh), Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom; the College of Engineering (Joda), King Faisal University, Al-Ahsa, Kingdom of Saudi Arabia; Smile Eye Clinic (Sefat, Kook) and the Department of Ophthalmology (Kook), Ludwig-Maximilians-University, Munich, Germany; the Department of Ophthalmology & Visual Science (Roberts), Department of Biomedical Engineering, Ohio State University, Columbus, Ohio, USA
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Lee SY, Bae HW, Kwon HJ, Seong GJ, Kim CY. Utility of Goldmann applanation tonometry for monitoring intraocular pressure in glaucoma patients with a history of laser refractive surgery. PLoS One 2018; 13:e0192344. [PMID: 29401477 PMCID: PMC5798809 DOI: 10.1371/journal.pone.0192344] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 01/21/2018] [Indexed: 11/18/2022] Open
Abstract
The utility of Goldmann applanation tonometry (GAT) for monitoring intraocular pressure (IOP) in open-angle glaucoma (OAG) patients with a history of laser refractive surgery was investigated by comparing IOP fluctuations measured using GAT and dynamic contour tonometry (DCT) on the same day. In this retrospective study, patients were divided into one of two subgroups according to IOP fluctuation values using GAT: 43 eyes in the low IOP fluctuation group (LIFG [GAT fluctuation ≤1.7 mmHg]); and 55 eyes in the high IOP fluctuation group (HIFG [GAT fluctuation >1.7 mmHg]). IOP fluctuation was defined as the standard deviation of all IOP values during follow-up. IOP parameters using GAT were compared with those of DCT. Correlation analyses were performed among IOP parameters, and between IOP fluctuation and associated factors including central corneal thickness, corneal curvature, and axial length. All IOP parameters demonstrated significantly high values in the HIFG compared with those in the LIFG. Mean and peak IOP using DCT were significantly higher than those using GAT in both groups. However, there were no significant differences in IOP fluctuation and reduction using both tonometry methods in the HIFG (p = 0.946 and p = 0.986, respectively). Bland-Altman analysis revealed similar fluctuations using GAT and DCT. In multivariate analyses, there was a significant correlation between fluctuations using GAT and DCT in the HIFG (p = 0.043). These results suggest that IOP monitoring using GAT is a reliable method of monitoring IOP change in glaucoma patients with a history of laser refractive surgery, especially those exhibiting high IOP fluctuation. Nevertheless, several factors, including central corneal thickness, corneal curvature, and axial length, should be considered when using GAT for IOP monitoring.
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Affiliation(s)
- Sang Yeop Lee
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Hyoung Won Bae
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Hee Jung Kwon
- Department of Ophthalmology, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Gong Je Seong
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
| | - Chan Yun Kim
- Department of Ophthalmology, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
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15
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Abstract
PURPOSE OF REVIEW Given the popularity of keratorefractive surgery, and an aging populous of patients who have undergone these procedures, there is an increasing need for updated management protocols. This is particularly relevant for patients with chronic progressive diseases such as glaucoma, due to the variety of related diagnostic and management challenges inherent to these diseases. Here, we will review the current literature to provide an update on the management of patients with glaucoma who are undergoing, or have had laser ablative refractive surgery. Preoperative testing and eligibility considerations, intraoperative factors, and postoperative observation and follow-up will be discussed. RECENT FINDINGS Intraoperative intraocular pressure (IOP) rise during flap creation is associated with low risk of acute complications, and furthermore do not appear to have significant long term effects. Modern technologies have improved our ability to determine accurate IOP after refractive surgery despite postoperative changes in corneal architecture. Furthermore, advances in structural imaging allow for earlier detection of even subtle glaucomatous nerve damage. SUMMARY Although glaucoma remains a relative contraindication to refractive surgery, it is a safe procedure for many patients with appropriate perioperative management and follow-up. Advancements in diagnostic modalities have allowed for earlier detection of glaucomatous disease, and subsequent earlier intervention when appropriate. Standardized diagnostic algorithms and rigorous perioperative assessment are critical to safe management of glaucoma patients undergoing refractive corneal surgery.
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16
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The Effect of Corneal Refractive Surgery on Glaucoma. J Ophthalmol 2017; 2017:8914623. [PMID: 28491472 PMCID: PMC5401744 DOI: 10.1155/2017/8914623] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 03/09/2017] [Indexed: 11/17/2022] Open
Abstract
Laser-assisted refractive procedures have become very popular in the last two decades. As a result, a "generation" of patients with altered corneal properties is emerging. These patients will require both cataract extraction and glaucoma follow-up in the future. Since the glaucoma examination largely depends on the corneal properties, the reshaped postrefractive surgery cornea poses a challenge in the diagnosis, follow-up, and management of the glaucomatous patient. In order to overcome this problem, every patient who is planned to undergo corneal refractive surgery must have a thorough glaucoma examination in order for the ophthalmologist to be able to monitor their patients for possible glaucoma development and/or progression. Some examinations such as tonometry are largely affected by the corneal properties, while others such as the evaluation of the structures of the posterior pole remain unaffected. However, the new imaging modalities of the anterior segment in combination with the most recent advances in tonometry can accurately assess the risk for glaucoma and the need for treatment.
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17
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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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18
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Hon Y, Chen GZ, Lu SH, Lam DCC, Lam AKC. High myopes have lower normalised corneal tangent moduli (less ‘stiff’ corneas) than low myopes. Ophthalmic Physiol Opt 2016; 37:42-50. [DOI: 10.1111/opo.12335] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 09/22/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Ying Hon
- School of Optometry; Hong Kong Polytechnic University; Hong Kong Hong Kong
| | - Guo-Zhen Chen
- Department of Mechanical and Aerospace Engineering; Hong Kong University of Science and Technology; Hong Kong
| | - Shu-Hao Lu
- Department of Mechanical and Aerospace Engineering; Hong Kong University of Science and Technology; Hong Kong
| | - David C. C. Lam
- Department of Mechanical and Aerospace Engineering; Hong Kong University of Science and Technology; Hong Kong
| | - Andrew K. C. Lam
- School of Optometry; Hong Kong Polytechnic University; Hong Kong Hong Kong
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Zhang J, Zheng L, Zhao X, Xu Y, Chen S. Corneal biomechanics after small-incision lenticule extraction versus Q-value-guided femtosecond laser-assisted in situ keratomileusis. J Curr Ophthalmol 2016; 28:181-187. [PMID: 27830201 PMCID: PMC5093843 DOI: 10.1016/j.joco.2016.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 08/02/2016] [Accepted: 08/06/2016] [Indexed: 11/16/2022] Open
Abstract
Purpose The aim of this study was to compare the changes in corneal biomechanical properties following small-incision lenticule extraction (SMILE) versus Q-value–guided femtosecond laser-assisted in situ keratomileusis (Q-FS-LASIK). Methods In this prospective comparative study, patients with a sphere plus cylinder measurement of less than −10.00 D and cylinder measurement of less than −5.00 D were included in the study. A total of 160 patients (160 eyes) with myopia and myopic astigmatism were divided into the two groups, with 80 patients (80 eyes) allocated to SMILE and 80 patients (80 eyes) allocated to Q-FS-LASIK. Corneal hysteresis (CH) and the corneal resistance factor (CRF) were quantitatively assessed using the Ocular Response Analyzer (ORA) preoperatively and at 1 day, 2 weeks, and 1 and 3 months postoperatively. Results Both types of surgery were associated with statistically significant decreases in CH and the CRF at postoperative day 1 (both P < 0.01). In both groups, the decreases subsequently stabilized with no further deteriorations compared to postoperative day 1 (P > 0.05). Both groups showed similar biomechanical changes at each time point (all P > 0.05). Conclusions Both SMILE and Q-FS-LASIK resulted in a decrease in CH and the CRF at postoperative 1 day, with the decreases stabilizing after this point. There were no significant differences between the short term effects of SMILE and Q-FS-LASIK on corneal biomechanical properties.
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Affiliation(s)
- Jun Zhang
- HangZhou Bright Vision Hospital, ZheJiang Province, China
| | - Li Zheng
- HangZhou Bright Vision Hospital, ZheJiang Province, China
| | - Xia Zhao
- HangZhou Bright Vision Hospital, ZheJiang Province, China
| | - Yang Xu
- HangZhou Bright Vision Hospital, ZheJiang Province, China
| | - Shu Chen
- HangZhou Bright Vision Hospital, ZheJiang Province, China
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Corneal Biomechanics Determination in Healthy Myopic Subjects. J Ophthalmol 2016; 2016:2793516. [PMID: 27525109 PMCID: PMC4972914 DOI: 10.1155/2016/2793516] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/22/2016] [Accepted: 06/28/2016] [Indexed: 11/25/2022] Open
Abstract
Purpose. To determine the corneal biomechanical properties by using the Ocular Response Analyzer™ and to investigate potential factors associated with the corneal biomechanics in healthy myopic subjects. Methods. 135 eyes from 135 healthy myopic subjects were included in this cross-sectional observational study. Cornea hysteresis (CH), corneal resistance factor (CRF), cornea-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure (IOPg) were determined with the Reichert Ocular Response Analyzer (ORA). Univariate and multivariate regression analyses were performed to investigate factors associated with corneal biomechanics. Results. The mean CH and CRF were 9.82 ± 1.34 mmHg and 9.64 ± 1.57 mmHg, respectively. In univariate regression analysis, CH was significantly correlated with axial length, refraction, central corneal thickness (CCT), and IOPg (r = −0.27, 0.23, 0.45, and 0.21, resp.; all with p ≤ 0.015), but not with corneal curvature or age; CRF was significantly correlated with CCT and IOPg (r = 0.52 and 0.70, resp.; all with p < 0.001), but not with axial length/refraction, corneal curvature, or age. In multivariate regression analysis, axial length, IOPcc, and CCT were found to be independently associated with CH, while CCT and IOPg were associated with CRF. Conclusions. Both CH and CRF were positively correlated with CCT. Lower CH but not CRF was associated with increasing degree of myopia. Evaluation of corneal biomechanical properties should take CCT and myopic status into consideration.
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