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Lei CS, Lin X, Ning R, Yu J, Huang X, Li K, Wang Y, Savini G, Schiano-Lomoriello D, Zhou X, Huang J. Repeatability and Interobserver Reproducibility of a Swept-Source Optical Coherence Tomography for Measurements of Anterior, Posterior, and Total Corneal Power. Ophthalmol Ther 2023; 12:3263-3279. [PMID: 37787889 PMCID: PMC10640522 DOI: 10.1007/s40123-023-00815-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/05/2023] [Indexed: 10/04/2023] Open
Abstract
INTRODUCTION The aim of this work is to evaluate the intraobserver repeatability and interobserver reproducibility of corneal power measurements obtained with a swept-source optical coherence tomographer (CASIA 2, Tomey, Japan) in healthy subjects. METHODS A total of 67 right eyes from 67 healthy subjects were enrolled. Two experienced observers measured each eye three times consecutively with the CASIA 2. Corneal power values were recorded as simulated keratometry, anterior, posterior, and total corneal power. Parameters were flattest keratometry (Kf), steepest keratometry (Ks), mean keratometry (Km), astigmatism magnitude, astigmatism power vectors J0 and J45. Intraobserver repeatability and interobserver reproducibility of the CASIA 2 were assessed by the within-subject standard deviation (Sw), test-retest repeatability (TRT), coefficients of variation (CoV), and intraclass correlation coefficients (ICCs). Double-angle plots were used for astigmatism vector analysis. RESULTS The CASIA 2 had high repeatability for all corneal power values, with Sw values ≤ 0.17 diopters (D), TRT ≤ 0.46 D, and ICCs ranging from 0.866 to 0.998. Interobserver reproducibility was also high, showing all Sw values ≤ 0.10 D, TRT ≤ 0.27 D, and ICCs ≥ 0.944. The reproducibility of the average of three consecutive measurements (Sw 0.01-0.10 D, TRT 0.03-0.27 D, ICC 0.944-0.998) was higher than the reproducibility of single measurements (Sw 0.01-0.17 D, TRT 0.03-0.47 D, ICC 0.867-0.996). CONCLUSIONS The CASIA 2 showed high intraobserver repeatability and interobserver reproducibility for anterior, posterior, and total corneal power measurements in 6.0-mm diameter area. In addition, we suggest that using the average of three consecutive measurements can improve reproducibility between observers, compared to single measurements only.
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Affiliation(s)
- Chak Seng Lei
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xuanqiao Lin
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Rui Ning
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Jinjin Yu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xiaomin Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Kexin Li
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yiran Wang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | | | | | - Xingtao Zhou
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China.
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
| | - Jinhai Huang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, No. 19 Baoqing Road, Xuhui District, Shanghai, 200031, China.
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
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Chetty E. Multivariate analysis of refractive state in eyes with keratoconus. BMJ Open Ophthalmol 2023; 8:e001344. [PMID: 37580104 PMCID: PMC10432643 DOI: 10.1136/bmjophth-2023-001344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 08/01/2023] [Indexed: 08/16/2023] Open
Abstract
OBJECTIVE To demonstrate a multivariate method of analysis of the short-term variation of refractive state in keratoconus (KC) patients. METHODS AND ANALYSIS In this observational study, 19 eyes with KC and 19 healthy control eyes were measured. The study included both male and female participants and the mean age was 23.6 years (range 18-34 years) and 23.2 years (range 22-26 years) for KC and control participants, respectively. Forty consecutive autorefractor measurements were taken for each participant and the short-term variation thereof was analysed using multivariate methods of analysis. RESULTS AND CONCLUSION Short-term variation of refractive state is greater in eyes with KC than in healthy control eyes and variation increases with severity of disease. A novel finding was that there was much more ortho-astigmatic and oblique-astigmatic variation seen in KC eyes than in control eyes which had predominately stigmatic variation. Refractive state is described by three components, namely, sphere, cylinder and axis. Although it is multivariate in nature, it is often analysed using univariate statistical methods. In diseases such as KC, where early diagnosis is crucial for a good prognosis, it is necessary that researchers endeavour to investigate the disease from different perspectives to fully understand the nature of the disease. This paper comprehensively demonstrates the multivariate statistical methods of analysis of refractive data. The implementation of this analysis provides insight into the short-term variation of refractive data in healthy and keratoconic eyes, and these findings have not been demonstrated before using univariate statistics.
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Affiliation(s)
- Elizabeth Chetty
- Department of Optometry, University of Johannesburg, Auckland Park, South Africa
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Tosun M, Bozali E, Yalınbaş Yeter D, Apa AS. Analysis of corneal topographic and densitometric properties in patients receiving systemic isotretinoin therapy. Cutan Ocul Toxicol 2023; 42:19-24. [PMID: 36433791 DOI: 10.1080/15569527.2022.2152042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate dry eye parameters, corneal topographic features, corneal densitometric changes, and anterior segment parameters in patients receiving systemic isotretinoin treatment. METHODS This prospective cross-sectional study included 66 eyes of 33 patients who were started on oral isotretinoin therapy for severe acne vulgaris. All patients were evaluated in terms of ocular surface tests such as tear break-up time (TBUT) and Schirmer-1 and were asked to fill in the ocular surface disease index (OSDI) questionnaire. Corneal densitometric and topographic measurements were obtained using the Scheimpflug imaging system. RESULTS The mean age of the patients was 19.9 ± 1.6 years, and 21 (63.6%) of the participants were female. The mean OSDI score was significantly higher in the third month than before treatment (20.05 ± 19.38, vs. 26.96 ± 22.94, p = 0.00, respectively). The mean values of the TBUT test were significantly lower in the third month than before treatment (9.06 ± 4.40 sec, vs. 10.71 ± 4.61 sec, p = 0.02, respectively). Mean scores of the Schirmer 1 test showed no statistically significant difference between before treatment and the third month (16.08 ± 8.40 mm, vs. 16.08 ± 8.50 mm, p = 1, respectively). There was no statistically significant difference between before treatment and the third month in the majority of the densitometry measurements in concentric zones. However, the difference tended to be significant between the groups concerning posterior zone 0-2 mm (11.01 ± 0.85 GSU vs. 10.62 ± 0.89 GSU, p = 0.006). The RMS LOAs (front), RMS Total (Total), RMS LOAs Total (Total), RMS HOAs Total (Total), Kmax, CCT, and CoV values were significantly higher in the third month than before treatment (p < 0.05 for all). CONCLUSIONS The dermatology specialists should be aware of the ocular complications of systemic isotretinoin therapy. Therefore, a complete ophthalmologic examination for the prompt apprehension and management of ocular involvement is essential in patients under isotretinoin therapy to increase ocular comfort and adherence to the therapy.
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Affiliation(s)
- Mustafa Tosun
- Department of Dermatology, Sivas Cumhuriyet University Faculty of Medicine, Sivas, Turkey
| | - Erman Bozali
- Department of Ophthalmology, Sivas Cumhuriyet University Faculty of Medicine, Sivas, Turkey
| | - Duygu Yalınbaş Yeter
- Department of Ophthalmology, Sivas Cumhuriyet University Faculty of Medicine, Sivas, Turkey
| | - Anıl Selim Apa
- Department of Ophthalmology, Sivas Cumhuriyet University Faculty of Medicine, Sivas, Turkey
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Zorto AD, Sharif MS, Wall J, Brahma A, Alzahrani AI, Alalwan N. An innovative approach based on machine learning to evaluate the risk factors importance in diagnosing keratoconus. INFORMATICS IN MEDICINE UNLOCKED 2023. [DOI: 10.1016/j.imu.2023.101208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
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Alshehri O, Abdelaal AM, Abudawood G, Khan MA, Alsharif S, Hijazi H, AlQassimi A. Normative Values for Corneal Tomography and Comparison of Both Eyes in Young Saudi Males with 20/20 Vision Using Pentacam-HR Scheimpflug Imaging. Clin Ophthalmol 2022; 16:2631-2637. [PMID: 35992566 PMCID: PMC9385131 DOI: 10.2147/opth.s376411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/03/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose Anterior segment evaluation using Scheimpflug imaging with the Pentacam scanner allows the acquisition of a plethora of information. It aids in screening and diagnosing corneal pathologies and determining suitability for keratorefractive procedures. This research has significant benefits in terms of establishing normative tomographic values, which is crucial in countries where Keratoconus (KC) is more prevalent, especially among young age group, along with aiding future research in the field of refractive surgery by providing relevant normative data. Methods A retrospective review of digital corneal tomography images for a group of medically and ophthalmologically free males aged between 18 and 21 years with 20/20 unaided distant visual acuity was performed. Results A total of 1272 subjects (2544 eyes) were included. Findings revealed a mean maximal corneal curvature (Kmax) of 42.91 ± 1.40D (range 36.90–47.80D). The mean flat keratometry (K1) was 41.87 ± 1.31D (range 36.00–46.40D). The mean steep keratometry (K2) was 42.66 ± 1.35D (range 36.70–47.60D). The mean corneal astigmatism (CA) was 0.79 ± 0.37D (range 0.00D-2.30D). The mean central corneal thickness (CCT) was 558.53 ± 33.84 μm (range 421–677 μm). The mean thinnest corneal location thickness (TCLT) was 551.64 ± 34.08 μm (range 417–669μm). The mean corneal diameter (CD) and anterior chamber depth (ACD) were 12.13 ± 0.39 mm (range 10.50–13.60 mm) and 3.12 ± 0.29 mm (range 2.08–4.08 mm), respectively. The median differences between both eyes of the same subject were as follows: kmax difference of 0.20D (IQR 0.1–0.4); K1, K2 and CA difference of 0.20D (IQR 0.1–0.3) for all 3 parameters; CCT and TCLT difference of 5.00 μm (IQR 3.0–9.0) and 6.00 μm (IQR 3.0–10.0), respectively; CD difference of 0.10 mm (IQR 0.0–0.1); and ACD difference of 0.04 (IQR 0.02–0.06). Conclusion We believe our data can aid in establishing normative tomographic values and acceptable differences between both eyes. Our data may also help detect subtle corneal pathology and be useful for researchers and innovators in the field of ophthalmology.
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Affiliation(s)
- Omar Alshehri
- Ophthalmology Department, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
| | - Ahmed M Abdelaal
- Ophthalmology Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
- Correspondence: Ahmed M Abdelaal, Ophthalmology Department, Prince Sultan Military Medical City, Riyadh, Saudi Arabia, Tel +966 56 371 8789, Email
| | - Ghufran Abudawood
- Ophthalmology Department, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
| | - Muhammad A Khan
- Epidemiology and Public Health Department, King Saud Bin Abdulaziz University, Jeddah, Saudi Arabia
| | - Saud Alsharif
- Faculty of Medicine, Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia
| | - Hassan Hijazi
- Ophthalmology Department, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
| | - AlBaraa AlQassimi
- Ophthalmology Department, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia
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Turner JM, Purslow C, Murphy PJ. Comparison of Javal-Schiøtz keratometer, Orbscan IIz and Pentacam topographers in evaluating anterior corneal topography. Clin Exp Optom 2022:1-8. [PMID: 35614035 DOI: 10.1080/08164622.2022.2067470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
CLINICAL RELEVANCE Inter-instrument variation in anterior corneal shape (ACS) measurement has a consequence for ocular clinical practice. BACKGROUND To consider inter-instrument variability in keratometry measurements across the ACS and to explore instrument protocols for determining ACS keratometric analogues (KAs). METHODS Mean keratometry/KAs of the right eye were recorded using Javal-Schiøtz keratometer (J-S), Orbscan IIz and Pentacam from 124 subjects (78 females; mean ± SD age: 24.71 ± 6.61 years). Mean radii of curvature were obtained for 1-mm wide annular zones extending up to 6 mm (horizontally) and 4 mm (vertically) from the apex for Orbscan and Pentacam. Zonal mean radius of curvature was calculated by averaging keratometry values for all measured points within the zone. RESULTS KA (mean ± SD): Horizontal: Orbscan (7.80 ± 0.31 mm) and J-S (7.82 ± 0.29 mm) were not significantly different (p = 0.072). Pentacam (7.86 ± 0.29 mm) was significantly flatter than J-S (p < 0.001) and Orbscan (p < 0.001). Vertical: Orbscan (7.64 ± 0.31 mm) was significantly steeper than J-S (7.67 ± 0.29 mm, p < 0.005) and Pentacam (7.70 ± 0.29 mm, p < 0.001). Pentacam was significantly flatter than J-S (p < 0.001) and significant flatter than Orbscan across the entire profile (1-4 mm zones horizontal and vertical, p < 0.001). LoAs (CI): J-S/Orbscan: ±0.75 mm (0.05-0.18); J-S/Pentacam: ±0.72 mm (0.01-0.12); Pentacam/Orbscan: ±0.16 mm (0.04-0.08). There was a +0.03 mm positive bias for Orbscan compared to J-S, +0.06 mm positive bias for Orbscan compared to Pentacam and -0.03 mm negative bias for Pentacam compared to J-S. CONCLUSIONS Algorithms used by Orbscan and Pentacam to solve the peripheral paraxial ray problem produce significantly different KAs. Instrument-specific KAs cannot be used inter-changeably between instruments. Differences in KA between instruments are not significant for ocular surgery, but may influence rigid contact lens fitting. Pentacam measures flatter than Orbscan and J-S.
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Affiliation(s)
- Jennifer M Turner
- Division of Optometry, Department of Health and Wellbeing, University of the West of England, Bristol, UK.,School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Christine Purslow
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Paul J Murphy
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
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Chen S, Zhang Q, Savini G, Zhang S, Huang X, Yu J, Wang Y, Ning R, Huang J, Tu R. Comparison of a New Optical Biometer That Combines Scheimpflug Imaging With Partial Coherence Interferometry With That of an Optical Biometer Based on Swept-Source Optical Coherence Tomography and Placido-Disk Topography. Front Med (Lausanne) 2022; 8:814519. [PMID: 35223885 PMCID: PMC8866319 DOI: 10.3389/fmed.2021.814519] [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: 11/13/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
PURPOSE To evaluate measurement precision and to compare the Pentacam AXL (Oculus Optikgeräte, Wetzlar, German), a new optical biometer based on Scheimpflug imaging and partial coherence interferometry (PCI) with that of the OA-2000 biometer (Tomey, Nagoya, Japan), which combines swept-source optical coherence tomography (SS-OCT) and Placido-disk topography. METHODS Axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AQD), mean keratometry (Km), astigmatism vectors J0, J45, and corneal diameter (CD) were measured in triplicate by two technical operators. Within-subject standard deviation (Sw), repeatability and reproducibility (2.77 Sw), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were used to assess the Pentacam AXL intra-observer repeatability and inter-observer reproducibility. Paired t-test and Bland-Altman plots were used to determine the agreement between the two biometers. RESULTS The new optical biometer had high intra-observer repeatability [all parameters evaluated had low CoV (<0.71%) and high ICC (>0.88)]. Inter-observer reproducibility was also excellent, with high ICC (>0.95) and low CoV (<0.52%). The 95% LoA between the new biometer and OA-2000 were insignificant for most of the parameters evaluated, especially for AL. However, the measurement agreement was moderate for CCT. CONCLUSIONS Intra-observer repeatability and inter-observer reproducibility were excellent for all parameters evaluated using the new optical biometer based on Scheimpflug imaging and PCI. There was a high agreement between the two devices and hence could be clinically interchangeable for the measurement of most ocular parameters.
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Affiliation(s)
- Shihao Chen
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Qiaoyue Zhang
- Department of Ophthalmology, Air Force Medical Center, Beijing, China
| | | | - Shuangzhe Zhang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Xiaomin Huang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Jinjin Yu
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Yirang Wang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Rui Ning
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
| | - Jinhai Huang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China.,Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University; Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Ruixue Tu
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University; State Key Laboratory of Optometry, Ophthalmology and Vision Science, Wenzhou, China
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Cao K, Verspoor K, Sahebjada S, Baird PN. Accuracy of Machine Learning Assisted Detection of Keratoconus: A Systematic Review and Meta-Analysis. J Clin Med 2022; 11:jcm11030478. [PMID: 35159930 PMCID: PMC8836961 DOI: 10.3390/jcm11030478] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/10/2022] [Accepted: 01/13/2022] [Indexed: 12/26/2022] Open
Abstract
(1) Background: The objective of this review was to synthesize available data on the use of machine learning to evaluate its accuracy (as determined by pooled sensitivity and specificity) in detecting keratoconus (KC), and measure reporting completeness of machine learning models in KC based on TRIPOD (the transparent reporting of multivariable prediction models for individual prognosis or diagnosis) statement. (2) Methods: Two independent reviewers searched the electronic databases for all potential articles on machine learning and KC published prior to 2021. The TRIPOD 29-item checklist was used to evaluate the adherence to reporting guidelines of the studies, and the adherence rate to each item was computed. We conducted a meta-analysis to determine the pooled sensitivity and specificity of machine learning models for detecting KC. (3) Results: Thirty-five studies were included in this review. Thirty studies evaluated machine learning models for detecting KC eyes from controls and 14 studies evaluated machine learning models for detecting early KC eyes from controls. The pooled sensitivity for detecting KC was 0.970 (95% CI 0.949–0.982), with a pooled specificity of 0.985 (95% CI 0.971–0.993), whereas the pooled sensitivity of detecting early KC was 0.882 (95% CI 0.822–0.923), with a pooled specificity of 0.947 (95% CI 0.914–0.967). Between 3% and 48% of TRIPOD items were adhered to in studies, and the average (median) adherence rate for a single TRIPOD item was 23% across all studies. (4) Conclusions: Application of machine learning model has the potential to make the diagnosis and monitoring of KC more efficient, resulting in reduced vision loss to the patients. This review provides current information on the machine learning models that have been developed for detecting KC and early KC. Presently, the machine learning models performed poorly in identifying early KC from control eyes and many of these research studies did not follow established reporting standards, thus resulting in the failure of these clinical translation of these machine learning models. We present possible approaches for future studies for improvement in studies related to both KC and early KC models to more efficiently and widely utilize machine learning models for diagnostic process.
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Affiliation(s)
- Ke Cao
- Centre for Eye Research Australia, Melbourne, VIC 3002, Australia; (K.C.); (S.S.)
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, VIC 3002, Australia
| | - Karin Verspoor
- School of Computing Technologies, RMIT University, Melbourne, VIC 3000, Australia;
- School of Computing and Information Systems, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Srujana Sahebjada
- Centre for Eye Research Australia, Melbourne, VIC 3002, Australia; (K.C.); (S.S.)
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, VIC 3002, Australia
| | - Paul N. Baird
- Department of Surgery, Ophthalmology, The University of Melbourne, Melbourne, VIC 3002, Australia
- Correspondence: ; Tel.: +61-3-9929-8613
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Yang K, Gu Y, Xu L, Fan Q, Zhu M, Wang Q, Yin S, Zhang B, Pang C, Ren S. Distribution of pediatric keratoconus by different age and gender groups. Front Pediatr 2022; 10:937246. [PMID: 35923788 PMCID: PMC9339668 DOI: 10.3389/fped.2022.937246] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/30/2022] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To evaluate the distribution of pediatric keratoconus patients and the disease severity based on different age and gender groups in China. MATERIALS AND METHODS A total of 446 keratoconus eyes in 266 pediatric patients from January 2019 to January 2022 were included in the cross-sectional study. The clinical findings and severity of keratoconus were recorded and Kruskal-Wallis test, chi-squared test, and Cochran-Mantel-Haenszel (CMH) test were used to compare the parameters between different gender and age groups. RESULTS The male/female ratio was 353/93 (3.8:1), and the median age was 16 years (range: 6-17 years). Male patients were statistically younger than female patients (P = 0.041). The male/female ratio decreased with age (P for trend = 0.011). The distribution of the topographic keratoconus classification (TKC) stage was significantly different between gender and age groups (all P < 0.05). Male patients had a higher ratio of advanced keratoconus eyes (TKC ≥ 3) than female patients (P < 0.001), and CMH analysis indicated that being a male was a risk factor for advanced keratoconus after controlling for age (odds ratio: 2.581, P < 0.001). CONCLUSION Male keratoconus patients were younger, with a higher ratio of advanced keratoconus than female patients in the Chinese pediatric patients evaluated. Multicenter studies with larger sample sizes are necessary in the future.
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Affiliation(s)
- Kaili Yang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Yuwei Gu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Liyan Xu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Qi Fan
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Meng Zhu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Qing Wang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Shanshan Yin
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Bo Zhang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Chenjiu Pang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
| | - Shengwei Ren
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, Zhengzhou, China
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Scaglioni TDCM, Miranda BA, Rodrigues ID, Reis PPLD. Associação entre alergia ocular leve e ceratocone em crianças. REVISTA BRASILEIRA DE OFTALMOLOGIA 2021. [DOI: 10.37039/1982.8551.20210016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Sharma A, Batra A. Assessment of precision of astigmatism measurements taken by a sweptsource optical coherence tomography biometer - IOLMaster 700. Indian J Ophthalmol 2021; 69:1760-1765. [PMID: 34146024 PMCID: PMC8374785 DOI: 10.4103/ijo.ijo_2776_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purpose: To assess the repeatability of ocular measurements, particularly astigmatism, taken using the latest version of an swept-source optical coherence tomography (SS-OCT) device, IOLMaster 700. Methods: This prospective observational study done in a private eye care centre. Study included 213 eyes of 152 patients diagnosed with cataract. Axial length (AL), Anterior corneal astigmatism (ΔK), Total corneal astigmatism (ΔTK), Aqueous depth (AD), Lens thickness (LT), Iris barycentre distance (IBD) and White to white distance (WTW) were analysed; three measurements were taken for each patient in the same sitting by the same examiner in an undilated state using the SS-OCT device. Repeatability was analysed using intraclass coefficient (ICC) and coefficient of variation (CV) measures, and astigmatism values were transformed into vector components (J0/J45) and categorised based on magnitude. Results: Astigmatism vector components (J0/J45) showed poor repeatability (ICC < 0.5 and CV > 0), while iris coordinates (IBD) and astigmatism magnitude had good correlation (ICC > 0.9) but more variations between the readings which was least for magnitude ≥ 1.5D; however, rest of the parameters demonstrated excellent repeatability (ICC > 0.9 with P value < 0.05). Conclusion: IOLMaster 700 demonstrated good reliability for the parameters measured, although, for astigmatism and iris barycentre distance, more number of readings and cross reference with other devices may be required to get clinically accurate results.
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Affiliation(s)
- Ajay Sharma
- Department of Cataract and Refractive, Amber Eye Care and Micro Surgery Centre, Thane, Maharashtra, India
| | - Akanksha Batra
- Department of Cataract and Refractive, Amber Eye Care and Micro Surgery Centre, Thane, Maharashtra, India
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12
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Gilevska F, Biscevic A, Popovic Suic S, Bohac M, Patel S. Are changes in visual acuity and astigmatism after corneal cross-linking (CXL) in keratoconus predictable? Graefes Arch Clin Exp Ophthalmol 2021; 259:2259-2268. [PMID: 33885984 DOI: 10.1007/s00417-021-05173-5] [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: 09/10/2020] [Revised: 03/05/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022] Open
Abstract
PURPOSE To evaluate changes in corrected distance visual acuity (CDVA), ratio of anterior and posterior corneal radii over the thinnest region of the cornea (ARC/PRC), and astigmatism after cross-linking (CXL) in keratoconus. METHODS Subjective refraction and ARC/PRC (using Pentacam™) were monitored over 1 year in (I) keratoconus treated with routine CXL (n = 53), (II) relatively stable keratoconus (n = 23), and (III) age/gender matched controls (n = 24). RESULTS CDVA (median, mode, interquartile range) improved significantly in group I, compared with groups II and III (p < 0.05), from 0.45 (0.60, 0.20-0.63) to 0.80 (0.95, 0.60-0.95); change in CDVA was associated with preop CDVA (p < 0.01 at all times postop). ARC/PRC (mean ± sd, 95% CI) changed from 1.362 (± 0.048, 1.347-1.377) to 1.425 (± 0.073, 1.401-1.449). CDVA and ARC/PRC remained stable in II and III. Significant relationships were revealed between logCDVA and ARC/PRC in I and II (at 12 months, I rs = - 0.464, II rs - 0.449) and logCDVA at postop(y), log CDVA at preop(x1), and ARC/PRC at preop(x2) in I (at 12 months, y = 0.356x1 - 1.312x2 + 1.806, r21 = 0.494, r22 = 0.203). Astigmatic power (mean ± sd, 95% CI) improved from - 3.10DC (± 1.52, - 3.55 to - 2.66) to - 2.53DC (± 1.24, - 2.90 to - 2.17) in I, and worsened from - 1.27DC (± 1.32, - 1.81 to - 0.73) to - 1.61DC (± 1.28, - 2.13 to - 1.09) in II. Vector analysis revealed in group I (a) the power of the surgically induced astigmatism (SIA) was linked to astigmatic power at preop and (b) the difference between the axis of astigmatism at preop(ø) and the axis of the SIA was linked to ø. CONCLUSION CXL improved CDVA, increased the ARC/PRC ratio, and modified the association between CDVA and ARC/PRC. The change in CDVA was linked to preop CDVA and ARC/PRC values. The association between SIA and preop astigmatism implies there is not a simple cause and effect relationship with CXL.
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Affiliation(s)
- Fanka Gilevska
- Eye Clinic Sistina Oftalmologija, Skupi 5A, Skopje, Republic of North Macedonia.
| | | | | | - Maja Bohac
- Specialty Eye Hospital "Svjetlost", Zagreb, Croatia.,School of Medicine, University of Rijeka, Rijeka, Croatia
| | - Sudi Patel
- Specialty Eye Hospital "Svjetlost", Zagreb, Croatia
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13
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Molina‐martín A, Piñero DP, Caballero MT, Fez D, Camps VJ. Comparative analysis of anterior corneal curvature and astigmatism measurements obtained with three different devices. Clin Exp Optom 2021; 103:618-624. [DOI: 10.1111/cxo.13002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/04/2019] [Accepted: 10/09/2019] [Indexed: 11/28/2022] Open
Affiliation(s)
- Ainhoa Molina‐martín
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
- Department of Ophthalmology, Vithas Medimar International Hospital, Alicante, Spain,
| | - María T Caballero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - Dolores Fez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - Vicent J Camps
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
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14
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Oliveira CM, Ribeiro C, Franco S. Corneal imaging with slit‐scanning and Scheimpflug imaging techniques. Clin Exp Optom 2021; 94:33-42. [DOI: 10.1111/j.1444-0938.2010.00509.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
| | - Celina Ribeiro
- Centre/Department of Physics, University of Minho, Portugal
E‐mail:
| | - Sandra Franco
- Centre/Department of Physics, University of Minho, Portugal
E‐mail:
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15
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Falavarjani KG, Modarres M, Joshaghani M, Azadi P, Afshar AE, Hodjat P. Interocular differences of the Pentacam measurements in normal subjects. Clin Exp Optom 2021; 93:26-30. [DOI: 10.1111/j.1444-0938.2009.00446.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
| | - Mehdi Modarres
- Eye Research Center, Iran University of Medical Sciences, Tehran, Iran E‐mail:
| | - Mahmoud Joshaghani
- Eye Research Center, Iran University of Medical Sciences, Tehran, Iran E‐mail:
| | - Pejvak Azadi
- Eye Research Center, Iran University of Medical Sciences, Tehran, Iran E‐mail:
| | | | - Parsa Hodjat
- Eye Research Center, Iran University of Medical Sciences, Tehran, Iran E‐mail:
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16
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Hamer CA, Buckhurst H, Purslow C, Shum GL, Habib NE, Buckhurst PJ. Comparison of reliability and repeatability of corneal curvature assessment with six keratometers. Clin Exp Optom 2021; 99:583-589. [DOI: 10.1111/cxo.12329] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 05/26/2015] [Accepted: 06/21/2015] [Indexed: 11/30/2022] Open
Affiliation(s)
- Catriona A Hamer
- School of Health Professions, Faculty of Heath and Human Sciences, Plymouth University, Plymouth, UK,
| | - Hetal Buckhurst
- School of Health Professions, Faculty of Heath and Human Sciences, Plymouth University, Plymouth, UK,
| | - Christine Purslow
- School of Optometry & Vision Sciences, Cardiff University, Cardiff, UK,
| | - Gary L Shum
- School of Health Professions, Faculty of Heath and Human Sciences, Plymouth University, Plymouth, UK,
| | | | - Phillip J Buckhurst
- School of Health Professions, Faculty of Heath and Human Sciences, Plymouth University, Plymouth, UK,
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17
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Zhao J, Chen Z, Zhou Z, Ding L, Zhou X. Evaluation of the repeatability of the Lenstar and comparison with two other non‐contact biometric devices in myopes. Clin Exp Optom 2021; 96:92-9. [PMID: 22943766 DOI: 10.1111/j.1444-0938.2012.00793.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 05/29/2012] [Accepted: 06/22/2012] [Indexed: 12/23/2022] Open
Affiliation(s)
- Jing Zhao
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Zhi Chen
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Zimei Zhou
- Department of Ophthalmology, Bronx Lebanon Hospital Center, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Lan Ding
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
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18
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Łabuz G, Varadi D, Khoramnia R, Auffarth GU. Central and mid-peripheral corneal astigmatism in an elderly population: a retrospective analysis of Scheimpflug topography results. Sci Rep 2021; 11:7968. [PMID: 33846337 PMCID: PMC8041809 DOI: 10.1038/s41598-021-81772-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 01/06/2021] [Indexed: 11/24/2022] Open
Abstract
Implantation of toric intraocular lenses (IOLs) has become standard in the correction of corneal astigmatism. The IOL selection is based on keratometric measurements of the central cornea. However, mid-peripheral corneal changes may yield suboptimal correction in patients with larger pupils. This study retrospectively analyzed corneal topography data collected using a Scheimpflug device during routine clinical examinations. Of 11,953 patients, 641 met the inclusion criteria. Total corneal astigmatism was compared between five concentric zones (2–6 mm) using vector analysis. The absolute difference between astigmatism at 2 mm and 6 mm was 0.30 D (− 0.36 to 0.64), which decreased to 0.10 D (0 to 0.20) between the 5- and 6-mm zone. With-the-rule astigmatism was the most prevalent (53%), 34% had against-the-rule (ATR), and 13% had oblique. The decrease of the cylinder power with the diameter differed significantly between the three types, with ATR and oblique astigmatism being associated with the steepest change. Patients with high corneal astigmatism tend to demonstrate larger differences between the center and mid-periphery than those with low and moderate astigmatism. In conclusion, we demonstrated that central corneal astigmatism differs from that measured at the mid-periphery and that a larger difference was found in patients with ATR, oblique and high astigmatism.
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Affiliation(s)
- Grzegorz Łabuz
- David J Apple Center for Vision Research, Department of Ophthalmology, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany
| | - Dorottya Varadi
- David J Apple Center for Vision Research, Department of Ophthalmology, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany
| | - Ramin Khoramnia
- David J Apple Center for Vision Research, Department of Ophthalmology, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany
| | - Gerd U Auffarth
- David J Apple Center for Vision Research, Department of Ophthalmology, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany.
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19
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Yang K, Xu L, Fan Q, Gu Y, Zhang B, Meng F, Zhao D, Pang C, Ren S. A hospital-based study on clinical data, demographic data and visual function of keratoconus patients in Central China. Sci Rep 2021; 11:7559. [PMID: 33824422 PMCID: PMC8024332 DOI: 10.1038/s41598-021-87291-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 03/26/2021] [Indexed: 11/23/2022] Open
Abstract
China is a populous country but lacks epidemiological data on keratoconus (KC). The present study aimed to investigate the clinical data, demographic data, and visual function (VF) data of KC patients in Central China. A total of 524 KC eyes in 307 KC patients (217 bilateral and 90 unilateral) from Henan Eye Hospital were included in the current study. Demographic and VF data were assessed with questionnaires administered by well-trained staff during face-to-face interviews. Visual acuity value was examined by a qualified optometrist, and the clinical data were measured by professional clinicians. The distributions of sex, residence and education level of KC patients were compared by Chi-square tests, and the ratios of people wearing glasses and rigid gas permeable (RGP) lenses were compared by McNemar tests. General linear models/Chi-squared tests were used to compare the clinical and demographic data according to KC severity. Spearman’s correlation analysis was used to test the associations between the data and KC severity. The mean age at diagnosis was 20.98 ± 6.06 years, and males had a higher ratio of KC than females (P < 0.001). Patients in rural areas had a higher rate of KC than those in urban areas (P = 0.039), and the proportion of KC patients with a higher education level (above high school) was high (P < 0.001). A total of 68.40% of the patients reported eye rubbing and 3.52% had a positive family history. The percentage of people wearing glasses was higher than that of patients wearing RGP lenses (P < 0.001). The total VF score of KC patients was 69.35 ± 15.25. The thinnest corneal thickness (TCT) and stiffness parameter at the first applanation (SP-A1) values were inversely correlated with KC severity (P < 0.05). The mean, steep, and max keratometry (Km, Ks and Kmax) values, the RGP lens use and keratoplasty were positively correlated with KC severity (all P < 0.05). The total VF score of the eye with better VA decreased as the severity increased (r = − 0.21, P = 0.002). The present study comprehensively describes various associated features of KC patients from a tertiary hospital in Central China, providing a reference for understanding the characteristics of KC patients in China.
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Affiliation(s)
- Kaili Yang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Liyan Xu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Qi Fan
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Yuwei Gu
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Bo Zhang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Feiying Meng
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Dongqing Zhao
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Chenjiu Pang
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China
| | - Shengwei Ren
- Henan Provincial People's Hospital, Henan Eye Hospital, Henan Eye Institute, People's Hospital of Zhengzhou University, Henan University People's Hospital, 7 Weiwu Road, Zhengzhou, 450003, Henan, People's Republic of China.
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20
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Tomiyama ES, Logan AK, Richdale K. Corneal Elevation, Power, and Astigmatism to Assess Toric Orthokeratology Lenses in Moderate-to-High Astigmats. Eye Contact Lens 2021; 47:86-90. [PMID: 32568927 PMCID: PMC7749028 DOI: 10.1097/icl.0000000000000721] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2020] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Fitting philosophies for toric orthokeratology are based on elevation or corneal astigmatism, but it is unclear which is more effective. The purpose of this analysis was to further understand corneal shape and the relationship between peripheral elevation and central astigmatism in moderate-to-high astigmats. METHODS Corneal tomography was measured three times on the right eyes of 25 moderate-to-high refractive myopic astigmatic adults. Corneal astigmatism and elevation were calculated at 4-, 6-, and 8-mm chords. Subjects were fitted with toric orthokeratology lenses following the manufacturer's guidelines based on elevation. Twenty subjects completed 10 days of wear. A masked examiner assessed movement and centration via slitlamp videos and quantified treatment zone and decentration from tangential power difference tomography maps. Correlations between variables were assessed. RESULTS Average corneal astigmatism was 2.20±0.70 DC and peripheral elevation was 50.88±18.92 μm and they were strongly correlated (4 mm R2=0.96, 6 mm R2=0.92, 8 mm R2=0.86, all P<0.001). Each diopter of astigmatism equated to 25 μm of elevation at an 8-mm chord. Via slitlamp, average treatment zone area was 12.73±4.62 mm2 and 13 lenses decentered. From tomography, average treatment zone area was 7.16±2.56 mm2 and 17 were decentered. Tomography treatment zone area was negatively correlated with central corneal astigmatism (R2=0.60) and elevation at an 8-mm chord (R2=0.64, both P<0.001). CONCLUSIONS For tomography images, central corneal astigmatism was highly correlated with peripheral elevation and may be a more expedient measure for clinical use. Treatment area decreased as corneal astigmatism and elevation increased.
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Affiliation(s)
| | - Anna-Kaye Logan
- University of Houston College of Optometry, Houston, TX, USA
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21
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The Reliability of Successive Scheimpflug Imaging and Anterior Segment Optical Coherence Tomography Measurements Decreases With Increasing Keratoconus Severity. Cornea 2021; 40:1433-1439. [DOI: 10.1097/ico.0000000000002657] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 11/27/2020] [Indexed: 11/26/2022]
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22
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Yildirim Y, Ozsaygili C, Kucuk B. The short term effect of trehalose and different doses of sodium hyaluronate on anterior corneal aberrations in dry eye patients. Cutan Ocul Toxicol 2020; 40:14-20. [PMID: 33342322 DOI: 10.1080/15569527.2020.1861001] [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] [Indexed: 10/22/2022]
Abstract
AIM To evaluate the short-term effect of 0.15% sodium hyaluronate (SH), 0.20% SH, and Trehalose + 0.15% SH on anterior corneal aberrations in dry eye patients. METHODS 76 eyes of 76 dry eye patients were divided into three groups. Non-preserved 1.5 mg/mL SH was administered in group 1, non-preserved 2.0 mg/mL SH was administered in group 2, and non-preserved trehalose 30 mg/mL and 1.5 mg/mL SH was administered in group 3. Aberrometry measurements were performed before and 10 min after application of the artificial tear drop. Using the Pentacam Scheimpflug imaging system, total root mean square (RMS), lower-order aberration (LOA), higher-order aberrations (HOAs), spherical aberration (SA), trefoil, and coma aberrations were investigated. RESULTS In each group; the RMS of total, LOA, HOAs, and spherical aberration were significantly decreased after the artificial drop instillation, compared with those of them at baseline; and in groups 1 and 2, vertical trefoil term was also significantly increased, compared with those of them at baseline. According to intergroup analyzes, there was no significant outcome. CONCLUSIONS It was observed that three artificial tears reduced the anterior corneal aberrations, in a 10-min period. The short-term effect of three artificial tears on the anterior corneal aberration was similar.
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Affiliation(s)
- Yener Yildirim
- Ophthalmology Department, Kayseri City Training and Research Hospital, Kocasinan, Turkey
| | - Cemal Ozsaygili
- Ophthalmology Department, Kayseri City Training and Research Hospital, Kocasinan, Turkey
| | - Bekir Kucuk
- Ophthalmology Department, Kayseri City Training and Research Hospital, Kocasinan, Turkey
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23
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Chetty E, Rubin A. A comparison of anterior and posterior central corneal powers in eyes with and without keratoconus. AFRICAN VISION AND EYE HEALTH 2020. [DOI: 10.4102/aveh.v79i1.607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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24
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Li M, Yang D, Zhao Y, Yang W, Shang J, Zhou X, Yao P, Yang D, Lin X, Zhou X. Impact of ablation ratio on 5-year postoperative posterior corneal stability after refractive surgery: SMILE and FS-LASIK. EYE AND VISION 2020; 7:53. [PMID: 33292814 PMCID: PMC7654178 DOI: 10.1186/s40662-020-00218-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 10/20/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND To investigate the impact of the ablation ratio on 5-year postoperative posterior corneal stability in myopic eyes after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery. METHODS A prospective, nonrandomized, cohort study: 80 eyes of 43 patients underwent SMILE surgery and 63 eyes of 32 patients underwent FS-LASIK surgery at the EYE & ENT Hospital, Fudan University. Ablation ratio was defined as lenticule thickness (SMILE cases) or ablation depth (FS-LASIK cases) divided by central corneal thickness (CCT). Posterior corneal elevation changes were recorded as posterior central elevation (PCE), posterior corneal surface at thinnest point (PTE) and posterior corneal mean elevation (PME). Patients were followed up at 6-month and 5-year interval to investigate the impact of the ablation ratio on posterior corneal elevation after SMILE and FS-LASIK surgery. RESULTS PCE dropped at the 6-month follow-up for both SMILE (decreased by -1.11 ± 2.93 μm, P < 0.05) and FS-LASIK groups (decreased by -0.46 ± 3.72 μm, P < 0.05). PTE also dropped in SMILE (reduced by -2.04 ± 3.02 μm, P < 0.05) and FS-LASIK group (reduced by -1.28 ± 4.21 μm, P < 0.05) at the 6-month follow-up. Stable PCE (elevation change: SMILE -0.28 ± 4.03 μm; FS-LASIK 0.79 ± 4.13 μm, P > 0.05) and PTE (elevation change: SMILE -0.08 ± 4.28 μm; FS-LASIK 1.42 ± 3.85 μm, P > 0.05) for both groups were recorded at the 5-year follow-up compared to the 6-month visit. Ablation ratio was strongly correlated with 5-year postoperative PCE (β = 2.68 ± 1.05, P < 0.01) and PTE (β = 2.35 ± 1.17, P < 0.05). Cut-off value for 5-year postoperative raised PCE and PTE was 27.3 and 27.1%, respectively. CONCLUSIONS Ablation ratio was strongly correlated with postoperative posterior corneal elevation in a 5-year follow-up in both SMILE and FS-LASIK groups. PCE and PTE underwent slight backward displacement 6-month postoperatively and remain stable at the 5-year follow-up. Threshold of the ablation ratio for resisting forward displacement of posterior corneal surface was 27.3 and 27.1% for SMILE and FS-LASIK groups, respectively.
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Affiliation(s)
- Meiyan Li
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Danjuan Yang
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yu Zhao
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Weiming Yang
- Department of Ophthalmology and Optometry, Children's Hospital of Fudan University, Shanghai, China
| | - Jianmin Shang
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xueyi Zhou
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Peijun Yao
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Dong Yang
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xue Lin
- Department of Ophthalmology, Dalian Municipal Women and Children's Medical Center, Dalian, China.
| | - Xingtao Zhou
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China. .,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China. .,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China. .,Department of Ophthalmology and Optometry, Children's Hospital of Fudan University, Shanghai, China.
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Zhao Y, Chen D, Savini G, Wang Q, Zhang H, Jin Y, Song B, Ning R, Huang J, Mei C. The precision and agreement of corneal thickness and keratometry measurements with SS-OCT versus Scheimpflug imaging. EYE AND VISION 2020; 7:32. [PMID: 32528997 PMCID: PMC7285531 DOI: 10.1186/s40662-020-00197-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/19/2020] [Indexed: 11/23/2022]
Abstract
Purpose To assess the repeatability and reproducibility of swept-source optical coherence tomography (SS-OCT) and Scheimpflug system and evaluate the agreement between the two systems in measuring multiple corneal regions in children. Methods Pachymetric and keratometric maps for both systems were evaluated. Central, midperipheral and peripheral corneal thickness (CT), keratometry and astigmatism power vectors were recorded. The three outcomes yielded by the same observer were used to assess intraobserver repeatability. The differences in the mean values provided by each observer were used to evaluate interobserver reproducibility. Within-subject standard deviation, test-retest repeatability (TRT) and coefficient of variation (CoV) were used to analyze the intraobserver repeatability and interobserver reproducibility. Paired T-test and Bland-Altman were used to appraise interdevice agreement. Results Seventy-eight eyes of 78 children were included. The CoV was ≤2.12 and 1.10%, respectively, for repeatability and reproducibility. TRT and CoV were lower for central and paracentral CT measurements than for peripheral measurements. The SS-OCT device generated higher precision when acquiring CT data, whereas Scheimpflug system showed higher reliability when measuring corneal keratometry. Although the CT readings measured using SS-OCT were significantly thinner than Scheimpflug device (P < 0.001), the central and thinnest CT values were still of high agreement. The interdevice agreement of keratometry measurement was high for the central corneal region and moderate for the paracentral and peripheral areas. Conclusions The precision of CT measurements by SS-OCT was higher, while the reliability of keratometry measurements by the Scheimpflug system was higher in children. Apart from the measured values in the central corneal region, the thickness and keratometry readings should not be considered interchangeable between the two systems.
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Affiliation(s)
- Yune Zhao
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China.,Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang China
| | - Ding Chen
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China
| | | | - Qing Wang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Hongfang Zhang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China.,Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang China
| | - Yili Jin
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Benhao Song
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Rui Ning
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Jinhai Huang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China.,Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang China.,Eye Hospital of Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, 325027 Zhejiang China
| | - Chenyang Mei
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang China.,Key Laboratory of Vision Science, Ministry of Health P.R. China, Wenzhou, Zhejiang China.,Eye Hospital of Wenzhou Medical University, 270 West Xueyuan Road, Wenzhou, 325027 Zhejiang China
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[Reliability of corneal tomography after implantation of intracorneal ring segments for keratoconus]. Ophthalmologe 2020; 117:1092-1099. [PMID: 32140771 PMCID: PMC7644543 DOI: 10.1007/s00347-020-01074-w] [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] [Indexed: 11/01/2022]
Abstract
BACKGROUND AND OBJECTIVE Intracorneal ring segments (ICRS) are believed to stop the progression of keratoconus (KC). This statement on progression, however, requires knowledge about measurement reproducibility. The purpose of this study was to compare the reproducibility of tomographic parameters in eyes with KC after femtosecond laser-assisted implantation of INTACS (fs-INTACS) using two different devices and to determine which is more reliable for the follow-up of these patients. PATIENTS AND METHODS In this study 19 KC eyes were included and repeatedly examined 5 times with the Scheimpflug topography Pentacam HR and the Casia 2 optical coherence tomography (VA-OCT) devices. Outcome measures included the reproducibility and comparability of measurements between the two devices of (1) keratometric refractive power of the anterior cornea and (2) posterior cornea, (3) maximum keratometric refractive power, (4) central corneal thickness and (5) corneal thickness at the thinnest site. RESULTS The mean differences (Pentacam minus Casia 2) of (1), (2), (3), (4) and (5) were 0.67 dpt, 0.41 dpt, 3.4 dpt, 1.5 µm and 11.8 µm, respectively. The mean SDs of the 5 repeat measurements for (1), (2), (3), (4) and (5) were 0.20 dpt/0.20 dpt, 0.10 dpt/0.07 dpt, 0.75 dpt/0.5 dpt, 6.5 µm/2.4 µm (p = 0.007) and 7.3 µm/1.9 µm (p = 0.001) for Pentacam and Casia 2, respectively. Cronbach's alpha was better than 0.98 for both devices and all parameters. CONCLUSION Both Casia 2 and Pentacam enable a reliable assessment of the corneal refractive power in KC after fs-INTACS implantation; however, the reproducibility was significantly better with Casia 2 only for the measurement of corneal thickness. The Pentacam showed significantly higher values for the mean anterior and posterior corneal refractive power and measured significantly thicker at the thinnest point of the cornea compared to Casia 2.
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Fujimoto K, Inomata T, Okumura Y, Iwata N, Fujio K, Eguchi A, Nagino K, Shokirova H, Karasawa M, Murakami A. Comparison of corneal thickness in patients with dry eye disease using the Pentacam rotating Scheimpflug camera and anterior segment optical coherence tomography. PLoS One 2020; 15:e0228567. [PMID: 32012201 PMCID: PMC6996840 DOI: 10.1371/journal.pone.0228567] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/19/2020] [Indexed: 11/18/2022] Open
Abstract
The purpose of this study was to compare central corneal thickness, thinnest corneal thickness, and the thinnest point of the cornea between Pentacam and anterior segment optical coherence tomography (ASOCT) in patients with dry eye disease (DED). This cross-sectional study included 195 participants between November 2015-June 2017. DED was diagnosed using the Asia Dry Eye Society criteria and further divided into mild and severe DED based on kerato-conjunctival vital staining. Central corneal thickness, thinnest corneal thickness, and the thinnest point of the cornea measured by Pentacam and ASOCT were compared, and Pearson's correlation coefficients were estimated. The differences in central corneal thickness and the thinnest corneal thickness between Pentacam and ASOCT were analysed using Bland-Altman and multivariate regression analyses adjusted for age and sex. This study included 70 non-DED subjects and 52 patients with mild and 73 with severe DED. The Pentacam and ASOCT measurements of central corneal thickness and thinnest corneal thickness were strongly correlated, but the respective values were higher when measured with Pentacam. The Bland-Altman analysis revealed differences in central corneal thickness (non DED, 11.8; mild DED, 13.2; severe DED, 19.6) and in thinnest corneal thickness (non DED, 13.1; mild DED, 13.4; severe DED, 20.7). After adjusting for age and sex, the differences in central corneal thickness (β = 7.029 μm, 95%CI 2.528-11.530) and thinnest corneal thickness (β = 6.958 μm, 95%CI 0.037-13.879) were significantly increased in the severe-DED group. The distribution of the thinnest point of the cornea in the cornea's inferior temporal quadrant between Pentacam and ASOCT deviated in severe DED (Pentacam: 90.4% vs. ASOCT: 83.6%). Clinicians should consider that there were significant differences in corneal-morphology assessment between the measurements with Pentacam and ASOCT in severe DED.
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Affiliation(s)
- Keiichi Fujimoto
- Juntendo University Graduate School of Medicine, Department of Ophthalmology, Tokyo, Japan
| | - Takenori Inomata
- Juntendo University Faculty of Medicine, Department of Ophthalmology, Tokyo, Japan
- Juntendo University Faculty of Medicine, Department of Strategic Operating Room Management and Improvement, Tokyo, Japan
- Juntendo University Graduate School of Medicine, Department of Hospital Administration, Tokyo, Japan
- * E-mail:
| | - Yuichi Okumura
- Juntendo University Graduate School of Medicine, Department of Ophthalmology, Tokyo, Japan
- Juntendo University Faculty of Medicine, Department of Strategic Operating Room Management and Improvement, Tokyo, Japan
| | - Nanami Iwata
- Juntendo University Graduate School of Medicine, Department of Ophthalmology, Tokyo, Japan
| | - Kenta Fujio
- Juntendo University Graduate School of Medicine, Department of Ophthalmology, Tokyo, Japan
| | - Atsuko Eguchi
- Juntendo University Graduate School of Medicine, Department of Hospital Administration, Tokyo, Japan
| | - Ken Nagino
- Juntendo University Graduate School of Medicine, Department of Hospital Administration, Tokyo, Japan
| | - Hurramhon Shokirova
- Juntendo University Graduate School of Medicine, Department of Ophthalmology, Tokyo, Japan
| | - Maria Karasawa
- Juntendo University Graduate School of Medicine, Department of Ophthalmology, Tokyo, Japan
| | - Akira Murakami
- Juntendo University Graduate School of Medicine, Department of Ophthalmology, Tokyo, Japan
- Juntendo University Faculty of Medicine, Department of Ophthalmology, Tokyo, Japan
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Corneal Biomechanics in Unilateral Keratoconus and Fellow Eyes with a Scheimpflug-based Tonometer. Optom Vis Sci 2019; 95:608-615. [PMID: 29957740 DOI: 10.1097/opx.0000000000001241] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE Before the appearance of evident keratoconus, corneal biomechanical changes may be detectable. Here, these properties are analyzed to detect any difference that could help in the early recognition of keratoconus to allow patients to benefit from early treatments and to avoid refractive procedures in these corneas. PURPOSE The purpose of this study was to compare corneal biomechanical characteristics as determined by Corvis Scheimpflug Technology tonometry between normal eyes and asymmetric keratoconic eyes. METHODS Retrospective data from normal eyes (n = 100), keratoconic eyes (n = 18), and their topographically normal fellow eyes (n = 18) were analyzed. Differences in the variables among the groups were determined. For the parameters that showed significant differences, the receiver operating characteristic curve and the area under the curve (AUC) were used to assess the diagnostic accuracy of each variable. The optimal cutoff points were determined when comparing normal and fellow eyes. Also, a new linear combination of variables was performed to obtain better discriminative values. RESULTS The following variables differed significantly between normal and fellow eyes: length of the flattened cornea in the second applanation, peak distance, curvature radius at highest concavity, and central corneal thickness. When each variable was independently considered, AUCs, sensitivity, and specificity were insufficiently high for good discrimination between the two groups. However, using a linear combination of variables, an optimal cutoff point (0.157) was obtained with an AUC of 0.78, sensitivity of 0.84, and specificity of 0.69. CONCLUSIONS A best predictive linear combination of corneal biomechanical variables was tested including diameter of the flattened cornea in the second applanation and central corneal thickness. This combination was considered as the best in terms of its prediction capacity, simplicity and clinical application. This formula may be useful in clinical practice to discriminate between normal eyes and incipient keratoconus.
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Intraobserver Repeatability of Corneal and Anterior Segment Parameters Obtained Using a Scheimpflug Camera-Placido Corneal Topography System. BEYOGLU EYE JOURNAL 2019; 4:82-85. [PMID: 35187438 PMCID: PMC8842055 DOI: 10.14744/bej.2019.74946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 04/05/2019] [Indexed: 12/03/2022]
Abstract
Objectives: The aim of this study was to assess the intraobserver repeatability of central corneal thickness, peripheral corneal thickness (PCT), keratometry values (steep K, flat K), white-to-white diameter, and anterior chamber depth using the Sirius topography device (Costruzione Strumenti Oftalmici, Florence, Italy) in healthy eyes. Methods: A Sirius device was used by a single examiner to assess 100 eyes in 50 healthy patients. Two consecutive scans were acquired for each eye. Repeatability was assessed using test–retest variability, the coefficient of variation (COV), and the intraclass correlation coefficient (ICC). Results: Fifty patients (100 eyes) met the inclusion criteria. There were 18 women (36%) and 32 men (64%), with an age range of 23 to 56 years. The mean age was 30.38±8.03 years. A COV of 0.4% or less and an ICC of more than 0.99 (showing excellent repeatability) were achieved for most parameters, with the exception of PCT (at 2.5-mm temporal, superior, inferior, and nasal thickness). Conclusion: The anterior segment parameters obtained using the Sirius Scheimpflug camera- Placido corneal topography system were highly repeatable.
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Wolfel AE, Pederson SL, Cleymaet AM, Hess AM, Freeman KS. Anterior segment parameters in normal dogs using the Pentacam ® HR Scheimpflug system. Vet Ophthalmol 2019; 22:683-694. [PMID: 30715790 DOI: 10.1111/vop.12642] [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: 08/31/2018] [Revised: 11/22/2018] [Accepted: 11/27/2018] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To describe and compare normative anterior segment parameters between canine age groups using the Pentacam® HR Scheimpflug camera (Pentacam). ANIMALS STUDIED Thirty-six sedated dogs (60 eyes) of varying ages and breeds were imaged with the Pentacam; only nondiseased anterior segments were included. PROCEDURES Dogs were divided into three age groups: Group 1 (1-5 years), Group 2 (6-10 years), and Group 3 (11-15 years). Values assessed included central corneal thickness (CCT), anterior and posterior corneal elevation (ACE/PCE), anterior and posterior corneal curvature metrics, corneal volume (CV), anterior and posterior corneal astigmatism (AA/PA), anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA). Tukey-adjusted pairwise comparisons were performed. RESULTS Overall CCT (mean ± SD) was 631.07 ± 59.91 µm. Central corneal thickness was 608.60 ± 48.63 µm for Group 1, 648.57 ± 51.06 µm for Group 2, and 635.37 ± 73.71 µm for Group 3. Anterior corneal elevation (ACE) measured 9.08 ± 0.58 mm, PCE measured 8.04 ± 0.50 mm, and CV was 58.13 ± 5.39 mm3 . Astigmatism values were 1.34 ± 0.94 D for AA and 0.46 ± 0.44 D for PA. Anterior chamber values were 3.76 ± 0.56 mm for ACD, 383.68 ± 66.24 mm3 for ACV, and 23.62 ± 29.33˚ for ACA. Significant differences were found between Groups 1 and 2 for CV (55.08 ± 4.08 mm3 and 60.32 ± 4.19 mm3 , respectively), (P = 0.02). CONCLUSIONS Corneal volume significantly increased between Group 1 and Group 2. Central corneal thickness increased from Group 1 to Group 3, but was not significant with the current sample size. There were no other differences between age groups.
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Affiliation(s)
- Allison E Wolfel
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Samantha L Pederson
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Allison M Cleymaet
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
| | - Ann M Hess
- Department of Statistics, College of Natural Sciences, Colorado State University, Fort Collins, Colorado
| | - Kate S Freeman
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
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Kim H, An Y, Joo CK. Gender-differences in age-related changes of corneal astigmatism in Korean cataract patients. BMC Ophthalmol 2019; 19:31. [PMID: 30678644 PMCID: PMC6346567 DOI: 10.1186/s12886-018-1001-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 12/06/2018] [Indexed: 11/23/2022] Open
Abstract
Background This cross-sectional study investigated age-related changes in anterior, posterior, and total corneal astigmatism and evaluated sex differences in corneal astigmatism with increasing age in cataract patients. Methods This study evaluated eyes with cataracts from May 2009 and July 2013. All eyes underwent a complete ophthalmological examination and corneal Scheimpflug imaging by a Pentacam camera (Oculus, Wetzlar, Germany). Anterior, posterior, and total corneal astigmatism were determined. Power vector J0 and linear regression analyses were determined and compared with respect to age and sex. Results Four hundred and fifteen patients (217 men, 198 women) aged 20–89 years were evaluated. For anterior corneal astigmatism, 100% of patients who were 20–39 years old had with-the-rule (WTR) in both sexes. WTR was significantly lower in patients 80–89 years old (25.6% of men and 37.8% of women). For total corneal astigmatism, WTR also tended to decrease with increasing age: 93.3% of men and 100% of women 20–39 years old versus 20.9% of men and 31.1% of women 80–89 years old. The regression coefficient of both the anterior corneal and total corneal J0 vector values analyzed by age were − 0.018 in men and − 0.016 in women (both p < .001). Conclusions The against-the-rule shift was faster for total corneal astigmatism than for anterior corneal astigmatism and it occurred earlier in men than in women. Trial registration Retrospectively registered. Registration number: KC15RISI0241. Registered April 20, 2016.
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Affiliation(s)
- Hyojin Kim
- Department of Visual Optics, Division of Health Science and Graduate School of Health and Welfare, Baekseok University, Cheonan, South Korea
| | - Youngju An
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Choun-Ki Joo
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, South Korea. .,Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, #505 Banpo-Dong, Seocho-Gu, Seoul, 137-040, South Korea.
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Intrasubject Repeatability and Interdevice Agreement of Anterior Chamber Depth Measurements by Orbscan and Pentacam in Different Grades of Keratoconus. Eye Contact Lens 2019; 45:51-54. [PMID: 29944509 DOI: 10.1097/icl.0000000000000515] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To evaluate the repeatability of anterior chamber depth (ACD) measurements by Orbscan and Pentacam imaging devices in different grades of keratoconus. METHODS One examiner performed 3 consecutive ACD measurements with both devices on 74 eyes of 42 keratoconus patient. Repeatability was assessed using intrasession test-retest variability. Within-subject SD was determined for repeatability, and the coefficient of variation was calculated for each measurement. The intraclass correlation coefficient (ICC) was also determined to assess the variance of repeated data. RESULTS Overall, the three ACD measurements were not significantly different either with Pentacam or Orbscan. The ICC index values were greater than 90% with both devices, and it significantly reduced at higher grades of keratoconus with Pentacam. Interdevice differences were statistically significant. The interdevice agreement with ACD measurements was 0.981, and the agreement was lower at higher grades of keratoconus. The 95% limits of agreement between the 2 devices for ACD was from -0.19 to 0.04. CONCLUSIONS Our results indicate acceptable repeatability for ACD measurements with both Orbscan and Pentacam in keratoconus patients. The progression of keratoconus has no significant effect on repeatability results of these devices. The good agreement between them allows their interchangeable use.
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Repeatability of Anterior Curvature Metrics in Healthy and Keratoconic Eyes with a Portable Handheld Topographer. Optom Vis Sci 2018; 95:1142-1148. [PMID: 30451801 DOI: 10.1097/opx.0000000000001307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
SIGNIFICANCE This is a prospective observational investigation that studies the repeatability of several outcomes obtained with the Keratron Scout in healthy and keratoconic corneas. In addition, we have been able to determine the "noise" values of the instrument, which can be very useful when evaluating possible progression in keratoconus (KCN). PURPOSE The purpose of this study was to evaluate the repeatability of several anterior curvature metrics provided by a portable and handheld Placido disk-based topographer in healthy and keratoconic eyes. METHODS One eye from 50 keratoconic patients and 50 eyes from healthy patients were included in this prospective observational study. Two consecutive sessions (with three scans per session) were performed, and the following parameters were analyzed with a Keratron Scout topographer: flat keratometry, steep keratometry, flat corneal axis, corneal astigmatism, and flat and steep asphericities. In addition, in the KCN cohort, indices derived from the Cone Location and Magnitude Index were also recorded. Intrasession (first session, all three measurements) and intersession (one measurement from each session, selected randomly) statistics were calculated. The following variables were calculated: within-subject standard deviation, coefficient of repeatability (R), coefficient of variation, and intraclass correlation coefficient (ICC). RESULTS In healthy eyes, the intrasession and intersession ICCs were high (0.947 to 0.999), and for both flat keratometry and steep keratometry, the within-subject standard deviation was 0.08 and R was 0.24 diopters. Repeatability was slightly lower in the KCN group, but the ICC was greater than 0.95, whereas the R for flat keratometry was 0.41 diopters. CONCLUSIONS The Keratron Scout provides repeatable measures for the studied metrics in healthy and keratoconic eyes.
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Corneal Biomechanical Properties in Obstructive Sleep Apnea Syndrome. Eye Contact Lens 2018; 44 Suppl 2:S361-S364. [DOI: 10.1097/icl.0000000000000489] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Çavdarlı C, Topçu-Yılmaz P. Does Long-term Soft Contact Lens Wear Affect Corneal and Anterior Chamber Parameters? Turk J Ophthalmol 2018; 48:166-170. [PMID: 30202611 PMCID: PMC6126095 DOI: 10.4274/tjo.53486] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/04/2018] [Indexed: 12/01/2022] Open
Abstract
Objectives To assess the long-term effects of soft contact lenses (SCL) on the cornea and anterior chamber by topography. Materials and Methods Thirty-nine eyes of 22 healthy patients were included in this prospective study. Changes in corneal and anterior chamber parameters before and after 12 months of daily SCL use (Air Optix Aqua, Air Optix Aqua for Astigmatism, Acuvue Oasys and Acuvue Oasys for Astigmatism) were evaluated with Pentacam (Oculus, Germany). Results Best corrected visual acuity with toric SCL was significantly better compared to spectacles in the toric SCL group (0.98±0.34 vs 0.94±0.72, p=0.004). None of the corneal (horizontal and vertical keratometry, corneal volume, anterior and posterior corneal astigmatism, corneal pachymetry of apex and thinnest location) and anterior chamber (anterior chamber depth, volume and angle) parameters showed a statistically significant change after long-term daily wear of SCLs. Conclusion The results of this study revealed that long-term wear of current high oxygen permeable and relatively low modulus silicone hydrogel SCLs does not impact cornea and anterior chamber morphology or volumetric parameters. Furthermore, toric silicone hydrogel SCLs can provide better visual performance than spectacles.
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Affiliation(s)
- Cemal Çavdarlı
- University of Health Sciences, Ankara Numune Training and Research Hospital, Ophthalmology Clinic, Ankara, Turkey
| | - Pınar Topçu-Yılmaz
- University of Health Sciences, Ankara Numune Training and Research Hospital, Ophthalmology Clinic, Ankara, Turkey
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Habib A, Khan MS, Ishaq M, Yaqub MA. Agreement between Keratometric readings by VERION image guided System, Galilei G4 and Pentacam. Pak J Med Sci 2018; 34:740-743. [PMID: 30034450 PMCID: PMC6041539 DOI: 10.12669/pjms.343.14577] [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] [Indexed: 11/28/2022] Open
Abstract
Objective: To study Agreement between Keratometric readings by VERION image guided System, Galilei G4 and Pentacam. Methods: The quasi experimental study was conducted at Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan from August 2016 to December 2016. Twenty five patients fulfilling the inclusion criteria participated in the study. All Patients were subjected to Keratometric assessment using Galilei G4 Dual Scheimpflug analyzer (Ziemer, Switzerland), Wavelight Oculyzer II (Pentacam, Germany) and Verion image guided system (Alcon). Steep and flat meridian and diopter of astigmatism by three systems were recorded and endorsed. All readings were taken by the same observer. Statistical Program for Social Sciences (SPSS) version 22.0 was used for statistical analysis. Results analyzed for significance by t-tests and Interclass correlation analysis. In t tests, P values of <0.05 was considered statistically significant while interclass coefficient of >0.7 was considered acceptable. Results: Fifty eyes of twenty-five patients (22 male, 28 female) with mean age of 29.50 ± 3.46 years were studied. Flat K, steep K and dioptric power of astigmatism were measured with verion, pentacam and Galilei G4. Interclass correlation analysis showed agreement between individual variables measured by the three devices, while one sample t test showed no significant difference between dioptric power of astigmatism between Verion-Pentacam and Verion- Galilei group. (p 0.178 for former and 0.622 for later group). Conclusion: Verion image guided system is comparable to other instruments used currently for keratometry. Verion can be interchangeably used with Pentacam and Galilee G4 in assessing corneal astigmatism.
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Affiliation(s)
- Asad Habib
- Dr. Asad Habib, MBBS. Department of Ophthalmology, Armed forces institute of Ophthalmology (AFIO), Rawalpindi, Pakistan
| | - Muhammad Saim Khan
- Dr. Muhammad Saim Khan, FCPS, FICO, MRCSEd. Department of Ophthalmology, Armed forces institute of Ophthalmology (AFIO), Rawalpindi, Pakistan
| | - Mazhar Ishaq
- Dr. Mazhar Ishaq, FCPS/FRCSEd/FRCOphth. Department of Ophthalmology, Armed forces institute of Ophthalmology (AFIO), Rawalpindi, Pakistan
| | - Muhammad Amer Yaqub
- Dr. Muhammad Amer Yaqub, MCPS, FCPS, FRCS.Ed. Department of Ophthalmology, Armed forces institute of Ophthalmology (AFIO), Rawalpindi, Pakistan
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Elbedewy HA, Wasfy TE, Soliman SS, Sabry MM, Awara AM, El Emam SY, Shafik HM, Alam MR. Prevalence and topographical characteristics of keratoconus in patients with refractive errors in the Egyptian delta. Int Ophthalmol 2018; 39:1459-1465. [DOI: 10.1007/s10792-018-0965-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 06/16/2018] [Indexed: 11/29/2022]
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Repeated Same-Day Versus Single Tomography Measurements of Keratoconic Eyes for Analysis of Disease Progression. Cornea 2018; 37:474-479. [PMID: 29319597 PMCID: PMC5844585 DOI: 10.1097/ico.0000000000001513] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Purpose: Corneal tomography is used to assess progression of keratoconus and to direct clinical decisions regarding corneal cross-linking. The purpose of this study was to analyze the variability of repeated Scheimpflug-tomography (Pentacam Classic; Oculus, Wetzlar, Germany) measurements of keratoconic eyes in a clinical setting and to assess the validity of such measurements as a clinical decision-making tool. Methods: Eighty keratoconic eyes of 45 patients (age range 16–32 years) were examined at baseline and after follow-up periods of 3 to 6 months using 3 consecutive tomography measurements at each visit. Minimum corneal thickness and anterior sagittal curvature map parameters were studied [simulated keratometry (K) astigmatism (SimKast); maximum simulated K-reading (SimKmax); average SimK (SimKave); maximum K-readings on the 3-mm (Kmax3) and 5-mm (Kmax5) rings; and maximum K-reading (Kmax)]. Results: When comparing the first measurements at the first and second visits, respectively, 9% to 20% of eyes were classified as progressive depending on which parameter was chosen. Using the average of 3 consecutive measurements at each visit, 5% to 19% of eyes were classified as progressive. An increase in the SD of 3 consecutive measurements of SimKast (SD_SimKast) at the first visit of 1 diopter makes true progression of keratoconus 3.6 times more likely (odds ratio = 3.6; 95% confidence interval: 0.846–16.027; area under the curve = 0.70). Conclusions: The approach used to analyze progression in keratoconus, that is, single versus repeated measurements, may confer a great impact on the decision to perform corneal cross-linking treatment or not.
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Bao F, Savini G, Shu B, Zhu S, Gao R, Dang G, Yu A, Wang Q, Huang J. Repeatability, Reproducibility, and Agreement of Two Scheimpflug-Placido Anterior Corneal Analyzers for Posterior Corneal Surface Measurement. J Refract Surg 2017; 33:524-530. [DOI: 10.3928/1081597x-20170606-01] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 05/16/2017] [Indexed: 11/20/2022]
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Telek HH, Doluoglu OG, Burcu A, Demirok G, Ornek F, Ayyildiz A. The effects of tolterodine on anterior segment and choroidal thickness in patients with overactive bladder syndrome. Ther Adv Urol 2017; 9:91-97. [PMID: 28588646 DOI: 10.1177/1756287217701861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/07/2017] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND To evaluate the effects of tolterodine on anterior segment and choroidal thickness by using the Pentacam system and optical coherence tomography (OCT) (Pentacam). METHODS A total of 122 eyes of 61 patients (34 female; 27 male) were included in the study. All patients underwent a regular ocular examination and intraocular pressure measurements before and after 3 months of antimuscarinic drug tolterodine treatment, in addition, pupil diameter, anterior chamber depth, anterior chamber volume, anterior chamber angle, and lens thickness were measured through Pentacam (Oculus Inc., Wetzlar, Germany) system. Measurements of choroidal thickness were performed by OCT (Spectralis®, Heidelberg Engineering, Heidelberg, Germany). RESULTS The mean age was 58.4 ± 7.3 years and 56.5 ± 11.1 years for female and male patients. The mean intraocular pressure was 15.10 ± 2.75 mmHg before treatment and 15.18 ± 2.65 mmHg after treatment. Pupil diameters were 3.09 ± 0.48 mm before treatment and 3.12 ± 0.43 mm after treatment. Anterior chamber depth, before and after treatment were 2.68 ± 0.65 mm and 2.70 ± 0.61 mm. The mean value for subfoveal choroidal thickness was 267.92 ± 81.35 μm before the administration of tolterodine, whereas the mean choroidal thickness was 271.83 ± 75.42 μm after the administration of tolterodine. The alterations in the subfoveal choroidal thickness were not statistically significant (p = 0.862). CONCLUSIONS After 3 months of therapy with tolterodine, there were no significant changes in anterior segment parameters and choroidal thickness.
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Affiliation(s)
- Hande Hüsniye Telek
- Department of Ophthalmology Clinic, Ankara Training and Research Hospital, Ankara, Turkey
| | - Omer Gokhan Doluoglu
- Department of Urology Clinic of Ankara Training and Research Hospital, Sukriye Mahallesi, Ulucanlar Caddesi, No:89, 06340, Ankara, Turkey
| | - Ayse Burcu
- Department of Ophthalmology Clinic, Ankara Training and Research Hospital, Ankara, Turkey
| | - Gulizar Demirok
- Department of Ophthalmology Clinic, Ankara Training and Research Hospital, Ankara, Turkey
| | - Firdevs Ornek
- Department of Ophthalmology Clinic, Ankara Training and Research Hospital, Ankara, Turkey
| | - Ali Ayyildiz
- Department of Urology Clinic, Ankara Training and Research Hospital, Ankara, Turkey
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de Sanctis U, Donna P, Penna RR, Calastri MI, Eandi CM. Corneal Astigmatism Measurement by Ray Tracing Versus Anterior Surface-Based Keratometry in Candidates for Toric Intraocular Lens Implantation. Am J Ophthalmol 2017; 177:1-8. [PMID: 28185842 DOI: 10.1016/j.ajo.2017.01.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 01/26/2017] [Accepted: 01/28/2017] [Indexed: 10/20/2022]
Abstract
PURPOSE To compare corneal astigmatism derived from total corneal refractive power (CATCRP), a ray-tracing method, with that derived from simulated keratometry (CASimK), an anterior surface-based method, in candidates for toric intraocular lens (IOL) implantation. DESIGN Reliability analysis. METHODS In 1 eye of 200 consecutive patients (mean age 71 ± 9 years) with cataract, a Pentacam HR (Oculus) was used to measure CATCRP and CASimK. Eyes with CATCRP >1 diopter (D) were defined as candidates for toric IOL implantation. The estimation difference between CATCRP and CASimK was analyzed by calculating the arithmetic, absolute, and vector differences between the 2 methods. RESULTS Seventy-seven candidates were identified. In the candidates, CASimK was <1 D in 22% of cases and underestimated the astigmatism magnitude, on average, by -0.15 ± 0.34 D. The mean absolute and vector difference between CATCRP and CASimK was 0.31 ± 0.29 D and 0.30 ± 0.29 D × 180 degrees, respectively. The absolute and vector differences between the 2 methods were >0.50 D in 21 of 77 (27.2%) and 25 of 77 (32.5%) eyes, respectively; the proportions were significantly (P < .001) higher than in the eyes with CATCRP ≤1 D (0.8% and 9.8%, respectively). The difference in steep meridian alignment between CATCRP and CASimK was >5 degrees in 22.1% and >10 degrees in 2.6% of cases. CONCLUSION The difference between CATCRP and CASimK, as calculated by Pentacam HR, is greater in candidates for toric IOL implantation than in the general population. That difference considerably influences the candidate and toric IOL power selection in a large proportion of cases.
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Effects of single-segment Intacs implantation on visual acuity and corneal topographic indices of keratoconus. J Curr Ophthalmol 2017; 29:189-193. [PMID: 28913509 PMCID: PMC5587223 DOI: 10.1016/j.joco.2016.10.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 10/27/2016] [Accepted: 10/30/2016] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To assess the changes in visual acuity and topographic indices after implantation of single-segment Intacs. METHODS Forty-two keratoconic eyes received Femtosecond-assisted single-segment Intacs. Uncorrected distance visual acuity (UDVA) and best spectacle corrected visual acuity (BSCVA), refractive error, keratometry (K1, K2, Km, and KMax.), and seven Pentacam measured topographical indices; index of surface variance (ISV), index of vertical asymmetry (IVA), keratoconus index (KI), central keratoconus index (CKI), index of height asymmetry (IHA), index of height decentration (IHD), and minimum radius of curvature (R Min) were assessed 4 months after surgery. Correlations between changes of visual acuity and topographical indices changes were evaluated. RESULTS UDVA increased from 0.92 ± 0.35 to 0.49 ± 0.31 logMAR (P < 0.001), and BSCVA increased from 0.39 ± 0.15 to 0.23 ± 0.11 logMAR (P < 0.001). Subjective refraction spherical equivalent (SRSE) decreased from -3.92 ± 1.66 diopters (D) to -2.00 ± 1.51 D (P < 0.001). Mean central Keratometry decreased 2.16 ± 1.09 D from the preoperative readings (P < 0.001). All Pentacam topographical indices except CKI significantly improved (for IHA P = 0.046, for five others P < 0.001). The correlation between improvement in topographical indices and visual acuity improvements was not week. CONCLUSION Intacs implantation in keratoconic eyes increased visual acuity and made corneal shape less irregular. However, the improvements of visual acuity and corneal shape were not strongly correlated.
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Biomechanical Measurement of Rabbit Cornea by a Modified Scheimpflug Device. J Ophthalmol 2016; 2016:8271762. [PMID: 27446608 PMCID: PMC4947499 DOI: 10.1155/2016/8271762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 05/15/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose. To explore the probability and variation in biomechanical measurements of rabbit cornea by a modified Scheimpflug device. Methods. A modified Scheimpflug device was developed by imaging anterior segment of the model imitating the intact eye at various posterior pressures. The eight isolated rabbit corneas were mounted on the Barron artificial chamber and images of the anterior segment were taken at posterior pressures of 15, 30, 45, 60, and 75 mmHg by the device. The repeatability and reliability of the parameters including CCT, ACD, ACV, and CV were evaluated at each posterior pressure. All the variations of the parameters at the different posterior pressures were calculated. Results. All parameters showed good intraobserver reliability (Cronbach's alpha; intraclass correlation coefficient, α, ICC > 0.96) and repeatability in the modified Scheimpflug device. With the increase of posterior pressures, the ratio of CCT decreased linearly and the bulk modulus gradually reduced to a platform. The increase of ACD was almost linear with the posterior pressures elevated. Conclusions. The modified Scheimpflug device was a valuable tool to investigate the biomechanics of the cornea. The posterior pressure 15-75 mmHg range produced small viscoelastic deformations and nearly linear pressure-deformation response in the rabbit cornea.
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Kasprzak H, Boszczyk A. Numerical analysis of corneal curvature dynamics based on Corvis tonometer images. JOURNAL OF BIOPHOTONICS 2016; 9:436-444. [PMID: 26997615 DOI: 10.1002/jbio.201500235] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 02/11/2016] [Accepted: 03/01/2016] [Indexed: 06/05/2023]
Abstract
The paper presents numerical analysis of corneal curvature distribution, based on Corvis ST images. It was shown that a new approach to analysis of corneal curvature from tonometer images enables a better description and understanding of processes during fast corneal deformation. Ten healthy volunteers participated in nine repeated measurements on one eye. 90 sequences of images were processed with software written in Matlab, with the use of the Image Processing Toolbox. Time-spatial distribution of the local curvature distribution of the corneal profile was obtained for each and every measurement. Some new curvature parameters were proposed and analyzed. A high repeatability for individual subjects was obtained for the proposed parameters. For four of these new parameters, the ICC coefficients were higher than 0.85. The ICC value for the calculated curvature of the cornea before deformation reaches 0.989. Such high repeatability of the proposed new parameters can be useful in examination and differentiation of corneas due to their geometrical and biomechanical properties.
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Affiliation(s)
- Henryk Kasprzak
- Department of Optics and Photonics, Wroclaw University of Technology, 50 370, Wroclaw, Poland.
| | - Agnieszka Boszczyk
- Department of Optics and Photonics, Wroclaw University of Technology, 50 370, Wroclaw, Poland
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Hashemi H, Beiranvand A, Yekta A, Maleki A, Yazdani N, Khabazkhoob M. Pentacam top indices for diagnosing subclinical and definite keratoconus. J Curr Ophthalmol 2016; 28:21-6. [PMID: 27239598 PMCID: PMC4881219 DOI: 10.1016/j.joco.2016.01.009] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 01/26/2016] [Accepted: 01/26/2016] [Indexed: 11/17/2022] Open
Abstract
Purpose To determine pachymetric, aberrometric, and topometric indices in patients with definite and subclinical keratoconus and the validity of these indices in the diagnosis of keratoconus. Methods We evaluated 262 keratoconic and 97 healthy eyes in this study. Pentacam HR examination was performed for all participants, and the data of all pachymetric, aberrometric, and topometric indices was extracted for the study population. Results The average of all evaluated pachymetric and topometric indices and the 3rd and 5th order vertical coma aberrations showed a significant difference between the study groups (p < 0.001). Belin/Ambrosio Deviation Display (BAD_D), Index of Vertical Asymmetry (IVA), Index of Surface Variance (ISV), and 5th order vertical coma aberration were identified as the best diagnostic criteria for the diagnosis of subclinical keratoconus (R2 = 0.65, p <0.001), and BAD_D, mean keratometry and 3rd order vertical coma aberration were identified as the best diagnostic criteria for the diagnosis of definite keratoconus (R2 = 0.91, p <0.001). The sensitivity and specificity of the above-mentioned models were 83.6% and 96.9%, and 97.9% and 96.9%, respectively. Conclusion Simultaneous evaluation of BAD_D, 5th order vertical coma aberration, IVA, and ISV, especially when the pattern of the corneal curvature is normal, can detect subclinical keratoconus with high sensitivity and specificity. As for definite keratoconus, each of the BAD_D, mean keratometry, and 3rd order vertical coma aberration indices has a desirable diagnostic validity. However, the aforementioned indices do not negate the importance of widely recognized and acceptable indices like keratometry and central corneal thickness.
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Affiliation(s)
- Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Asghar Beiranvand
- Health and nutrition Research Center, Lorestan University of Medical Sciences, Khoramabad, Iran
| | - Abbasali Yekta
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Azam Maleki
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Negareh Yazdani
- Department of Epidemiology, Faculty of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Khabazkhoob
- Department of Epidemiology, Faculty of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Chetty E. Precision of anterior and posterior corneal curvature measurements taken with the Oculus Pentacam. AFRICAN VISION AND EYE HEALTH 2016. [DOI: 10.4102/aveh.v75i1.329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
In the era of rapid advances in technology, new ophthalmic instruments are constantly influencing health sciences and necessitating investigations of the accuracy and precision of the new technology. The Oculus Pentacam (70700) has been available for some time now and numerous studies have investigated the precision of some of the parameters that the Pentacam is capable of measuring. Unfortunately some of these studies fall short in confusing the meaning of accuracy and precision and in not being able to analyse the data correctly or completely. The aim of this study was to investigate the precision of the anterior and posterior corneal curvature measurements taken with the Oculus Pentacam (70700) holistically with sound multivariate statistical methods. Twenty successive Pentacam measurements were taken over three different measuring sessions on one subject. Keratometric data for both the anterior and posterior corneal surfaces were analysed using multivariate statistics to determine the precision of the Oculus Pentacam. This instrument was found to have good precision both clinically and statistically for anterior corneal measurements but only good clinical precision for the posterior corneal surface. Key words: Oculus Pentacam; keratometric variation; corneal curvature; multivariate statistics
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Mashige KP. Repeatability and reproducibility of horizontal corneal diameter and anterior corneal power measurements using the Oculus Keratograph 4. AFRICAN VISION AND EYE HEALTH 2016. [DOI: 10.4102/aveh.v75i1.350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Purpose: To evaluate the repeatability and reproducibility of horizontal corneal diameter (HCD) and anterior corneal power (ACP) measurements obtained with the Oculus Keratograph 4 (OCULUS Optikgeräte GmbH).Methods: These parameters (HCD and ACP) were prospectively measured in quick succession three times in each of the right eyes of 40 healthy subjects, aged 18–28 years, with normal vision (6/6 or better visual acuity) in the first session by a single examiner. Measurements were then repeated in the second session scheduled 1 week later by the same examiner using the same instrument. Repeatability and reproducibility of HCD and ACP measurements was assessed based on the intra-session and intersession within-subject standard deviation (sw), repeatability (2.77sw), coefficient of variation (CoV) and intra-class correlation coefficient (ICC).Results: Intra-session repeatability and intersession reproducibility of all measured parameters showed a repeatability (2.77sw) of 0.35 mm or less for HCD and 0.35 D or less for ACP, a CoV of 0.30% or less and an ICC of more than 0.9.Conclusion: HCD and ACP measurements obtained using an Oculus Keratograph 4 show good repeatability and reproducibility in healthy eyes; therefore, these parameters can be used for longitudinal follow-up when measured with this device.
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Flynn TH, Sharma DP, Bunce C, Wilkins MR. Differential precision of corneal Pentacam HR measurements in early and advanced keratoconus. Br J Ophthalmol 2015; 100:1183-7. [DOI: 10.1136/bjophthalmol-2015-307201] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 11/08/2015] [Indexed: 11/04/2022]
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Evaluation of Central Corneal Thickness Using Corneal Dynamic Scheimpflug Analyzer Corvis ST and Comparison with Pentacam Rotating Scheimpflug System and Ultrasound Pachymetry in Normal Eyes. J Ophthalmol 2015; 2015:767012. [PMID: 26697213 PMCID: PMC4678087 DOI: 10.1155/2015/767012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 11/16/2015] [Indexed: 11/25/2022] Open
Abstract
Purpose. To assess the repeatability and reproducibility of central corneal thickness (CCT) measurements by corneal dynamic Scheimpflug analyzer Corvis ST in normal eyes and compare the agreement with Pentacam rotating Scheimpflug System and ultrasound pachymetry. Methods. 84 right eyes underwent Corvis ST measurements performed by two operators. The test-retest repeatability (TRT), within-subject coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were used to evaluate the intraoperator repeatability and interoperator reproducibility. CCT measurements also were obtained from Pentacam and ultrasound pachymetry by the first operator. The agreement between the three devices was evaluated with 95% limits of agreement (LoA) and Bland-Altman plots. Results. Corvis ST showed high repeatability as indicated by TRT ≤ 13.0 μm, CoV < 0.9%, and ICC > 0.97. The interoperator reproducibility was also excellent. The CoV was <0.9%, and ICC was >0.97. Corvis ST showed significantly lower values than Pentacam and ultrasound pachymetry (P < 0.001). The 95% LoA between Corvis ST and Pentacam or ultrasound pachymetry were −15.8 to 9.5 μm and −27.9 to 12.3 μm, respectively. Conclusions. Corvis ST showed excellent repeatability and interoperator reproducibility of CCT measurements in normal eyes. Corvis ST is interchangeable with Pentacam but not with ultrasound pachymetry.
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Tian M, Miao H, Shen Y, Gao J, Mo X, Zhou X. Intra- and Intersession Repeatability of an Optical Quality and Intraocular Scattering Measurement System in Children. PLoS One 2015; 10:e0142189. [PMID: 26536120 PMCID: PMC4633240 DOI: 10.1371/journal.pone.0142189] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 10/19/2015] [Indexed: 11/18/2022] Open
Abstract
Purpose To evaluate intra- and intersession repeatability of objective optical quality and intraocular scattering measurements with a double-pass system in children. Methods Forty-two eyes of 42 children were included in the study. An optical quality analysis system (OQAS) was used to measure optical quality parameters, including modulation transfer function cutoff frequency (MTFcutoff), Strehl ratio (SR), OQAS values (OV) at 3 different contrasts and objective scatter index (OSI). Three measurement sessions with 10-min intervals were operated by the same technician, and in each session four consecutive measurements were obtained. Results Mean values for MTFcutoff, SR and OSI were 46.85 ± 7.45cpd, 0.27 ± 0.06 and 0.34 ± 0.22 respectively. 1) The intraclass correlation coefficients were ranged from 0.89 to 0.97 and coefficients of variation from 0.06 to 0.16 for all the parameters in the first session; the relative repeatability were 11.1% (MTFcutoff), 22.5% (SR), 10.9% (OV100%), 16.6% (OV2%), 22.4% (OV9%) and 56.3% (OSI). Similar results were found in the second and third sessions. 2) Bland-Altman analysis showed that narrow 95% confidence intervals (compared between the first and second sessions) ranged from -5.42 to 5.28 (MTFcutoff), -0.05 to 0.07 (SR), -0.18 to 0.18 (OV100%), -0.26 to 0.29 (OV20%), -0.33 to 0.39 (OV9%) and -0.11 to 0.09 (OSI); the comparison between any two of the three sessions showed similar results. Conclusion Measurements of optical quality and intraocular scattering in children by the double-pass system showed good intra- and intersession repeatability. Retinal image quality is high and intraocular scattering is low in children.
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Affiliation(s)
- Mi Tian
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, People's Republic of China
| | - Huamao Miao
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, People's Republic of China
| | - Yang Shen
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, People's Republic of China
| | - Jian Gao
- Center of Clinical Epidemiology and Evidence-based Medicine, Fudan University, Shanghai, People's Republic of China
| | - Xiaofen Mo
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, People's Republic of China
- * E-mail: (XZ); (XM)
| | - Xingtao Zhou
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, People's Republic of China
- * E-mail: (XZ); (XM)
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