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Choi JY, Kim H, Kim JK, Lee IS, Ryu IH, Kim JS, Yoo TK. Deep learning prediction of steep and flat corneal curvature using fundus photography in post-COVID telemedicine era. Med Biol Eng Comput 2024; 62:449-463. [PMID: 37889431 DOI: 10.1007/s11517-023-02952-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 10/14/2023] [Indexed: 10/28/2023]
Abstract
Recently, fundus photography (FP) is being increasingly used. Corneal curvature is an essential factor in refractive errors and is associated with several pathological corneal conditions. As FP-based examination systems have already been widely distributed, it would be helpful for telemedicine to extract information such as corneal curvature using FP. This study aims to develop a deep learning model based on FP for corneal curvature prediction by categorizing corneas into steep, regular, and flat groups. The EfficientNetB0 architecture with transfer learning was used to learn FP patterns to predict flat, regular, and steep corneas. In validation, the model achieved a multiclass accuracy of 0.727, a Matthews correlation coefficient of 0.519, and an unweighted Cohen's κ of 0.590. The areas under the receiver operating characteristic curves for binary prediction of flat and steep corneas were 0.863 and 0.848, respectively. The optic nerve and its peripheral areas were the main focus of the model. The developed algorithm shows that FP can potentially be used as an imaging modality to estimate corneal curvature in the post-COVID-19 era, whereby patients may benefit from the detection of abnormal corneal curvatures using FP in the telemedicine setting.
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Affiliation(s)
- Joon Yul Choi
- Department of Biomedical Engineering, Yonsei University, Wonju, South Korea
| | | | - Jin Kuk Kim
- Department of Refractive Surgery, B&VIIT Eye Center, B2 GT Tower, 1317-23 Seocho-Dong, Seocho-Gu, Seoul, South Korea
| | - In Sik Lee
- Department of Refractive Surgery, B&VIIT Eye Center, B2 GT Tower, 1317-23 Seocho-Dong, Seocho-Gu, Seoul, South Korea
| | - Ik Hee Ryu
- Department of Refractive Surgery, B&VIIT Eye Center, B2 GT Tower, 1317-23 Seocho-Dong, Seocho-Gu, Seoul, South Korea
- Research and Development Department, VISUWORKS, Seoul, South Korea
| | - Jung Soo Kim
- Research and Development Department, VISUWORKS, Seoul, South Korea
| | - Tae Keun Yoo
- Department of Refractive Surgery, B&VIIT Eye Center, B2 GT Tower, 1317-23 Seocho-Dong, Seocho-Gu, Seoul, South Korea.
- Research and Development Department, VISUWORKS, Seoul, South Korea.
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López-Muñoz A, López-Castaño I, Torres-Parejo Ú, García-Romera MC. A Corneal Biomechanical Study Measured with a Scheimpflug Dynamic Analyser in Soft Contact Lens Wearers. Life (Basel) 2023; 13:2313. [PMID: 38137914 PMCID: PMC10744429 DOI: 10.3390/life13122313] [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: 10/10/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
The aim of this study was to evaluate the biomechanical changes in the cornea after wearing soft contact lenses (CLs) in healthy myopic patients measured with a Corvis ST® (CST, Oculus Optikgeräte GmbH, Wetzlar, Germany) analyser. This prospective, cross-sectional, single-centre study was performed on twenty-two Caucasian patients aged between 19 and 24 years (20.64 ± 1.21 years) range. Five device-specific biomechanical parameters, the central corneal thickness (CCT), and biomechanically corrected intraocular pressure (bIOP) were measured prior to fitting and one month after CL wear. Differences between the means of the deflection amplitude ratio (DA Ratio) and the standard deviation of the DA Ratio (SD DA Ratio) pre- and post-CL wear were found to be significant (p value = 0.002 in both cases). Significant differences were found between pre- and post-CL wear values in CCT (p value = 0.013). For all other biomechanical measures, no significant differences were observed before and after treatment. A significant association was found between changes in bIOP and classification according to changes in Int. Radius (p value = 0.047) and SSI (p value = 0.026) standard deviations. The corneal biomechanical indices provided by CST demonstrate that the fitting of soft CLs is a safe optical compensation method for the stability of corneal stiffness. No significant differences were found pre- and post-CL wear in the assessment of bIOP.
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Affiliation(s)
- Alfredo López-Muñoz
- Department of Physics of Condensed Matter, Optics Area, Vision Sciences Research Group (CIVIUS), Pharmacy School, University of Seville, 41009 Seville, Spain; (I.L.-C.); (M.-C.G.-R.)
- Research & Development Department (Miranza Virgen de Luján®), Ophthalmology Center, 41011 Seville, Spain
| | - Isabel López-Castaño
- Department of Physics of Condensed Matter, Optics Area, Vision Sciences Research Group (CIVIUS), Pharmacy School, University of Seville, 41009 Seville, Spain; (I.L.-C.); (M.-C.G.-R.)
| | - Úrsula Torres-Parejo
- Department of Statistics and Operations Research, University of Grenade, 18071 Grenade, Spain;
| | - Marta-C. García-Romera
- Department of Physics of Condensed Matter, Optics Area, Vision Sciences Research Group (CIVIUS), Pharmacy School, University of Seville, 41009 Seville, Spain; (I.L.-C.); (M.-C.G.-R.)
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Avetisov SE, Musaeva GM, Bubnova IA. [Effect of conventional and orthokeratological hard contact lenses on anatomical and functional characteristics of the cornea]. Vestn Oftalmol 2023; 139:7-15. [PMID: 36924510 DOI: 10.17116/oftalma20231390117] [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: 03/18/2023]
Abstract
Contact lenses are widely used for correction of myopia due to their accessibility, effectiveness and relative safety. PURPOSE This study evaluated the potential effects of conventional hard contact lenses (HCL) and orthokeratological contact lenses (OKL) on anatomical and functional condition of the cornea in myopia correction. MATERIAL AND METHODS The study included 80 patients (159 eyes) with low, moderate and high myopia. Group 1 consisted of 40 patients (79 eyes) who used conventional HCL; group 2 included 40 patients (80 eyes) who used OKL. All patients underwent topographic keratometry, corneal pachymetry mapping (Pentacam, Oculus, Germany; Visante OCT, Carl Zeiss, Germany), high-order aberrometry (OPD Scan, Nidek, Japan), confocal microscopy (Confoscan 4, Nidek, Japan), evaluation of corneal biomechanical properties (ORA, Reichert Technologies, USA) and corneal light scattering (Pentacam, Oculus, Germany). Examinations were taken before the treatment started and after 8-12 months of contact lens wear. RESULTS Group 1 showed corneal thickness increase in all zones (by 0.9-1.1%), no significant changes in corneal refraction, and increase in corneal hysteresis and corneal resistance factor. OKL wear led to a significant flattening of anterior surface of the cornea and steepening of its paracentral area, decrease in central corneal thickness (by 2.8%) and increase in mid-peripheral thickness (by 2.2%). No significant changes in posterior corneal surface were observed in the study patients. More significant increase in higher-order aberrations and the degree of light scattering was observed in group 2, while changes in subepithelial nerve plexus and stromal structure were more significant in group 1. CONCLUSION Long-term OKL wear shows more significant morphological and functional corneal changes compared to RGP lens.
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Affiliation(s)
- S E Avetisov
- Krasnov Research Institute of Eye Disease, Moscow, Russia.,I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - G M Musaeva
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - I A Bubnova
- Krasnov Research Institute of Eye Disease, Moscow, Russia
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Peyman A, Ghoreishi M, Hashemi-Estabragh SS, Mirmohammadkhani M, Mohammadinia M, Pourazizi M. Corneal biomechanical properties after soft contact lens wear measured on a dynamic Scheimpflug analyzer: A before and after study. J Fr Ophtalmol 2021; 44:391-396. [PMID: 33618908 DOI: 10.1016/j.jfo.2020.06.050] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 06/02/2020] [Accepted: 06/08/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To evaluate the corneal biomechanics before and after daily use of contact lenses (CLs), measured by Scheimpflug-based devices. METHODS This prospective clinical study includes participants who were scheduled to use CLs daily for refractive error. The biomechanical parameters were measured by the Corneal Visualization Scheimpflug Technology (Corvis ST) before and one month after using the soft CLs. RESULTS Twenty-three subjects (46 eyes), including 16 female (76.2%) with a mean age of 28±7.29 years, were enrolled. There was no significant difference among biomechanical factors measured before and after contact lens wear (P>0.05). Using regression analysis of the biomechanical markers, we found a statistically significant association between second applanation length (A2 length) (P=0.001), highest concavity radius (HCR) (P=0.05), deflection amplitude ratio (DA_ratio) (P=0.05) and integrated radius (P<0.001) with age. Regarding spherical equivalent, we found a statistically significant association between central corneal thickness (CCT) (P=0.05), A2 length (P=0.03) and stiffness parameter at first applanation (SPA1) (P=0.02). CONCLUSIONS We did not find a significant difference in terms of corneal biomechanical parameters between baseline and month 1; but regression analyses showed a statistically significant association between A2 length, HCR, DA_ratio, integrated radius, CCT and SPA1 and certain subject characteristics.
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Affiliation(s)
- A Peyman
- Isfahan Eye Research Center, Department of Ophthalmology, Isfahan University of Medical Sciences, Feiz Hospital, Modares St., Isfahan, Iran.
| | - M Ghoreishi
- Parsian Vision Research Institute, Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - S-S Hashemi-Estabragh
- Isfahan Eye Research Center, Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran.
| | - M Mirmohammadkhani
- Social Determinants of Health Research Center, Semnan University of Medical Sciences, Semnan, Iran And Department of Epidemiology and Biostatistics, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
| | | | - M Pourazizi
- Isfahan Eye Research Center, Department of Ophthalmology, Isfahan University of Medical Sciences, Feiz Hospital, Modares St., Isfahan, Iran.
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Jin Y, McAlinden C, Sun Y, Wen D, Wang Y, Yu J, Feng K, Song B, Wang Q, Chen S, Huang J. Sirius Scheimpflug-Placido versus ultrasound pachymetry for central corneal thickness: meta-analysis. EYE AND VISION 2021; 8:5. [PMID: 33602345 PMCID: PMC7891160 DOI: 10.1186/s40662-021-00227-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 01/13/2021] [Indexed: 11/26/2022]
Abstract
Background To compare the difference in central corneal thickness (CCT) measurements in normal eyes between a rotating Scheimpflug camera combined with a Placido-disk corneal topographer (Sirius, CSO, Italy) and ultrasound pachymetry (USP). Methods A systematic literature search was conducted for relevant studies published on PubMed, Medline, EMBASE, and the Cochrane Library and ClinicalTrials.gov from inception to August 1st, 2019. Primary outcome measures were CCT measurements between Sirius and USP. A random effects model was used to pool CCT measurements. Results A total of twelve studies involving 862 eyes were included in this meta-analysis. The meta-analysis found CCT measurements between Sirius and USP to be statistically significantly different (P < 0.0001). The mean difference between Sirius and USP was −11.26 μm with a 95% confidence interval (CI) (−16.92 μm, −5.60 μm). The heterogeneity was I2 = 60% (P = 0.004). Conclusion CCT measurements with the Sirius Scheimpflug-Placido topographer were statistically significantly lower than USP. However, it may be argued that the mean difference of 11.26 μm is not a clinically significant difference.
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Affiliation(s)
- Yili Jin
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Colm McAlinden
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China.,Department of Ophthalmology, Singleton Hospital, Swansea Bay University Health Board, Swansea, UK
| | - Yong Sun
- Shenzhen Hospital of Integrated Traditional and Western Medicine, Shenzhen, China
| | - Daizong Wen
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yiran Wang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jinjin Yu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ke Feng
- 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
| | - Qinmei Wang
- 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
| | - Shihao Chen
- 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.
| | - 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.
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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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Alzahrani K, Cristian C, Harper S, Carley F, Brahma A, Morley D, Hillarby MC. Corneal imaging and densitometry measurements in keratoconus patients to monitor disease progression and treatment outcomes after contact lens or Intacs treatment. Clin Ophthalmol 2018; 12:1653-1658. [PMID: 30233127 PMCID: PMC6130308 DOI: 10.2147/opth.s168865] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aim The aim of this study was to compare the pre- and posttreatment corneal densitometry and corneal thickness value of keratoconus (KCN) patients managed via contact lenses (CLs) or by both intrastromal corneal rings and contact lenses. Patients and methods This prospective study was performed at the Manchester Royal Eye Hospital, UK. Patients were recruited before treatment and followed up for 12 months. Data of corneal densitometry and corneal thickness were collected using the Oculus Pentacam at the pretreatment visit and posttreatment visit at 12 months. Results Corneal clarity significantly differs between both groups at pre treatment at zone 0-2 mm for the anterior layer (P=0.002). The same diversity is present at zone 2-6 mm for the anterior layer (P=0.003) and posterior layer (P=0.008). The corneal clarity diversity found was not statistically significant at 12 months post treatment (P>0.05). Corneal thickness was found to be statistically significantly different between pre treatment and post treatment for the CL group for central corneal thickness (CCT) and thinnest area (P=0.01 and P=0.02), respectively. Discussion This study shows that KCN management with Intacs was found to be effective in maintaining corneal clarity for a longer time than that with CL alone. On the other hand, corneal clarity reduces with disease progression in cases managed with CLs only. Analysis of Oculus Pentacam images provides an objective evaluation to monitor the corneal status after these different pathways of management.
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Affiliation(s)
- Khaled Alzahrani
- Division of Pharmacy and Optometry, School of Health Sciences, University of Manchester, Manchester, UK, .,Ophthalmology Department, King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia,
| | | | | | | | - Arun Brahma
- Manchester Royal Eye Hospital, Manchester, UK
| | | | - M Chantal Hillarby
- Division of Pharmacy and Optometry, School of Health Sciences, University of Manchester, Manchester, UK,
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Lloyd-McKernan A, Simo Mannion L, O’Dwyer V. The effect of previous soft contact lens wear on corneal refractive surgery outcomes. Cont Lens Anterior Eye 2017; 40:301-310. [DOI: 10.1016/j.clae.2017.05.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 05/29/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022]
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Soeters N, Visser ES, Imhof SM, Tahzib NG. Scleral lens influence on corneal curvature and pachymetry in keratoconus patients. Cont Lens Anterior Eye 2015; 38:294-7. [DOI: 10.1016/j.clae.2015.03.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 02/12/2015] [Accepted: 03/06/2015] [Indexed: 11/29/2022]
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Ma F, Xu M, Qian Y, Gao G, Dai J. Impact of long-term soft contact lens wear on epithelial flap production and postoperative recovery in laser-assisted subepithelial keratomileusis. Acta Ophthalmol 2015; 93:e67-73. [PMID: 25043677 DOI: 10.1111/aos.12499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 06/17/2014] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate the impact and postoperative clinical recovery of long-term soft contact lens wear on the epithelial flap made during laser-assisted subepithelial keratomileusis (LASEK). METHODS In a prospective study, 371 patients (589 eyes) who underwent LASEK were divided into four groups (G1, G2, G3, G4) according to their length of soft contact lens wear. After the contact lens (CL) was removed 1 week after surgery, various symptoms - uncorrected visual acuity (UCVA), oedema of the corneal epithelium, spherical equivalent (SE) and haze degree - were recorded on day 1, and at 1 and 3 months postoperatively. RESULTS There were no significant differences in corneal flap production among the first three groups that wore CLs, but various symptoms and UCVA were all different from the fourth group that did not wear CLs. There were statistically significant differences in oedema of corneal epithelium among the first three groups, and the degree of oedema was positively correlated with the CL wearing time. There were no significant differences in postoperative SE and haze in all four groups. CONCLUSIONS Long-term soft CL wear can affect production of the epithelial flap and postoperative recovery, including various symptoms, oedema of the central corneal epithelium and visual acuity. In contrast, there was no effect of long-term CL wear on postoperative mean refractive spherical equivalent (MRSE) and haze.
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Affiliation(s)
- Fei Ma
- Department of Ophthalmology; Jinling Hospital; School of Medicine; Nanjing University; Nanjing China
| | - Man Xu
- Department of Ophthalmology; Xi'an No. 4 hospital; Xi'an China
| | - Yifeng Qian
- Department of Ophthalmology; the First Affiliated Hospital of Soochow University; Suzhou China
| | - Guohong Gao
- Department of Ophthalmology; Eye & ENT Hospital; Fudan University; Shanghai China
- Key Laboratory of Myopia; Ministry of Health PR China; Shanghai China
| | - Jinhui Dai
- Department of Ophthalmology; Eye & ENT Hospital; Fudan University; Shanghai China
- Key Laboratory of Myopia; Ministry of Health PR China; Shanghai China
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Anterior amorphous corneal opacity and corneal thinning. Taiwan J Ophthalmol 2014. [DOI: 10.1016/j.tjo.2014.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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The influence of soft contact lens wear and two weeks cessation of lens wear on corneal curvature. Cont Lens Anterior Eye 2013; 37:31-7. [PMID: 23973214 DOI: 10.1016/j.clae.2013.07.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 07/23/2013] [Accepted: 07/26/2013] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Accurate corneal measurements are crucial in corneal refractive surgery (CRS) to ensure successful outcomes. Soft contact lens (SCL) wear may result in changes to corneal curvature and structure. United States Food and Drug Administration (FDA) pre-operative guidelines recommend that prior to CRS, SCL wearers cease SCL wear for "at least two weeks before examination and treatment" [1]. Corneal curvature changes induced by SCL wear may take longer than two weeks to resolve. PURPOSE To examine the effect of SCL wear on corneal curvature before and following two weeks SCL wear cessation. To explore the possible impact of different SCL materials and years of SCL wear. METHODS Retrospective data analysis, between a group of SCL wearers (SCL: n=45); and a non-contact lens control group (NCL: n=45). Corneal curvature parameters were measured using the Pentacam (Oculus, Germany), before and following two weeks cessation of SCL wear. RESULTS No significant differences in keratometry or Sagittal radius of curvature between SCL and NCL groups prior to or following SCL cessation. Tangential radius of curvature showed significant inferior steepening for the SCL group prior to SCL cessation (SCL vs. NCL; 7.77±0.30mm vs. 7.90±0.30mm; p=0.04). Following two weeks cessation of SCL wear this appeared to have resolved. CONCLUSIONS Two weeks cessation of SCL wear appears sufficient for resolution of corneal curvature changes with modern SCL materials and years of SCL wear. However, further studies with longer lens deprivation periods are required to ensure stability for all SCL wearing patients.
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Corneal changes following short-term rigid contact lens wear. Cont Lens Anterior Eye 2012; 35:129-36. [DOI: 10.1016/j.clae.2012.01.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 01/01/2012] [Accepted: 01/19/2012] [Indexed: 11/23/2022]
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Behki R, Damji KF, Crichton A. Canadian perspectives in glaucoma management: The role of central corneal thickness. Can J Ophthalmol 2007. [DOI: 10.3129/can.j.ophthalmol.06-108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Iskeleli G, Onur U, Ustundag C, Ozkan S. Comparison of Corneal Thickness of Long-Term Contact Lens Wearers for Different Types of Contact Lenses. Eye Contact Lens 2006; 32:219-22. [PMID: 16974153 DOI: 10.1097/01.icl.0000240176.75911.9c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare the central corneal thickness (CCT) values of long-term wearers of different types of contact lenses with those of each other and a normal control group. METHODS Twenty-three healthy eyes with no history of contact lens wear were used for the control group. Forty-eight eyes were evaluated in four different groups according to the type of contact lens worn; each group comprised 12 eyes. Group 1 (SofLens 38) and group 2 (Contact Day 30) had worn daily-wear frequent-replacement soft contact lenses with a 38% and 55% water content, respectively, and they had worn their lenses for an average of 4.28 +/- 1.70 years and 3.71 +/- 1.11 years, respectively. Group 3 (Wöhlk A90) and group 4 (Conflex-air) had worn daily-wear rigid gas-permeable (RGP) contact lenses with a Dk/t value of 68 and 22, respectively, and they had worn their lenses for an average of 3.00 +/- 0.63 years and 3.25 +/- 1.17 years, respectively. CCT values in micrometers were measured by optical coherence tomography. RESULTS When comparing the CCT between the control group and the contact lens groups, the CCT was significantly thinner in the group wearing Conflex-air RGP contact lenses with a low Dk/t value (P = 0.010). In comparing the CCT among the four contact lens groups, the CCT was significantly thinner in the group wearing SofLens 38 contact lenses with a water content of 38% than in the group wearing Contact Day 30 contact lenses with a water content of 55% (P = 0.004). There was also significant thinning in the group wearing Conflex-air RGP contact lenses versus the group wearing Contact Day 30 soft contact lenses (P = 0.0005). CONCLUSIONS CCT was significantly thinner in patients wearing long-term low-Dk/t RGP contact lenses compared to no contact lens wear and soft contact lenses with a water content of 55%. CCT was also decreased significantly in long-term soft contact lens wear with a water content of 38% compared to 55%.
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Affiliation(s)
- Guzin Iskeleli
- From the Istanbul University, Cerrahpasa Faculty of Medicine, Department of Ophthalmology, Istanbul, Turkey.
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Kwok LS, Pierscionek BK, Bullimore M, Swarbrick HA, Mountford J, Sutton G. Orthokeratology for myopic children: wolf in sheep's clothing? Clin Exp Ophthalmol 2005; 33:343-7. [PMID: 16033342 DOI: 10.1111/j.1442-9071.2005.01059.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Orthokeratology attempts to reduce myopia by remoulding the corneal shape with contact lenses. A recent resurgence is predicated on new contact lens designs with a prefigured back contact surface and higher oxygen transmissibility. This Clinical Controversy presents an analysis of the risk factors associated with orthokeratology and its suitability for children, followed by commentaries from specialists who have an interest in the method. Some state that there is a lack of data on relative risks of corneal infection and that there is a need for large-scale randomized controlled studies; however, opinion is expressed by others that orthokeratology is a clinically safe procedure using modern lenses. It is noted that the physiological and biophysical bases of orthokeratology are virtually unknown, and further research on the human cornea is indicated to scientifically establish the safety of orthokeratology. Prospective patients, and their parents in the case of children, should be fully informed of the risks.
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Affiliation(s)
- L Stephen Kwok
- Department of Ophthalmology, Prince of Wales Hospital, The University of New South Wales, Sydney, New South Wales, Australia
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