1
|
Khanthik A, Kasetsuwan N, Yaisawang S, Reinprayoon U, Puangsricharern V, Satitpitakul V. Factors predicting the visual outcome of intracorneal ring segment for keratoconus. PLoS One 2024; 19:e0288181. [PMID: 38319899 PMCID: PMC10846708 DOI: 10.1371/journal.pone.0288181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 12/29/2023] [Indexed: 02/08/2024] Open
Abstract
OBJECTIVES To identify predictive factors and to construct predictive models using epidemiological and clinical preoperative factors for the visual acuity change after intracorneal ring segment (ICRS) implantation in patients with keratoconus. METHODS The medical records of 287 keratoconic eyes of 230 patients implanted with ICRS at Chula Refractive Surgery Center of a tertiary university hospital (Bangkok, Thailand) between January 2012 and March 2022 were retrospectively reviewed for epidemiological and clinical preoperative variables, including those derived from Scheimpflug tomography. After randomly excluding one eye for each bilateral case, the remaining 230 eyes were randomized into two groups: a training group (184 eyes) and a validation group (46 eyes). In the training group, the correlation between the interesting variables and postoperative uncorrected and corrected distance visual acuity change (ΔUDVA and ΔCDVA; logMAR scale) at 6 months was explored, and then the multiple linear regression analysis was used to develop the predictive models. The obtained models were tested using the validation group. RESULTS There were 5 and 14 preoperative variables that statistically correlated with ΔUDVA and ΔCDVA respectively. Only the preoperative corrected distance visual acuity (CDVAp) strongly correlated with ΔCDVA (Beta = -0.746). Using multiple regression, the preoperative uncorrected distance visual acuity (UDVAp) and front mean keratometry were selected in the proposed model for ΔUDVA (adjusted R2 = 38.8%), while the CDVAp and index of surface variance (ISV) were selected in the model [Formula: see text] (adjusted R2 = 48.9%). The ΔUDVA and ΔCDVA models were correct in 47.83% and 63.4% of the validation group within 0.20 logMAR, respectively. CONCLUSIONS Potential predictive factors and models for ICRS-induced changes in visual acuity are proposed as adjunctive tools for clinicians. Such tools could be used for case selection and during counselling before ICRS implantation to maximize surgical outcomes.
Collapse
Affiliation(s)
- Apisit Khanthik
- Faculty of Medicine, Department of Ophthalmology, Chulalongkorn University, Bangkok, Thailand
| | - Ngamjit Kasetsuwan
- Faculty of Medicine, Department of Ophthalmology, Chulalongkorn University, Bangkok, Thailand
- King Chulalongkorn Memorial Hospital and Faculty of Medicine, Department of Ophthalmology, Excellence Center of Cornea and Limbal Stem Cell Transplantation, Chulalongkorn University, Bangkok, Thailand
| | - Sasi Yaisawang
- Faculty of Medicine, Department of Ophthalmology, Chulalongkorn University, Bangkok, Thailand
| | - Usanee Reinprayoon
- Faculty of Medicine, Department of Ophthalmology, Chulalongkorn University, Bangkok, Thailand
- King Chulalongkorn Memorial Hospital and Faculty of Medicine, Department of Ophthalmology, Excellence Center of Cornea and Limbal Stem Cell Transplantation, Chulalongkorn University, Bangkok, Thailand
| | - Vilavun Puangsricharern
- Faculty of Medicine, Department of Ophthalmology, Chulalongkorn University, Bangkok, Thailand
- King Chulalongkorn Memorial Hospital and Faculty of Medicine, Department of Ophthalmology, Excellence Center of Cornea and Limbal Stem Cell Transplantation, Chulalongkorn University, Bangkok, Thailand
| | - Vannarut Satitpitakul
- Faculty of Medicine, Department of Ophthalmology, Chulalongkorn University, Bangkok, Thailand
- King Chulalongkorn Memorial Hospital and Faculty of Medicine, Department of Ophthalmology, Excellence Center of Cornea and Limbal Stem Cell Transplantation, Chulalongkorn University, Bangkok, Thailand
| |
Collapse
|
2
|
Khanjian AT, Ivanova AV, Sklyarova AS, Khodzhabekyan NV, Manukyan IV. [Comparative analysis of clinical and functional parameters in patients with stable stage II-III keratoconus after implantation of corneal segments and fitting of scleral rigid contact lenses]. Vestn Oftalmol 2024; 140:72-77. [PMID: 38742501 DOI: 10.17116/oftalma202414002172] [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] [Indexed: 05/16/2024]
Abstract
The modern treatment strategy for keratoconus (KC) involves sequential application of medical technologies aimed at stabilizing pathological changes in the cornea and restoring visual acuity. PURPOSE This study compares the effect of implantation of intrastromal corneal ring segment (ICRS) and fitting of individual scleral rigid contact lenses (RCLs) on visual functions in patients with stage II-III KC after previously performed corneal collagen cross-linking. MATERIAL AND METHODS The Helmholtz National Medical Research Center of Eye Diseases examined and treated 34 patients (69 eyes) aged 18 to 33 years with stage II-III KC. The study included patients who had previously undergone standard corneal collagen cross-linking. Depending on the type of optical correction, the patients were divided into two groups: patients in group 1 underwent ICRS implantation using a femtosecond laser; patients in group 2 were fitted with individual scleral RCLs. RESULTS Improvement in clinical and functional parameters was observed in both groups. A higher clinical and functional result was achieved in group 2. CONCLUSION For patients with stable stage II-III KC, it is advisable to recommend fitting of individual scleral RCLs for visual rehabilitation.
Collapse
Affiliation(s)
- A T Khanjian
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - A V Ivanova
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - A S Sklyarova
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - N V Khodzhabekyan
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| | - I V Manukyan
- Helmholtz National Medical Research Center of Eye Diseases, Moscow, Russia
| |
Collapse
|
3
|
Liu Y, Shen D, Wang HY, Qi MY, Zeng QY. Development and validation to predict visual acuity and keratometry two years after corneal crosslinking with progressive keratoconus by machine learning. Front Med (Lausanne) 2023; 10:1146529. [PMID: 37534322 PMCID: PMC10393251 DOI: 10.3389/fmed.2023.1146529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/16/2023] [Indexed: 08/04/2023] Open
Abstract
Purpose To explore and validate the utility of machine learning (ML) methods using a limited sample size to predict changes in visual acuity and keratometry 2 years following corneal crosslinking (CXL) for progressive keratoconus. Methods The study included all consecutive patients with progressive keratoconus who underwent CXL from July 2014 to December 2020, with a 2 year follow-up period before July 2022 to develop the model. Variables collected included patient demographics, visual acuity, spherical equivalence, and Pentacam parameters. Available case data were divided into training and testing data sets. Three ML models were evaluated based on their performance in predicting case corrected distance visual acuity (CDVA) and maximum keratometry (Kmax) changes compared to actual values, as indicated by average root mean squared error (RMSE) and R-squared (R2) values. Patients followed from July 2022 to December 2022 were included in the validation set. Results A total of 277 eyes from 195 patients were included in training and testing sets and 43 eyes from 35 patients were included in the validation set. The baseline CDVA (26.7%) and the ratio of steep keratometry to flat keratometry (K2/K1; 13.8%) were closely associated with case CDVA changes. The baseline ratio of Kmax to mean keratometry (Kmax/Kmean; 20.9%) was closely associated with case Kmax changes. Using these metrics, the best-performing ML model was XGBoost, which produced predicted values closest to the actual values for both CDVA and Kmax changes in testing set (R2 = 0.9993 and 0.9888) and validation set (R2 = 0.8956 and 0.8382). Conclusion Application of a ML approach using XGBoost, and incorporation of identifiable parameters, considerably improved variation prediction accuracy of both CDVA and Kmax 2 years after CXL for treatment of progressive keratoconus.
Collapse
Affiliation(s)
- Yu Liu
- Aier School of Ophthalmology, Central South University, Changsha, China
- Aier Eye Hospital of Wuhan University, Wuhan, China
| | - Dan Shen
- Aier Eye Hospital of Wuhan University, Wuhan, China
| | - Hao-yu Wang
- Aier Eye Hospital of Wuhan University, Wuhan, China
| | - Meng-ying Qi
- Aier Eye Hospital of Wuhan University, Wuhan, China
| | - Qing-yan Zeng
- Aier School of Ophthalmology, Central South University, Changsha, China
- Aier Eye Hospital of Wuhan University, Wuhan, China
- Aier Cornea Institute, Beijing, China
- Aier School of Ophthalmology and Optometry, Hubei University of Science and Technology, Xianning, China
| |
Collapse
|
4
|
Coskunseven E, Kayhan B. Asymmetric intracorneal ring segments in the treatment of snowman phenotype keratoconus. J Fr Ophtalmol 2023; 46:510-517. [PMID: 36890076 DOI: 10.1016/j.jfo.2022.11.012] [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: 09/04/2022] [Revised: 10/13/2022] [Accepted: 11/11/2022] [Indexed: 03/08/2023]
Abstract
OBJECTIVE To evaluate refractive, aberrometric, topographic, and topometric outcomes of asymmetric intracorneal ring segment (ICRS) implantation in snowman phenotype (asymmetric bow-tie) keratoconus. METHODS This retrospective, interventional study included eyes with snowman phenotype keratoconus. Two asymmetric ICRSs (Keraring AS) were implanted after femtosecond laser-assisted tunnel formation. Visual, refractive, aberrometric, topographic, and topometric changes after asymmetric ICRS implantation were evaluated with a mean follow-up of 11 months (6-24 months). MAIN RESULTS Seventy-one eyes were analyzed in the study. Keraring AS implantation corrected refractive errors significantly. The mean spherical error decreased from -5.06±4.23 D to -1.62±3.45 D (P=0.001), and the mean cylindrical error decreased from -5.43±2.48 D to -2.44±1.49 D (P=0.001). Uncorrected distance visual acuity improved from 0.98±0.80 to 0.46±0.46 Log MAR (P=0.001), and corrected distance visual acuity improved from 0.58±0.56 to 0.17±0.39 Log MAR (P=0.001). Keratometry (K) maximum, K1, K2, K mean, astigmatism, and corneal asphericity (Q-value) showed a significant decrease (P=0.001). Vertical coma aberration decreased significantly from -3.31±2.12μm to -2.56±1.94μm (P=0.001). All topometric indices of corneal irregularities were significantly reduced postoperatively (P=0.001). CONCLUSIONS Keraring AS implantation in snowman phenotype keratoconus demonstrated good efficacy and safety. Clinical, topographic, topometric, and aberrometric parameters improved significantly after Keraring AS implantation.
Collapse
Affiliation(s)
- E Coskunseven
- Département de chirurgie réfractive, hôpital Dunyagoz Etiler, Istanbul, Turkey; Faculté des sciences de la santé, université Rumeli d'Istanbul, Istanbul, Turkey
| | - B Kayhan
- Département de chirurgie réfractive, hôpital Dunyagoz Etiler, Istanbul, Turkey; Département d'ophtalmologie, Sultan II, hôpital de formation et de recherche Abdulhamid Han, université des sciences de la santé, Istanbul, Turkey.
| |
Collapse
|
5
|
Coskunseven E, Kayhan B. Clinical, tomographic, and topometric outcomes of progressive thickness intracorneal ring segment implantations in duck-type keratoconus. Indian J Ophthalmol 2022; 70:2939-2945. [PMID: 35918949 DOI: 10.4103/ijo.ijo_2770_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Purpose To evaluate the visual, refractive, tomographic, and topometric outcomes of progressive thickness intracorneal ring segment (PT-ICRS) implantation in duck-type keratoconus. Methods This retrospective study included eyes with oval (duck-type) keratoconus treated with PT-ICRS implantation. After the femtosecond laser tunnel creation, one PT-ICRS (Keraring AS 5 with 160° arc length) was implanted along the ectatic, inferior half of the cornea. Data of uncorrected and corrected distance visual acuity (UDVA and CDVA), refraction, asphericity (Q value), and keratometry (K) were compared pre- and postoperatively. Additionally, changes in the topometric indices of corneal irregularity were also evaluated after PT-ICRS implantation. Results Thirty-one eyes of 30 patients were included in the study with a mean follow-up time of 9.06 months (ranging between 6 and 18 months). UDVA improved from 0.85 ± 0.36 to 0.27 ± 0.14 logMAR (P = 0.001), and CDVA improved from 0.37 ± 0.22 to 0.13 ± 0.11 logMAR (P = 0.001). The mean spherical error decreased from -3.66 ± 2.60 to -1.60 ± 1.42 D (P = 0.001), and the mean cylindrical error decreased from -4.91 ± 2.65 to - 1.41 ± 1.31 D (P = 0.001). All topographic parameters measured from the anterior cornea demonstrated statistically significant improvements after PT-ICRS implantation (P = 0.001). K mean, K maximum, corneal astigmatism, and Q value showed a significant decrease. Besides the index of height asymmetry, all topometric indices were significantly reduced after PT-ICRS implantation. There were no loss of lines and no complications. Conclusion PT-ICRS implantation in duck-type keratoconus is an effective and safe treatment. This intervention improves the visual acuity, refractive error, topographical, and topometric parameters significantly by decreasing both eccentricity and steepness of the cone.
Collapse
Affiliation(s)
- Efekan Coskunseven
- Department of Refractive Surgery, Dunyagoz Etiler Hospital; Faculty of Health Sciences, Istanbul Rumeli University, Istanbul, Turkey
| | - Belma Kayhan
- Department of Refractive Surgery, Dunyagoz Etiler Hospital; Department of Ophthalmology, Sultan II. Abdulhamid Han Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| |
Collapse
|
6
|
Clinical evaluation of the effectiveness of asymmetric intracorneal ring with variable thickness and width for the management of keratoconus. J Cataract Refract Surg 2021; 47:722-730. [PMID: 33278234 DOI: 10.1097/j.jcrs.0000000000000525] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 11/07/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the short-term clinical outcomes obtained with a new model of asymmetric intracorneal ring segments (ICRS) with variable thickness and base width in keratoconus. SETTING Four ophthalmologic centers in Spain. DESIGN Prospective multicenter longitudinal noncomparative clinical trial. METHODS Thirty-one keratoconus eyes of 25 patients (aged 15 to 50 years) that underwent implantation of ICRS of variable thickness and base (AJL-pro+) in 4 Spanish centers were enrolled. Visual, refractive, topographic, aberrometric, and pachymetric changes were evaluated during a 3-month follow-up. Complications were also recorded. RESULTS Statistically significant changes after surgery were observed in uncorrected distance visual acuity (P = .002) and corrected distance visual acuity (CDVA) (P = .005), as well as in spherical equivalent (P = .006). At 3 months postoperatively, no loss of 2 or more lines of CDVA was observed, whereas 48.4% (15) of eyes gained ≥1 line. Statistically significant changes were observed in the steepest and mean keratometric values (P ≤ .047) and in the magnitude of astigmatism (P < .001) of both anterior and posterior corneal surfaces. Likewise, a change to a less prolate shape of the anterior surface was found (P = .011). Primary coma was also reduced significantly at 1 month postoperatively (P = .001, mean reduction 40.1%). No serious implant-related complications occurred during the follow-up. CONCLUSIONS The implantation of intrastromal asymmetric ring segments of variable thickness and base width in keratoconus corneas induces a significant anterior corneal flattening, leading to refractive changes, a significant reduction of its prolate shape and irregularity, and improvement in patient CDVA.
Collapse
|
7
|
Baptista PM, Ambrosio R, Oliveira L, Meneres P, Beirao JM. Corneal Biomechanical Assessment with Ultra-High-Speed Scheimpflug Imaging During Non-Contact Tonometry: A Prospective Review. Clin Ophthalmol 2021; 15:1409-1423. [PMID: 33854295 PMCID: PMC8039844 DOI: 10.2147/opth.s301179] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/05/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND In recent years, increasing interest has arisen in the application of data from corneal biomechanics in many areas of ophthalmology, particularly to assist in the detection of early corneal ectasia or ectasia susceptibility, to predict corneal response to surgical or therapeutic interventions and in glaucoma management. Technology has evolved and, recently, the Scheimpflug principle was associated with a non-contact air-puff tonometer, allowing a thorough analysis of corneal biomechanics and a biomechanically corrected intraocular pressure assessment, opening up new perspectives both in ophthalmology and in other medical areas. Data from corneal biomechanics assessment are being integrated in artificial intelligence models in order to increase its value in clinical practice. OBJECTIVE To review the state of the art in the field of corneal biomechanics assessment with special emphasis to the technology based on ultra-high-speed Scheimpflug imaging during non-contact tonometry. SUMMARY A meticulous literature review was performed until the present day. We used 136 published manuscripts as our references. Both information from healthy individuals and descriptions of possible associations with systemic diseases are described. Additionally, it exposed information regarding several fields of ocular pathology, from cornea and ocular surface through areas of refractive surgery and glaucoma until vascular and structural diseases of the chorioretinal unit.
Collapse
Affiliation(s)
- Pedro Manuel Baptista
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal
| | - Renato Ambrosio
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, RJ, Brazil
- Department of Cornea and Refractive Surgery, Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Department of Opthalmology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Federal University of São Paulo (UNIFESP), São Paulo, Brazil
- Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil
| | - Luis Oliveira
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Pedro Meneres
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal
| | - Joao Melo Beirao
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal
| |
Collapse
|
8
|
Larco P, Larco P, Torres D, Piñero DP. Intracorneal Ring Segment Implantation for the Management of Keratoconus in Children. Vision (Basel) 2020; 5:1. [PMID: 33374847 PMCID: PMC7838879 DOI: 10.3390/vision5010001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 12/10/2020] [Accepted: 12/22/2020] [Indexed: 11/17/2022] Open
Abstract
The short-term safety and efficacy of intracorneal ring segment (ICRS) implantation in keratoconus eyes of children are investigated in this study. A retrospective interventional case series study including a total of 33 keratoconus eyes (age 8 to 17 years) that had undergone ICRS (Keraring segments, Mediphacos) implantation was conducted. Information about visual, refractive, pachymetric, corneal topographic and aberrometric, and corneal endothelial changes during a 3-month follow-up were extracted and analysed. A significant improvement was observed in logMAR corrected distance visual acuity (p = 0.005), combined with a statistically significant reduction in keratometric readings (p < 0.001). A reduction in the magnitude of corneal astigmatism of ≥1 D was observed in 52.8% of eyes. No significant changes were observed in corneal endothelial density (p = 0.317). Significant changes were found in the anterior vertical coma component (p = 0.002) as well as in the spherical aberration of the posterior corneal surface (p = 0.004). Only two relevant complications were described: one corneal microperforation with penetration of the ring segment into the anterior chamber (1 eye, 2.8%), and a case of ring extrusion (1 eye, 2.8%). ICRS implantation in children keratoconus eyes allows a reduction of corneal astigmatism, irregularity, and aberrations, leading to a significant visual improvement.
Collapse
Affiliation(s)
- Pablo Larco
- Clínica Larco Visión, Quito 170135, Ecuador; (P.L.); (P.L.J.); (D.T.)
| | - Pablo Larco
- Clínica Larco Visión, Quito 170135, Ecuador; (P.L.); (P.L.J.); (D.T.)
| | - Daniel Torres
- Clínica Larco Visión, Quito 170135, Ecuador; (P.L.); (P.L.J.); (D.T.)
| | - David P. Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain
| |
Collapse
|
9
|
Koh IH, Seo KY, Park SB, Yang H, Kim I, Kim JS, Hwang DG, Nam SM. One-Year Efficacy and Safety of Combined Photorefractive Keratectomy and Accelerated Corneal Collagen Cross-Linking after Intacs SK Intracorneal Ring Segment Implantation in Moderate Keratoconus. BIOMED RESEARCH INTERNATIONAL 2019; 2019:7850216. [PMID: 31360724 PMCID: PMC6644267 DOI: 10.1155/2019/7850216] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/24/2019] [Indexed: 11/17/2022]
Abstract
PURPOSE To report one-year outcomes of a modified version of two-stage multimodal surgical protocol for moderate keratoconus which has been suggesting promising preliminary results. MATERIALS AND METHODS 30 eyes of 25 patients with moderate keratoconus who exhibited visual complaints and/or disease progression were included for this retrospective case study. Approximately 3 months after implantation of intracorneal ring segment (Intacs SK™), a combination of corneal wavefront-guided transepithelial photorefractive keratectomy (CWG-transPRK, Schwind Amaris® 1050, and Schwind Sirius) and accelerated collagen cross-linking (accCXL, Avedro KXL™) was performed. Patients were examined for uncorrected and corrected distance visual acuity (UDVA; CDVA), keratometric power (K), corneal thickness, and corneal higher-order aberrations (HOAs) preoperatively and at postoperative 1, 3, 6, and 12 months. RESULTS The median UDVA and mean CDVA were enhanced from 6/38 to 6/12 and from 6/19 to 6/7.5, respectively, through 12 months after CWG-transPRK/accCXL. The 12-month CDVA of all patients was better than 6/12 Snellen, and no subject lost one or more lines of CDVA. The magnitudes of both myopia and corneal steepness were decreased in turn by Intacs SK implantation and also by CWG-transPRK/accCXL, but the reduction in HOA was largely the result of CWG-transPRK/accCXL. The magnitude of corneal thinning stabilized within 3 months after CWG-transPRK/accCXL. CONCLUSION This approach may allow patients with moderate keratoconus to obtain satisfactory vision without the need for contact lens wear. This surgery appeared to be effective and safe through 1 year of follow-up.
Collapse
Affiliation(s)
- Il Hwan Koh
- SU Yonsei Eye Clinic, Seoul, Republic of Korea
| | - Kyoung Yul Seo
- Department of Ophthalmology, Institute of Vision Research, Eye and Ear Hospital, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | - Hun Yang
- SU Yonsei Eye Clinic, Seoul, Republic of Korea
| | - InSik Kim
- SU Yonsei Eye Clinic, Seoul, Republic of Korea
| | - Jin Sun Kim
- SU Yonsei Eye Clinic, Seoul, Republic of Korea
| | - David G. Hwang
- Cornea Service and Refractive Surgery Service, Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
| | - Sang Min Nam
- Department of Ophthalmology, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| |
Collapse
|