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Liu B, Shang X, Tan X, Luo S, Fang X, Xie Z, Xiao X, He H, Gong L, Wu H, Lin Z. Clinical and Morphological in Vivo Confocal Microscopy Findings following a Modified Biphasic Higher Fluence Transepithelial Corneal Crosslinking. Curr Eye Res 2024; 49:119-130. [PMID: 37882774 DOI: 10.1080/02713683.2023.2276680] [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: 08/03/2023] [Accepted: 10/03/2023] [Indexed: 10/27/2023]
Abstract
Purpose: To compare the refractive efficacy and morphological changes in the cornea following a novel biphasic higher fluence transepithelial corneal crosslinking (BI-TE-CXL) and transepithelial corneal crosslinking (TE-CXL) in adults keratoconus.Methods: Patients with progressive keratoconus who required corneal crosslinking were assigned to the BI-TE-CXL group (32 eyes, phase 1: 7.2 J/cm2 for 5 min and 20 s of pulsed-light exposure, KXL, Glaukos-Avedro; phase 2: 3.6 J/cm2 for 6 min and 40 s of continuous light exposure at the front curvature apex with a 6 mm diameter light spot, UVX-2000, IROC) or the TE-CXL group (32 eyes, uniform 7.2 J/cm2 for 5 min and 20 s of pulsed-light exposure, KXL, Glaukos-Avedro). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal fluorescein staining (CFS), corneal topography, anterior segment optical coherence tomography (AS-OCT), and in vivo corneal confocal microscopy (IVCM) were performed 3, 6, 12 and 24 months after surgery.Results: The CFS scores in the BI-TE-CXL group were significantly higher than those in the TE-CXL group on the first two days after surgery (p < 0.001). The Kmax (at 12 and 24 months) and CDVA (logMAR) were significantly lower in the BI-TE-CXL group than those in the TE-CXL group (p < 0.05). The corneal demarcation line under AS-OCT was visible in 81.3% of patients in the BI-TE-CXL group and 15.6% in the TE-CXL group. The depth of the demarcation line under IVCM was significantly deeper in the BI-TE-CXL group (248.3 ± 25.0 μm) than that of the TE-CXL group (136.5 ± 15.6 μm) in the central cornea (p < 0.001). The cross-linked collagen structures in the central cornea were still present after 12 months in the BI-TE-CXL group. No significant difference in sub-basal nerve density between the two groups (p > 0.05).Conclusions: Following BI-TE-CXL, CDVA was significantly improved, accompanied by deeper demarcation line depth and persistent crosslinked structures in the central corneal stroma.
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Affiliation(s)
- Bin Liu
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, Fujian, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Xumin Shang
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Xiuxian Tan
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, Fujian, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Shunrong Luo
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Xie Fang
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Zhiwen Xie
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Xianwen Xiao
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Huan He
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, Fujian, China
| | - Lan Gong
- Department of Ophthalmology, Eye, Ear, Nose, and, Throat Hospital of Fudan University, Shanghai, China
| | - Huping Wu
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, Fujian, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
| | - Zhirong Lin
- Eye Institute and Affiliated Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Xiamen, Fujian, China
- Fujian Key Laboratory of Ocular Surface & Corneal Diseases (affiliated Xiamen Eye Center of, Xiamen University), Xiamen, Fujian, China
- Xiamen Municipal Key Laboratory of Ocular Surface & Corneal Diseases, Xiamen, Fujian, China
- Xiamen Research Center for Eye Diseases and Key Laboratory of Ophthalmology, Xiamen, Fujian, China
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Xanthopoulou K, Milioti G, Daas L, Munteanu C, Seitz B, Flockerzi E. Accelerated Corneal Crosslinking for Treatment of Keratoconus in Children and Adolescents under 18 Years of Age. Klin Monbl Augenheilkd 2023; 240:1131-1142. [PMID: 36436508 DOI: 10.1055/a-1933-3084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate the efficacy of accelerated (9 mW/cm2, 10 min) epithelium-off (epi-off) corneal crosslinking (A-CXL) in keratoconus (KC) patients < 18 years of age. PATIENTS AND METHODS Our retrospective study included 41 eyes (25 male and 5 female patients, mean age 15.3 ± 1.2 years) who underwent A-CXL (9 mW/cm2, 10 min) because of progressive KC or critical KC at first presentation or asymmetrical finding in the partner eye. Outcome measures were best-corrected visual acuity (BCVA) and tomography readings (Pentacam HR, Oculus, Wetzlar, Germany), evaluated 2 years, 1 year, 6 months preoperatively, prior to surgery (pre-CXL) and 6 weeks, 6 months, 1 year, 2 years, > 2 years postoperatively (post-CXL). The demarcation line was assessed by anterior segment optical coherence tomography (SS-1000 and CASIA 2, Tomey, Nagoya, Japan). RESULTS Total deviation value increased statistically significantly 6 months pre-CXL to pre-CXL. Anterior steep, flat, and mean keratometry values showed a statistically significant increase 6 weeks post-CXL (p < 0.05), followed by a significant decrease until 2 years post-CXL for steep and mean keratometry. Kmax increased 6 weeks post-CXL without statistical significance and decreased significantly even > 2 years post-CXL (p < 0.0001). Posterior keratometry as well as anterior and posterior astigmatism did not show any significant changes post-CXL. Thinnest and apical pachymetry decreased significantly until 6 months post-CXL (p < 0.05) and remained stable > 2 years post-CXL (p > 0.05). BCVA decreased 6 weeks post-CXL but improved significantly > 2 years post-CXL (p = 0.003). The demarcation line reached an average depth of 52.1%. CONCLUSIONS Epi-off A-CXL stabilizes KC progression in patients < 18 years even > 2 years postoperatively and leads to a deep demarcation line. A "pseudoprogression" is observed up to the 6-week follow-up, which is not indicative of the long-term results.
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Affiliation(s)
- Kassandra Xanthopoulou
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
| | - Georgia Milioti
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
| | - Loay Daas
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
| | - Cristian Munteanu
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
| | - Elias Flockerzi
- Department of Ophthalmology, Saarland University Medical Center and Saarland University Faculty of Medicine, Homburg/Saar, Germany
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Muacevic A, Adler JR. A Comparison Between Cross-Linking Protocols in Patients With Progressive Keratoconus: A Review. Cureus 2022; 14:e31029. [PMID: 36475196 PMCID: PMC9718644 DOI: 10.7759/cureus.31029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2022] [Indexed: 01/25/2023] Open
Abstract
Keratoconus (KC) is a noninflammatory cornea disease leading to progressive thinning, causing it to change from its normal dome shape to a cone shape. One of the novel treatments of KC is corneal collagen cross-linking (CXL). Due to its importance, many studies have been conducted to compare corneal cross-linking protocols; this review article aims to discuss corneal cross-linking and compare its different treatment options, including Dresden, accelerated, and customized protocols in patients with progressive KC and their respective long-term outcomes. A search was performed in PubMed and Google Scholar with no language, dates, or study type restriction. Most of the results showed almost no difference between protocols over traditional cross-linking. However, published data are limited, long-term outcomes of novel age groups remain unclear, and further studies are needed.
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Somohano K, Alzaga-Fernandez AG. Controversies in Corneal Collagen Crosslinking: A Review of Investigational Crosslinking Protocols and Its Off-label Application. Int Ophthalmol Clin 2022; 62:51-62. [PMID: 36170222 DOI: 10.1097/iio.0000000000000426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Brekelmans J, Dickman MM, Verma S, Arba‐Mosquera S, Goldschmidt R, Goz A, Brandis A, Berendschot TT, Saelens IE, Marcovich AL, Scherz A, Nuijts RM. Excimer laser-assisted corneal epithelial pattern ablation for corneal cross-linking. Acta Ophthalmol 2022; 100:422-430. [PMID: 34533277 PMCID: PMC9291225 DOI: 10.1111/aos.15021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/31/2021] [Accepted: 08/31/2021] [Indexed: 11/29/2022]
Abstract
Purpose To determine corneal cross‐linking (CXL) efficacy and chromophore penetration after excimer laser‐assisted patterned de‐epithelialization. Methods Two‐hundred‐twenty porcine eyes were de‐epithelialized ex vivo, either fully (mechanical; n = 88) or patterned (excimer laser; n = 132). Consecutively, corneas were impregnated with hypo‐ or hyperosmolar riboflavin (RF; n = 20, RF‐D; n = 40, respectively) or water‐soluble taurine (WST11; n = 40, and WST‐D; n = 40, respectively), or kept unimpregnated (n = 80). Sixty corneas were subsequently irradiated, inducing CXL, with paired contralateral eyes serving as controls. Outcome measurements included strip extensiometry to assess CXL efficacy, and spectrophotometry and fluorescence microscopy to determine stromal chromophore penetration. Results All tested chromophores induced significant CXL (p < 0.001), ranging from 7.6% to 14.6%, with similar stiffening for all formulations (p = 0.60) and both de‐epithelialization methods (p = 0.56). Light transmittance was significantly lower (p < 0.001) after full compared with patterned de‐epithelialization. Stromal chromophore penetration was comparable between fully and patterned de‐epithelialized samples, with full penetration in RD and RF‐D samples and penetration depths measuring 591.7 ± 42.8 µm and 592.9 ± 63.5 µm for WST11 (p = 0.963) and 504.2 ± 43.2 µm and 488.8 ± 93.1 µm for WST‐D (p = 0.669), respectively. Conclusions Excimer laser‐assisted patterned de‐epithelialization allows for effective CXL. Stromal chromophore concentration is, however, reduced, which may have safety implications given the need for sufficient UVA attenuation in RF/UVA CXL. The different safety profile of near‐infrared (NIR) may allow safe WST11/NIR CXL even with reduced stromal chromophore concentration values. In vivo studies are needed to evaluate the benefits and further assess safety of excimer laser‐assisted patterned de‐epithelialization for corneal CXL.
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Affiliation(s)
- Jurriaan Brekelmans
- University Eye Clinic Maastricht Maastricht University Medical Center Maastricht the Netherlands
- Department of Plant Science and Environmental Health the Weizmann Institute of Science Rehovot Israel
| | - Mor M. Dickman
- University Eye Clinic Maastricht Maastricht University Medical Center Maastricht the Netherlands
| | - Shwetabh Verma
- Department of Research and Development SCHWIND Eye‐Tech‐Solutions Kleinostheim Germany
- Experimental Radiation Oncology University Medical Center Mannheim Heidelberg Germany
- Interdisciplinary Center for Scientific Computing (IWR) Heidelberg University Heidelberg Germany
- Central Institute for Computer Engineering (ZITI) Heidelberg University Heidelberg Germany
| | - Samuel Arba‐Mosquera
- Department of Research and Development SCHWIND Eye‐Tech‐Solutions Kleinostheim Germany
| | - Ruth Goldschmidt
- Department of Plant Science and Environmental Health the Weizmann Institute of Science Rehovot Israel
| | - Alexandra Goz
- Department of Plant Science and Environmental Health the Weizmann Institute of Science Rehovot Israel
- Department of Ophthalmology Kaplan Medical Center Rehovot Israel
| | - Alexander Brandis
- Department of Biological Services the Weizmann Institute of Science Rehovot Israel
| | - Tos T.J.M. Berendschot
- University Eye Clinic Maastricht Maastricht University Medical Center Maastricht the Netherlands
| | - Isabelle E.Y. Saelens
- University Eye Clinic Maastricht Maastricht University Medical Center Maastricht the Netherlands
| | - Arie L. Marcovich
- Department of Plant Science and Environmental Health the Weizmann Institute of Science Rehovot Israel
- Department of Ophthalmology Kaplan Medical Center Rehovot Israel
| | - Avigdor Scherz
- Department of Plant Science and Environmental Health the Weizmann Institute of Science Rehovot Israel
| | - Rudy M.M.A. Nuijts
- University Eye Clinic Maastricht Maastricht University Medical Center Maastricht the Netherlands
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Sun L, Zhao J, Zhang X, Shen Y, Tian M, Zhou X. Transepithelial accelerated corneal crosslinking for keratoconus eyes with maximum keratometry values larger than 58 diopters. J Cataract Refract Surg 2022; 48:208-214. [PMID: 34288636 PMCID: PMC8845528 DOI: 10.1097/j.jcrs.0000000000000733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/26/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the safety and efficacy of transepithelial accelerated corneal crosslinking (CXL) for advanced keratoconus eyes with maximum keratometry (Kmax) values >58 diopters (D). SETTING Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China. DESIGN Prospective parallel control study. METHODS 41 keratoconus eyes from 41 patients (mean age, 21.93 ± 5.48 years) who underwent transepithelial accelerated CXL were included prospectively. The enrolled eyes were divided into 2 groups according to their Kmax values (Group A, Kmax ≥58.0 D; Group B, Kmax <58.0 D). The examinations including assessment of uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), corneal topography, and corneal endothelial cell density count were conducted preoperatively, at 1 day, 1 month, 3 months, 6 months, and 1 year postoperatively. RESULTS All 41 eyes finished 1 year follow-up. No statistical difference was noted between the mean UDVA and CDVA in both groups throughout the follow-up duration. At 1-year postoperative follow-up, the CDVA increased by ≥2 lines in 45% (9/20) and 28.6% (6/21) eyes in Groups A and B, respectively. The mean preoperative Kmax in Groups A and B were 62.51 ± 3.34 D and 49.98 ± 4.32 D, respectively, and that at postoperative 1-year follow-up were 61.94 ± 4.11 D and 50.24 ± 4.72 D, respectively. The Kmax values of 30% (6/20) eyes in Group A and 4.8% (1/21) eyes in Group B decreased by more than 1 D. Deduction of flat K, steep K, mean K, and Kmax showed no significant difference between the 2 groups at 1-year postoperative follow-up. Moreover, 20% (4/20) and 23.8% (5/21) of eyes in Groups A and B, respectively, showed progress at postoperative 1-year follow-up. CONCLUSIONS Transepithelial accelerated CXL can safely treat advanced keratoconus eyes with Kmax values ≥58.0 D with some extent of efficacy and has similar progressive rate as Kmax values <58.0 D.
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Preliminary Characterization of Predictive Factors of the Visual Change after Epi-On and Epi-Off Corneal Collagen Crosslinking Techniques. J Ophthalmol 2021; 2021:9680253. [PMID: 34917415 PMCID: PMC8670975 DOI: 10.1155/2021/9680253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 11/04/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose To investigate the potential predictive factors of the visual change achieved with accelerated epi-on and epi-off corneal collagen crosslinking (CXL) in keratoconus. Methods This retrospective comparative study analyzed 67 eyes treated with an accelerated epithelium-on (epi-on group) and epithelium-off (epi-off group) CXL. The clinical outcomes were evaluated and compared during a 1-year follow-up. Likewise, the relationship of the change achieved with both CXL techniques in the corrected distance visual acuity (CDVA) with different preoperative data was investigated. Results The mean CDVA change at 3 months postoperatively was −0.04 ± 0.19 and −0.07 ± 0.25 in the epi-on and epi-off groups, respectively (p = 0.809). In the epi-on group, this change was significantly correlated with the preoperative apical (r = −0.375, p = 0.045) and central corneal thickness (r = −0.402, p = 0.031). In the epi-off group, the CDVA change was significantly correlated with not only the preoperative apical (r = 0.402, p = 0.028) and central corneal thickness (r = 0.367, p = 0.046) but also with some topometric and aberrometric indices (r ≤ −0.374, p ≤ 0.042). Furthermore, the change in CDVA in the epi-on group could be predicted from age, preoperative refractive astigmatism J45 component, anterior corneal asphericity, and posterior corneal high order aberration root mean square (p = 0.002, R2 = 0.503). In the epi-off group, the CDVA change could be predicted from the preoperative minimum corneal thickness and magnitude of the vertical anterior corneal primary coma component (p = 0.001, R2 = 0.446). Conclusions Clearly, different predictive factors of the visual change induced with the accelerated epi-on and epi-off CXL techniques are present, suggesting a different mechanism of action for stiffening the cornea and inducing changes in this structure.
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D'Oria F, Palazón A, Alio JL. Corneal collagen cross-linking epithelium-on vs. epithelium-off: a systematic review and meta-analysis. EYE AND VISION (LONDON, ENGLAND) 2021; 8:34. [PMID: 34565473 PMCID: PMC8465763 DOI: 10.1186/s40662-021-00256-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 08/08/2021] [Indexed: 01/08/2023]
Abstract
BACKGROUND The purpose of the study was to determine the advantages and disadvantages of epi-on corneal cross-linking (CXL) techniques compared with standard epi-off CXL. METHODS We searched MEDLINE and EMBASE for randomized controlled trials (RCTs) and non-randomized studies of interventions (NRSIs) and we evaluated the selected papers according to the Cochrane risk of bias tool. We considered, as primary outcomes, average Kmax flattening, changes in uncorrected and corrected distance visual acuity (UDVA and CDVA); as secondary outcomes, we considered changes in pachymetry values and endothelial cell density (ECD). We also investigated adverse events related to the treatments and treatment failure. Meta-analysis was conducted with a fixed or random-effects model using weighted mean difference (MD) with 95% confidence interval (CI) as the effect size. RESULTS A total of 15 studies were included and among these 15 trials, 9 were RCTs and 6 were NRSIs, but only 4 studies showed no high risk of bias and were included in this meta-analysis. Our analysis revealed significant postoperative differences in CDVA (MD = 0.07; 95% CI 0.04 to 0.10; P < 0.001), and no significative differences in UDVA, Kmax, central corneal thickness (CCT) and ECD (P > 0.05). Epi-on CXL protocol was found to be significantly less prompt to have risks of delay in epithelial healing (P = 0.035) and persistent stromal haze (P = 0.026). CONCLUSION Epi-on CXL is as effective as epi-off CXL. Except for a higher significant improvement in CDVA with current epi-on protocols, our meta-analysis demonstrates that epi-on and epi-off CXL have comparable effects on visual, topographic, pachymetric, and endothelial parameters. Epi-on CXL has clinical advantages in terms of comfort and avoidance of complications as it reduces the risk of developing delay in epithelial healing and persistent stromal haze.
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Affiliation(s)
- Francesco D'Oria
- Vissum Innovation, c/ Cabañal, 1, 03016, Alicante, Spain
- Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
- Section of Ophthalmology, Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari, Bari, Italy
| | - Antonio Palazón
- Department of Clinical Medicine, Miguel Hernández University, San Juan de Alicante, Spain
| | - Jorge L Alio
- Vissum Innovation, c/ Cabañal, 1, 03016, Alicante, Spain.
- Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain.
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Ouyang BW, Ding H, Wang H, Yang ZD, Zhong T, Fan HM, Zhong XW. Comparison of corneal biological parameters between transepithelial and epithelium-off corneal cross-linking in keratoconus. Int J Ophthalmol 2021; 14:998-1005. [PMID: 34282383 DOI: 10.18240/ijo.2021.07.06] [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: 07/11/2020] [Accepted: 04/08/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the differences in corneal biological parameters between transepithelial and epithelium-off corneal cross-linking in keratoconus. METHODS In our prospective clinical trial, 40 patients (60 eyes) with progressive keratoconus were randomized to undergo corneal cross-linking with transepithelial (TE group, n=30) or epithelium-off (EO group, n=30) keratoconus. Examinations comprised topography, corneal biomechanical analysis and specular microscopy at 6mo postoperatively. RESULTS The keratometer values were not significantly different between the TE and EO corneal cross-linked groups in different periods (each P>0.05). The corneal thickness of the EO group was greater than that of the TE group at 1wk after the operation (each P<0.05). Regarding corneal biomechanical responses, the EO group showed a longer second applanation length than TE group (P=0.003). Regarding the corneal endothelial function, standard deviation of the endothelial cell size, and coefficient of variation in the cell area, the values of EO group were larger than those of TE group at 1wk (P=0.011, 0.026), and the percentage of hexagonal cells in EO group was lower than that in TE group at 1 and 6mo (P=0.018, 0.019). CONCLUSION Epithelium-off corneal cross-linking may strengthen corneal biomechanics better than TE procedure can. However, the TE procedure with a lower ultraviolet-A irradiation intensity would be safer for corneal endothelial function.
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Affiliation(s)
- Bo-Wen Ouyang
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China
| | - Hui Ding
- Hainan Eye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou 570311, Hainan Province, China
| | - Han Wang
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China
| | - Zhen-Duo Yang
- Hainan Eye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou 570311, Hainan Province, China
| | - Tan Zhong
- Hainan Eye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou 570311, Hainan Province, China
| | - Hong-Ming Fan
- Hainan Eye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou 570311, Hainan Province, China
| | - Xing-Wu Zhong
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China.,Hainan Eye Hospital, Zhongshan Ophthalmic Center, Sun Yat-sen University, Haikou 570311, Hainan Province, China
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Comparison of Contact Lens Assisted and Transepithelial Corneal Cross Linking with Standard 'Epithelium Off' Cross Linking for Progressive Keratoconus: 24 Month Clinical Results. J Cataract Refract Surg 2021; 48:199-207. [PMID: 34174043 DOI: 10.1097/j.jcrs.0000000000000732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/14/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare outcomes of contact lens assisted corneal cross linking (CACXL) and transepithelial corneal cross linking (TECXL) with standard 'epithelium off'' ('epi -off') cross linking (CXL) for progressive keratoconus. SETTING Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh , India. DESIGN Retrospective, comparative study. METHODS Patients with progressive keratoconus undergoing CXL with a minimum follow up of 24 months were included. CACXL and TECXL was performed in patients with 'epithelium on' minimal pachymetry between 350 µm to 450 µm. Main outcome measures included change in maximum keratometry (Kmax), corrected distance visual acuity (CDVA), and efficacy in halting progression (increase in Kmax ≥ 1 diopter [D]). RESULTS Standard 'epi -off' CXL, CACXL and TECXL was performed in 34,14 and 10 eyes respectively. Baseline Kmax and CDVA were comparable for all groupsKmax reduced significantly by -2.83 ± 3.35 D, -3.18 ± 2.74D and -2.02 ± 1.66 D in standard 'epi-off' CXL (p<0.01), CACXL (p=0.001) and TECXL (p=0.004) groups respectively; the reduction was comparable for all groups (p=0.63). CDVA improved by -0.14 ± 0.24 , -0.04 ± 0.19 and -0.12 ± 0.17 logMAR units in the standard 'epi -off' CXL (p =0.006), CACXL (p=0.42) and TECXL (p=0.05) groups respectively; the reduction was comparable for all groups (p=0.46). Progression was documented in 2 eyes (6%) of the standard 'epi -off' CXL group and 0% eyes of the CACXL and TECXL groups (p=0.61). CONCLUSIONS CACXL and TECXL were comparable to standard 'epi -off' CXL for progressive keratoconus.
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Arance-Gil Á, Villa-Collar C, Pérez-Sanchez B, Carracedo G, Gutiérrez-Ortega R. Epithelium-Off vs. transepithelial corneal collagen crosslinking in progressive keratoconus: 3 years of follow-up. JOURNAL OF OPTOMETRY 2021; 14:189-198. [PMID: 32883647 PMCID: PMC8093524 DOI: 10.1016/j.optom.2020.07.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 06/30/2020] [Accepted: 07/15/2020] [Indexed: 05/07/2023]
Abstract
PURPOSE To compare the efficacy of epithelium-off corneal collagen crosslinking (CXL) with transepithelial CXL in patients with progressive keratoconus with a follow-up of 3 years, taking into account the patients' age and the location of the corneal ectasia. METHODS In this prospective study participated 64 eyes with progressive keratoconus were included in this long-term study, of which 31 eyes were treated by epithelium-off CXL and 33 by transepithelial CXL. All of the patients with a follow-up of 36 months were evaluated for visual variables (corrected distance visual acuity (CDVA), corneal aberrations, and corneal densitometry), structure variables (astigmatism, keratometry, corneal asphericity, maximum posterior elevation, corneal thickness, and corneal volume), and keratoconus index variables. RESULTS After corneal CXL, CDVA improved significantly in both central and paracentral keratoconus, with greater improvement in the centrals (p = 0.001), asphericity at 6 mm improved in central keratoconus (p = 0.047). In the epi-off group, there was a significant improvement in coma-like (p = 0.038), higher-order aberrations (p = 0.036), asphericity at 8 mm (p = 0.049), asphericity at 10 mm (p = 0.049), and index of surface variance (p = 0.049). CONCLUSION Although both techniques halted and stabilized the progression of keratoconus, epithelium-off CXL was more effective. In addition, after the corneal CXL, there was a greater degree of regularization of the corneal surface and, therefore, a greater improvement in the CDVA with central keratoconus than with paracentral keratoconus.
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Affiliation(s)
| | - César Villa-Collar
- Clínica Novovisión, Madrid, Spain; Department of Pharmacy, Biotechnology, Nutrition, Optics and Optometry, Faculty of Biomedical and Health Sciences, European University of Madrid, Madrid, Spain.
| | - Belén Pérez-Sanchez
- Department of Statistics, Mathematics and Informatics, Miguel Hernández University, Elche, Spain.
| | - Gonzalo Carracedo
- Department of Optometry and Vision, Faculty of Optic and Optometry, Complutense University of Madrid, Madrid, Spain.
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Ng SM, Ren M, Lindsley KB, Hawkins BS, Kuo IC. Transepithelial versus epithelium-off corneal crosslinking for progressive keratoconus. Cochrane Database Syst Rev 2021; 3:CD013512. [PMID: 33765359 PMCID: PMC8094622 DOI: 10.1002/14651858.cd013512.pub2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Keratoconus is the most common corneal dystrophy. It can cause loss of uncorrected and best-corrected visual acuity through ectasia (thinning) of the central or paracentral cornea, irregular corneal scarring, or corneal perforation. Disease onset usually occurs in the second to fourth decade of life, periods of peak educational attainment or career development. The condition is lifelong and sight-threatening. Corneal collagen crosslinking (CXL) using ultraviolet A (UVA) light applied to the cornea is the only treatment that has been shown to slow progression of disease. The original, more widely known technique involves application of UVA light to de-epithelialized cornea, to which a photosensitizer (riboflavin) is added topically throughout the irradiation process. Transepithelial CXL is a recently advocated alternative to the standard CXL procedure, in that the epithelium is kept intact during CXL. Retention of the epithelium offers the putative advantages of faster healing, less patient discomfort, faster visual rehabilitation, and less risk of corneal haze. OBJECTIVES To assess the short- and long-term effectiveness and safety of transepithelial CXL compared with epithelium-off CXL for progressive keratoconus. SEARCH METHODS To identify potentially eligible studies, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2020, Issue 1); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature database (LILACS); ClinicalTrials.gov; and World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not impose any date or language restrictions. We last searched the electronic databases on 15 January 2020. SELECTION CRITERIA We included randomized controlled trials (RCTs) in which transepithelial CXL had been compared with epithelium-off CXL in participants with progressive keratoconus. DATA COLLECTION AND ANALYSIS We used standard Cochrane methodology. MAIN RESULTS We included 13 studies with 723 eyes of 578 participants enrolled; 13 to 119 participants were enrolled per study. Seven studies were conducted in Europe, three in the Middle East, and one each in India, Russia, and Turkey. Seven studies were parallel-group RCTs, one study was an RCT with a paired-eyes design, and five studies were RCTs in which both eyes of some or all participants were assigned to the same intervention. Eleven studies compared transepithelial CXL with epithelium-off CXL in participants with progressive keratoconus. There was no evidence of an important difference between intervention groups in maximum keratometry (denoted 'maximum K' or 'Kmax'; also known as steepest keratometry measurement) at 12 months or later (mean difference (MD) 0.99 diopters (D), 95% CI -0.11 to 2.09; 5 studies; 177 eyes; I2 = 41%; very low certainty evidence). Few studies described other outcomes of interest. The evidence is very uncertain that epithelium-off CXL may have a small (data from two studies were not pooled due to considerable heterogeneity (I2 = 92%)) or no effect on stabilization of progressive keratoconus compared with transepithelial CXL; comparison of the estimated proportions of eyes with decreases or increases of 2 or more diopters in maximum K at 12 months from one study with 61 eyes was RR 0.32 (95% CI 0.09 to 1.12) and RR (non-event) 0.86 (95% CI 0.74 to 1.00), respectively (very low certainty). We did not estimate an overall effect on corrected-distance visual acuity (CDVA) because substantial heterogeneity was detected (I2 = 70%). No study evaluated CDVA gain or loss of 10 or more letters on a logarithm of the minimum angle of resolution (logMAR) chart. Transepithelial CXL may result in little to no difference in CDVA at 12 months or beyond. Four studies reported that either no adverse events or no serious adverse events had been observed. Another study noted no change in endothelial cell count after either procedure. Moderate certainty evidence from 4 studies (221 eyes) found that epithelium-off CXL resulted in a slight increase in corneal haze or scarring when compared to transepithelial CXL (RR (non-event) 1.07, 95% CI 1.01 to 1.14). Three studies, one of which had three arms, compared outcomes among participants assigned to transepithelial CXL using iontophoresis versus those assigned to epithelium-off CXL. No conclusive evidence was found for either keratometry or visual acuity outcomes at 12 months or later after surgery. Low certainty evidence suggests that transepithelial CXL using iontophoresis results in no difference in logMAR CDVA (MD 0.00 letter, 95% CI -0.04 to 0.04; 2 studies; 51 eyes). Only one study examined gain or loss of 10 or more logMAR letters. In terms of adverse events, one case of subepithelial infiltrate was reported after transepithelial CXL with iontophoresis, whereas two cases of faint corneal scars and four cases of permanent haze were observed after epithelium-off CXL. Vogt's striae were found in one eye after each intervention. The certainty of the evidence was low or very low for the outcomes in this comparison due to imprecision of estimates for all outcomes and risk of bias in the studies from which data have been reported. AUTHORS' CONCLUSIONS Because of lack of precision, frequent indeterminate risk of bias due to inadequate reporting, and inconsistency in outcomes measured and reported among studies in this systematic review, it remains unknown whether transepithelial CXL, or any other approach, may confer an advantage over epithelium-off CXL for patients with progressive keratoconus with respect to further progression of keratoconus, visual acuity outcomes, and patient-reported outcomes (PROs). Arrest of the progression of keratoconus should be the primary outcome of interest in future trials of CXL, particularly when comparing the effectiveness of different approaches to CXL. Furthermore, methods of assessing and defining progressive keratoconus should be standardized. Trials with longer follow-up are required in order to assure that outcomes are measured after corneal wound-healing and stabilization of keratoconus. In addition, perioperative, intraoperative, and postoperative care should be standardized to permit meaningful comparisons of CXL methods. Methods to increase penetration of riboflavin through intact epithelium as well as delivery of increased dose of UVA may be needed to improve outcomes. PROs should be measured and reported. The visual significance of adverse outcomes, such as corneal haze, should be assessed and correlated with other outcomes, including PROs.
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Affiliation(s)
- Sueko M Ng
- Department of Ophthalmology, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Mark Ren
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kristina B Lindsley
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands
| | - Barbara S Hawkins
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Irene C Kuo
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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13
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Safety and efficacy of repeated crosslinking assisted by transepithelial double-cycle iontophoresis in keratoconus progression after primary corneal crosslinking. Eye (Lond) 2021; 35:3020-3027. [PMID: 33414527 PMCID: PMC8526808 DOI: 10.1038/s41433-020-01365-1] [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: 08/17/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVES To evaluate the safety and efficacy of repeated corneal collagen crosslinking assisted by transepithelial double-cycle iontophoresis (DI-CXL) in the management of keratoconus progression after primary CXL. METHODS A retrospective analysis was conducted in the patients who underwent repeated CXL between 2016 and 2018. These patients were treated with DI-CXL if keratoconus progression was confirmed after primary CXL. Scoring of ocular pain and corneal epithelial damage, visual acuity, corneal tomography, in vivo corneal confocal microscopy (IVCM) was performed before and at 3, 6, 12, and 24 months after DI-CXL. RESULTS Overall, 21 eyes of 12 patients (mean age 17.3 ± 1.9 years) were included in this study. Before DI-CXL, an average increase of 4.26 D in Kmax was detected in these patients with a mean follow-up interval of (23.0 ± 13.7) months. After DI-CXL, corneal epithelial damage rapidly recovered within days. Visual acuity remained unchanged with follow-up of 24 months. When compared to baseline, significant decreases were observed in Kmax (at 3 months) and K2 (at 3 and 6 months) after DI-CXL. Corneal thickness of thinnest point significantly decreased at 3 months postoperatively. When compared to baseline, no significant differences were found in any of the refractive or tomographic parameters at 12 and 24 months. IVCM revealed trabecular patterned hyperdense tissues after DI-CXL in the anterior stroma at the depth of 200 μm or more. No corneal infiltration or persistent epithelial defect was recorded after DI-CXL. CONCLUSION DI-CXL is safe and effective as a good alternative in stabilizing keratoconus progression after primary CXL.
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Santhiago MR, Randleman JB. The biology of corneal cross-linking derived from ultraviolet light and riboflavin. Exp Eye Res 2020; 202:108355. [PMID: 33171194 DOI: 10.1016/j.exer.2020.108355] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/12/2020] [Accepted: 11/04/2020] [Indexed: 12/01/2022]
Abstract
Over the past 20 years, corneal crosslinking (CXL) has been used by surgeons to halt progression in eyes with keratoconus. We reviewed the literature regarding the mechanism of action of CXL, the role of each of its components the strong biologic reaction, and their effects on cell interaction, proteins involved, wound healing, and cytotoxic reaction. CXL surgery involves a photochemical response in which ultraviolet light at a given wavelength and riboflavin participate. The combination of irradiation with UVA light and riboflavin leads to an intense process of apoptosis of keratocytes in the anterior stroma. Differences in light irradiation, as well as the importance of riboflavin and its vehicle, were also detailed. The surgery creates additional chemical bonds between the amino terminals of the collagen side chains and the proteoglycans of the extracellular matrix. A photosensitization reaction catalyzed by riboflavin classically involves the production of singlet oxygen. Microstructure studies show changes in the size of the fibril and potentially in the interfibrillar space, that the most significant changes related to the stiffening effect of CXL occur in the anterior third of the cornea and that short irradiation times, especially below 5 min, may not have the same biological effect. Changes in the riboflavin vehicle, with the incorporation of Hydroxypropyl methylcellulose as a carrier, can lead to faster diffusion and a more intense photochemical reaction. These are findings that can impact the optimal adjustment of irradiation time according to the riboflavin (and its carrier) used. Many studies have suggested that CXL is safe and effective in the standard and accelerated protocols that have been used by surgeons. After the initial depletion of anterior keratocytes, keratocyte density seems to return to average 6-12 months after surgery when corneas are examined with the confocal microscope.
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Affiliation(s)
- Marcony R Santhiago
- University of São Paulo, São Paulo, SP, Brazil; University of Southern California, Los Angeles, CA, USA.
| | - J Bradley Randleman
- Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, USA; Cole Eye Institute, Cleveland Clinic, USA
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15
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Ghaffari SR, Khaheshi S, Alipour F, Mashhadi Farahani S, Beheshtnejad AH, Hafezi F. Reduced fluence corneal cross-linking in mild to moderate keratoconus: One year-follow-up. Eur J Ophthalmol 2020; 31:2206-2212. [PMID: 33092399 DOI: 10.1177/1120672120966560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To evaluate the safety and efficacy of reduced fluence CXL (lower dose of UV-A irradiation) in mild to moderate keratoconus. SETTING Farabi Eye Hospital, Tehran, Iran. DESIGN Non-randomized prospective comparative interventional case series. Every eligible patient included in the study (mild to moderate progressive keratoconus) was randomly allocated to case (reduced fluence) and control (standard) groups, except for bilateral patients. In these patients the eye with more advanced disease was allocated to control group and the other eye was randomly assigned in either case or control group. Operators performing refraction and images and the data analyst were masked, but patients and physicians were not. METHODS Forty-six eyes of 38 patients were recruited. Group 1 received 7 min (fluence of 3.8 J/cm2), while group 2 received 10 min of 9 mW/cm2 UV-A (fluence of 5.4 J/cm2). Visual, keratometric and biomechanical outcomes were compared between groups. RESULTS At last follow-up (mean12 months, range 6-24 months), there were no statistically significant differences in changes in uncorrected visual acuity, best corrected distance visual acuity, Kmax, Kmean, corneal hysteresis, corneal resistance factor, endothelial cell counts, demarcation line depth, and intraoperative pain scores between groups (all p-values < 0.05). CONCLUSION The results of this study show comparable one-year outcomes between 3.8 and 5.4 J/cm2 accelerated CXL in mild to moderate keratoconus. Should the results of this study be confirmed in longer follow-ups, using a reduced fluence setting could be considered as an alternative to standard treatment in these patients.
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Affiliation(s)
- Seyed Reza Ghaffari
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Saeed Khaheshi
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Fateme Alipour
- Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | | | | | - Farhad Hafezi
- Department of Ophthalmology, Geneva University Hospitals, Geneva, Switzerland.,ELZA Institute, Dietikon, Switzerland.,Department of Ophthalmology, University of Wenzhou, Wenzhou, China
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Zaheryani SMS, Movahedan H, Salouti R, Mohaghegh S, Javadpour S, Shirvani M, Kasraei F, Bamdad S. Corneal Collagen Cross-Linking Using Epithelium Disruptor Instrument in Progressive Keratoconus. J Curr Ophthalmol 2020; 32:256-262. [PMID: 32775800 PMCID: PMC7382520 DOI: 10.4103/joco.joco_59_20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/24/2020] [Accepted: 03/31/2020] [Indexed: 11/10/2022] Open
Abstract
Purpose: To compare the effects of accelerated corneal collagen cross-linking (CXL) in progressive keratoconus (KCN) patients via epithelium removal and transepithelial techniques, using Daya Disruptor (Duckworth and Kent, Hertfordshire, UK). Methods: This study is a double-blinded, randomized clinical trial. Patients with documented bilateral progressive KCN were randomized into two groups: one eye underwent epithelium removal (Group 1), and the fellow eye underwent epithelium disruption (Group 2). The primary outcomes were best corrected visual acuity (BCVA) and uncorrected visual acuity (UCVA), Scheimpflug-extracted keratometric indices, and anterior segment-optical coherence tomography-derived epithelial thickness profiles. These parameters were evaluated before and 12 months after CXL. Results: Sixty-four eyes from 34 patients with progressive KCN (34 eyes in the epithelium-removal group and 30 eyes in the epithelium-disruption group) were included. The mean ± standard deviation (SD) of age was 23.4 ± 3.8 years in the epithelium-removal group and 23.2 ± 3.5 years in the epithelium-disruption group. The mean ± SD of the preoperative spherical equivalent (SE), front maximum keratometry (K-max), back K-max, thickness of thinnest point, and corneal apex thickness were − 2.9 ± 3.0 diopter (D) and − 3.7 ± 3.1 D (P = 0.183), 53.8 ± 5.15 D and 54.4 ± 5.53 D (P = 0.653), −6.63 ± 2.40 D and − 6.68 ± 2.48 D (P = 0.131), 459.2 ± 37.4 μm and 460.8 ± 32.7 μm (P = 0.708), 470.5 ± 37.7 μm and 469.7 ± 33.1 μm (P = 0.679), and 55.4 ± 4.97 μm and 54.6 ± 7.16 μm (P = 0.767) in the epithelium-removal and epithelium-disruption groups, respectively. The mean ± SD changes of the UCVA and BCVA 12 months after CXL were − 0.1 ± 0.11 and − 0.02 ± 0.18 and − 0.04 ± 0.12 and − 0.02 ± 0.14 in the epithelium-removal and epithelium-disruption groups, respectively. No statistically significant improvement was observed in the UCVA and BCVA between the two groups (P = 0.868 and P = 0.937, respectively). The mean ± SD changes of the SE, superior epithelial thickness, corneal apex thickness, and thickness of thinnest point 12 months after CXL were − 0.21 ± 1.1 D and + 0.32 ± 1.6 D (P = 0.0001), −0.08 ± 0.26 μm and + 0.03 ± 0.33 μm (P = 0.028), −23 ± 11 μm and − 2 ± 6 μm (P = 0.0001), and − 25 ± 8 μm and − 3 ± 7 μm (P = 0.0001) in the epithelium-removal and epithelium-disruption groups, respectively. Conclusions: This study showed that the epithelium-disruption CXL using Daya has a similar potential for halting KCN progression as the epithelium-removal CXL. However, regarding the 12-month changes, the epithelium-disruption CXL is superior to the epithelium-removal CXL in the SE and corneal pachymetry.
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Affiliation(s)
- Seyed Mohammad Salar Zaheryani
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Ophthalmology, Urmia University of Medical Sciences, Bukan, Iran
| | - Hossein Movahedan
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ramin Salouti
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sahar Mohaghegh
- Department of Optometry, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sara Javadpour
- Department of Cardiology, Deputy of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Shirvani
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farzaneh Kasraei
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Shahram Bamdad
- Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Transepithelial corneal cross-linking assisted by two continuous cycles of iontophoresis for progressive keratoconus in adults: retrospective 5-year analysis. Graefes Arch Clin Exp Ophthalmol 2020; 259:239-246. [PMID: 32725404 PMCID: PMC7790794 DOI: 10.1007/s00417-020-04861-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/18/2020] [Accepted: 07/23/2020] [Indexed: 10/25/2022] Open
Abstract
PURPOSE The aim of this study is to compare the long-term effects of transepithelial corneal crosslinking with two continuous cycles of iontophoresis (EI-CXL) and conventional corneal crosslinking (C-CXL) in adults with progressive keratoconus. METHODS A retrospective analysis was conducted in adults who underwent C-CXL or EI-CXL between 2013 and 2015. Visual acuity, corneal tomography, anterior segment optical coherence tomography, in vivo corneal confocal microscopy (IVCM), and endothelial cell count (ECC) were performed preoperatively and 5 years postoperatively. RESULTS Sixty-eight patients with a mean age of (24.3 ± 3.8) years were included, 34 for each group. After CXL, UCVA or BCVA remained stable, while the spherical diopter, cylinder diopter, spherical equivalent, and Kmax significantly decreased at 1, 2, and 3 years in both groups than baseline (P < 0.05). No significant differences were found in any refractive or tomographic parameters as well as the minimal corneal thickness between groups during follow-up. At 5 years, Kmax was slightly higher in EI-CXL group (58.16 ± 6.28) than that of C-CXL group (57.46 ± 4.98). At 3 and 5 years, the minimal corneal thickness in C-CXL group was still significantly lower than baseline (P < 0.05). IVCM demonstrated the demarcation zone at a mean depth of (302.0 ± 41.7) μm after C-CXL, and at (251.2 ± 28.1) μm after EI-CXL (P < 0.001). Keratocyte repopulation was detectable at all follow-up timepoint in both groups. Postoperative complications including progression were recorded in 6 patients (11.7%) after C-CXL and 3 patients (8.8%) after EI-CXL. ECC remained stable in both groups. CONCLUSION EI-CXL showed approximate efficacy with C-CXL in stabilizing progressive keratoconus in adults. EI-CXL has the potential to be a preferable transepithelial protocol.
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Zhang X, Sun L, Tian M, Shen Y, Li M, Zhao J, Zhou X. Accelerated (45 mW/cm 2) Transepithelial Corneal Cross-Linking for Progressive Keratoconus Patients: Long-Term Topographical and Clinical Outcomes. Front Med (Lausanne) 2020; 7:283. [PMID: 32637419 PMCID: PMC7318888 DOI: 10.3389/fmed.2020.00283] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 05/21/2020] [Indexed: 11/30/2022] Open
Abstract
Aims: We characterized long-term clinical outcomes of accelerated (45 mW/cm2) transepithelial corneal cross-linking (ATE-CXL) for the treatment of progressive keratoconus. Methods: Forty-two eyes from 37 patients treated for keratoconus were observed. ATE-CXL was performed using riboflavin and pulsed-light ultraviolet treatment (45 mW/cm2, 7.2 J/cm2). Structural and functional measurements were made after 1 week and 1, 3, 6, 12, 24, 36, and 48 months subsequently. Corneal topographic parameters were observed using Scheimpflug topography (Pentacam software). Results: Surgery was uneventful in all subjects. Mean uncorrected (UDVA) and corrected distance visual acuity (CDVA) (logMAR) were 0.99 ± 0.58 and 0.44 ± 0.27 (P = 0.022), 0.24 ± 0.29 and 0.27 ± 0.35 (P = 0.601), at baseline and last follow-up, respectively. The pre-operative mean maximum keratometry (Kmax) value was 57.29 ± 9.13 diopters (D), and the thinnest corneal thickness (TCT) was 456.21 ± 44.66 μm. Mean Kmax was 56.67 ± 9.36 D, 4 years post-operatively (P = 0.781). TCT changed to 453.17 ± 46.76 μm at 4 years post-operatively (P = 0.780). Multiple linear regression indicated that patients with thinner pre-operative TCT (≤ 450 μm) showed decreasing post-operative average keratometry (Kavg) and increasing post-operative TCT. Patients with posterior central elevation (PCE) >80 μm showed decreasing post-operative Kavg as well as post-operative PCE. No complications were observed during follow-up. Conclusion: Stabilization after ATE-CXL was achieved for the treatment of keratoconus. The clinical efficacy of ATE-CXL in advanced keratoconus patients with thin corneal thickness and greater PCE will require further investigation.
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Affiliation(s)
- Xiaoyu Zhang
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Department of Ophthalmology, The Eye and ENT Hospital of Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Ling Sun
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Department of Ophthalmology, The Eye and ENT Hospital of Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Mi Tian
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Department of Ophthalmology, The Eye and ENT Hospital of Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yang Shen
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Department of Ophthalmology, The Eye and ENT Hospital of Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Meiyan Li
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Department of Ophthalmology, The Eye and ENT Hospital of Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Jing Zhao
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Department of Ophthalmology, The Eye and ENT Hospital of Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xingtao Zhou
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Department of Ophthalmology, The Eye and ENT Hospital of Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
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Corneal Cross-linking: Epi-On vs. Epi-Off Current Protocols, Pros, and Cons. CURRENT OPHTHALMOLOGY REPORTS 2020. [DOI: 10.1007/s40135-020-00241-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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20
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Kuo IC, Hawkins BS, Ren M, Lindsley KB. Transepithelial versus epithelium-off corneal crosslinking for progressive keratoconus. Hippokratia 2020. [DOI: 10.1002/14651858.cd013512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Irene C Kuo
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine; Department of Ophthalmology; 4924 Campbell Blvd #100 Baltimore Maryland USA 21236
| | - Barbara S Hawkins
- The Johns Hopkins University School of Medicine; Wilmer Eye Institute; 550 North Broadway, 9th floor Baltimore Maryland USA 21205-2010
| | - Mark Ren
- The Johns Hopkins University School of Medicine; Wilmer Eye Institute; 550 North Broadway, 9th floor Baltimore Maryland USA 21205-2010
| | - Kristina B Lindsley
- IBM Watson Health; Life Sciences, Oncology, & Genomics; Baltimore Maryland USA
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21
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Toker E, Çerman E, Özcan DÖ, Seferoğlu ÖB. Efficacy of different accelerated corneal crosslinking protocols for progressive keratoconus. J Cataract Refract Surg 2019; 43:1089-1099. [PMID: 28917412 DOI: 10.1016/j.jcrs.2017.05.036] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 05/30/2017] [Accepted: 05/31/2017] [Indexed: 11/27/2022]
Abstract
PURPOSE To evaluate the efficacy of different accelerated corneal crosslinking (CXL) treatment protocols in patients with progressive keratoconus. SETTING Marmara University School of Medicine, Istanbul, Turkey. DESIGN Retrospective case series. METHODS Patients with progressive keratoconus had 9 mW accelerated CXL (10 minutes; 9 mW/cm2), 30 mW continuous-light accelerated CXL (4 minutes; 30 mW/cm2), or 30 mW pulsed-light accelerated CXL (8 minutes [1 second on/1 second off]; 30 mW/cm2). RESULTS Of 134 eyes, 34 eyes had conventional CXL, 45 had 9 mW accelerated CXL, 28 had 30 mW continuous-light accelerated CXL (4 minutes, 30 mW/cm2), and 27 eyes had 30 mW pulsed-light accelerated CXL. The uncorrected (UDVA) (P < .001 both) and corrected (CDVA) distance visual acuities increased in with conventional CXL and 9 mW accelerated CXL (P = .001 and P = .002, respectively). With 30 mW continuous accelerated CXL, only CDVA improved (P = .019). With 30 mW pulsed accelerated CXL, UDVA and CDVA did not change significantly (P > .05). With conventional CXL and 9 mW accelerated CXL, all keratometric (K) readings (K1, K2, mean K, maximum K) improved significantly (conventional CXL: P = .014, P = .002, P = .008, and P < .001, respectively; 9 mW accelerated CXL: all P < .001). With 30 mW, no K values changed significantly compared with baseline (all groups P > .05). CONCLUSION Although 30 mW accelerated CXL treatment modalities appeared to be effective in stabilizing keratoconus progression, they seemed less effective in achieving topographic improvement.
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Affiliation(s)
- Ebru Toker
- From the Department of Ophthalmology, Marmara University School of Medicine, Istanbul, Turkey.
| | - Eren Çerman
- From the Department of Ophthalmology, Marmara University School of Medicine, Istanbul, Turkey
| | - Deniz Özarslan Özcan
- From the Department of Ophthalmology, Marmara University School of Medicine, Istanbul, Turkey
| | - Özge Begüm Seferoğlu
- From the Department of Ophthalmology, Marmara University School of Medicine, Istanbul, Turkey
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22
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Hersh PS, Lai MJ, Gelles JD, Lesniak SP. Transepithelial corneal crosslinking for keratoconus. J Cataract Refract Surg 2019; 44:313-322. [PMID: 29703286 DOI: 10.1016/j.jcrs.2017.12.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 11/17/2017] [Accepted: 12/10/2017] [Indexed: 12/13/2022]
Abstract
PURPOSE To evaluate outcomes of corneal crosslinking (CXL) using a transepithelial technique for the treatment of keratoconus. SETTING Cornea and refractive surgery subspecialty practice. DESIGN Prospective case series. METHODS Transepithelial CXL was performed in keratoconic eyes using riboflavin 0.1% and topical anesthetic containing benzalkonium chloride to facilitate riboflavin diffusion through the epithelium. Eyes were randomized to receive riboflavin administration either every 1 minute or every 2 minutes during ultraviolet-A exposure at 3mW/cm2. The principal outcome was change in maximum keratometry (K) and secondary outcomes included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, mean K, and comparison of randomized groups. RESULTS Eighty-two eyes of 56 patients were treated. At 1 year, maximum K decreased significantly by 0.45 diopters (D) ± 1.94 (SD); it improved by 2.0 D or more in 11 eyes (13%) and worsened by 2.0 D or more in 4 eyes (5%). The mean UDVA significantly improved by 0.7 lines, whereas the CDVA improved by 0.2 lines. Two eyes showed both continued progression with loss of CDVA. Only the 1-minute subgroup showed significant improvements in maximum K (-0.73 D) and UDVA. Transient corneal erosion and epitheliopathy were reported in 21% of eyes. CONCLUSIONS Transepithelial CXL resulted in significant improvements in maximum K and UDVA over 1 year. There was a suggestion that increased riboflavin dosing might improve procedure outcomes. Further study is required to determine the relative advantages and disadvantages of different transepithelial approaches to the standard CXL protocol with epithelial removal.
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Affiliation(s)
- Peter S Hersh
- From the Cornea and Laser Eye Institute-Hersh Vision Group (Hersh), CLEI Center for Keratoconus (Hersh, Lai, Gelles), Teaneck, and the Department of Ophthalmology, Rutgers-New Jersey Medical School (Hersh, Lesniak), Newark, New Jersey, USA.
| | - Michael J Lai
- From the Cornea and Laser Eye Institute-Hersh Vision Group (Hersh), CLEI Center for Keratoconus (Hersh, Lai, Gelles), Teaneck, and the Department of Ophthalmology, Rutgers-New Jersey Medical School (Hersh, Lesniak), Newark, New Jersey, USA
| | - John D Gelles
- From the Cornea and Laser Eye Institute-Hersh Vision Group (Hersh), CLEI Center for Keratoconus (Hersh, Lai, Gelles), Teaneck, and the Department of Ophthalmology, Rutgers-New Jersey Medical School (Hersh, Lesniak), Newark, New Jersey, USA
| | - Sebastian P Lesniak
- From the Cornea and Laser Eye Institute-Hersh Vision Group (Hersh), CLEI Center for Keratoconus (Hersh, Lai, Gelles), Teaneck, and the Department of Ophthalmology, Rutgers-New Jersey Medical School (Hersh, Lesniak), Newark, New Jersey, USA
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23
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Corneal crosslinking: Current protocols and clinical approach. J Cataract Refract Surg 2019; 45:1670-1679. [DOI: 10.1016/j.jcrs.2019.06.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/19/2019] [Accepted: 06/21/2019] [Indexed: 12/18/2022]
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24
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Valera-Cornejo DA, Vega-Estrada A, Alio JL. Invasive Pharmacology Outcomes with Different Corneal Cross-Linking Protocols: A Review. J Ocul Pharmacol Ther 2019; 35:475-490. [DOI: 10.1089/jop.2018.0144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
| | - Alfredo Vega-Estrada
- Miguel Hernandez University, Alicante, Spain
- VIssum Ophthalmic Corporation, Alicante, Spain
| | - Jorge L. Alio
- Miguel Hernandez University, Alicante, Spain
- VIssum Ophthalmic Corporation, Alicante, Spain
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25
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Hernandez-Camarena JC, Graue-Hernandez EO, Loya-García D, Ruiz-Lozano RE, Valdez-García JE. Correlation between corneal stromal demarcation line depth and topographic outcomes after two pulsed-light-accelerated crosslinking protocols. Clin Ophthalmol 2019; 13:1665-1673. [PMID: 31507315 PMCID: PMC6720021 DOI: 10.2147/opth.s206103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/24/2019] [Indexed: 11/23/2022] Open
Abstract
Purpose To report the visual and topographic outcomes of two pulsed-light-accelerated CXL (A-CXL) protocols at a 12-month follow-up and their correlation with the corneal stromal demarcation line (DL) depth. Patients and methods Retrospective comparative cohort of patients with documented progressive keratoconus were included. Two epi-off pulsed-light [1s on–1s off] A-CXL protocols were compared: irradiance 30*8 and 45*5:20 (fluence 7.2 J/cm2). UDVA, CDVA, spherical equivalent (SE), topographic astigmatism, Kmin, Kmax, Km, central corneal thickness (CCT), thinnest pachymetry (TCT) and endothelial cell density (ECD) were measured preoperatively and months 1, 3, 6 and 12 postoperative. Corneal DL was measured 1 month postoperatively using anterior segment optical coherence tomography. Results Fifty eyes (27 patients): 22 eyes in group A-CXL (30*8), 28 eyes in group A-CXL (45*5:20). Mean age (years) was 19.04±4.71 and 20.32±4.57. DL depth (µm) at month 1 was 200.63±10.01 µm and 184.53±19.68 µm for group A-CXL (30*8) and group A-CXL (45*5:20), respectively (p<0.001). Significant improvement in CDVA, topographic astigmatism, Kmin, Kmax and Km was observed in both groups (no significant difference between groups) and no significant changes were observed in CCT, TCT and ECD with regard to baseline. Over 85% of the eyes in both protocols achieved stabilization or improvement in maximum K at the end of the follow-up. No significant correlations between DL and any visual or topographic outcomes were observed at 12 months. Conclusion No correlation between DL depth and visual or topographic outcomes was observed on either protocol. Although significant improvement on CDVA, topographic astigmatism, Kmin, Kmax and Km was observed in both groups at 12 months, further research is needed to assure safety and effectiveness at stabilizing keratoconus progression.
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Affiliation(s)
| | - Enrique O Graue-Hernandez
- Department of Cornea and Refractive Surgery, Institute of Ophthalmology Conde de Valenciana, Mexico City, Mexico
| | - Denise Loya-García
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, NL 64710, Mexico
| | - Raul E Ruiz-Lozano
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, NL 64710, Mexico
| | - Jorge E Valdez-García
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, NL 64710, Mexico
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26
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Kopaenko AI, Ivanova NV. [Transepithelial corneal collagen crosslinking in patients with progressive keratoconus]. Vestn Oftalmol 2019; 134:42-47. [PMID: 29771883 DOI: 10.17116/oftalma2018134242-47] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To assess the effectiveness of transepithelial collagen crosslinking (CXL) in patients with keratoconus. MATERIAL AND METHODS The study involved 44 patients (44 eyes) with stage I-II progressive keratoconus. Patients were divided into two groups. The 1st group included 22 patients that had underwent transepithelial CXL. The 2nd group included 22 patients that had underwent traditional CXL. RESULTS AND DISCUSSION All patients of the group 2 all patients had corneal syndrome, which lasted 2-4 days. In the 1st group, 98% of the patients did not have corneal syndrome and their visual acuity (VA) was same as preoperative on the next day after the surgery. In the 2nd group, the mean level of postoperative pain was 1.7 times higher than in group 1 (p<0.05). Six months after the treatment, uncorrected VA (UCVA) in the 1st group has increased by 52%, the best corrected VA (BCVA) - by 17%, in the 2nd group UCVA increased by 53%, BCVA - by 20% (p<0.05). The demarcation line in the 2nd group was 2.2 times deeper than in the 1st group (p<0.05). Six months after the treatment in the 1st group mean K1, K2 and Km decreased by 1.5%, 2.3% and 1.7% respectively (p>0.05); in the 2nd group - by 3.6%, 3.9% and 4.1% (p<0.05) compared with the data before the surgery. One year after the treatment, mean Kmax in the 1st group decreased by 2.1%, in the 2nd group - by 3.9%. Differences with preoperative values were statistically significant only in the 2nd group. CONCLUSION Transepitelial CXL is a safe procedure well tolerated by patients and leading to a rapid restoration of visual function. Transepithelial CXL proved to have reduced effectiveness in inducing improvement in keratometric values, its effect on visual acuity was likely to be similar to that of epithelium-off CXL.
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Affiliation(s)
- A I Kopaenko
- Medical Academy named after S.I. Georgievsky of Vernadsky CFU, 5/7 Lenin Avenue, Simferopol, Republic of Crimea, Russian Federation, 295051
| | - N V Ivanova
- Medical Academy named after S.I. Georgievsky of Vernadsky CFU, 5/7 Lenin Avenue, Simferopol, Republic of Crimea, Russian Federation, 295051
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Ziaei M, Vellara H, Gokul A, Patel D, McGhee CNJ. Prospective 2-year study of accelerated pulsed transepithelial corneal crosslinking outcomes for Keratoconus. Eye (Lond) 2019; 33:1897-1903. [PMID: 31273313 DOI: 10.1038/s41433-019-0502-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 01/27/2019] [Accepted: 04/24/2019] [Indexed: 01/17/2023] Open
Abstract
AIMS To report 2-year outcomes of transepithelial, accelerated, pulsed, corneal crosslinking (t-ACXL) for patients with progressive keratoconus. METHODS Prospective, interventional case series at a university hospital tertiary referral centre. Forty eyes with progressive keratoconus undergoing t-ACXL were included. Treatment was performed with pulsed illumination (1 s on/1 s off) using 45 mW/cm2 for 5 min and 20 s, for a surface dose of 7.2 J cm2. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), corneal tomography, anterior segment optical coherence tomography (OCT) and confocal microscopy were evaluated preoperatively and at 12 and 24 months postoperatively. RESULTS The mean patient age was 23.32 ± 5.18 years (SD) (range 14-42 years). The mean CDVA significantly improved from 0.38 ± 0.32 logMAR at baseline to 0.30 ± 0.21 logMAR at 24 months (P < 0.01). There was no significant difference in UDVA, MRSE, asymmetry indices, tomographic parameters and endothelial density. The improvement in visual acuity was inversely correlated with preoperative CDVA and preoperative KMax. No complications were encountered. CONCLUSIONS In this prospective study, t-ACXL appeared safe and effective in halting progression of keratoconus within a follow-up period of 24 months.
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Affiliation(s)
- Mohammed Ziaei
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
| | - Hans Vellara
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Akilesh Gokul
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Dipika Patel
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - Charles N J McGhee
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
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Madeira C, Vasques A, Beato J, Godinho G, Torrão L, Falcão M, Falcão-Reis F, Pinheiro-Costa J. Transepithelial accelerated versus conventional corneal collagen crosslinking in patients with keratoconus: a comparative study. Clin Ophthalmol 2019; 13:445-452. [PMID: 30880905 PMCID: PMC6402612 DOI: 10.2147/opth.s189183] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose To systematically compare the efficacy of transepithelial accelerated corneal collagen crosslinking (TE-ACXL) with conventional corneal collagen crosslinking (C-CXL) in patients with progressive keratoconus. Methods Eyes of patients with progressive keratoconus who were treated with C-CXL (3 mW/cm2 for 30 minutes) were compared with those who underwent TE-ACXL (6 mW/cm2 for 15 minutes). Best-corrected visual acuity (BCVA), keratometry values, corneal thickness, and topometric indexes were compared before CXL, and at 2 months, 6 months, and 12 months postoperatively. Results The study enrolled 26 eyes of which 16 had TE-ACXL and 10 had C-CXL. Both groups were comparable at baseline and 12 months in terms of BCVA (P=0.16 and P=0.57), Kmax (maximum keratometry) (P=0.31 and P=0.73), pachymetry (P=0.75 and P=0.37), index of surface variance (ISV) (P=0.45 and P=0.86), index of vertical asymmetry (IVA) (P=0.26 and P=0.61), and index of height decentration (IHD) (P=0.27 and P=0.86, respectively). We did not observe significant differences between preoperative and 12-month postoperative readings in within-group analysis: ΔKmax (TE-ACXL, −2.13±5.41, P=0.25 vs C-CXL, 0.78±1.65, P=0.17), Δpachymetry (TE-ACXL, 4.10±14.83, P=0.41 vs C-CXL, −8.90±22.09, P=0.24), ΔISV (TE-ACXL, −8.50±21.26, P=0.24 vs C-CXL, 3.80±12.43, P=0.36), ΔIVA (TE-ACXL, −0.12±0.31, P=0.26 vs C-CXL, 0.03±0.18, P=0.61), and ΔIHD (TE-ACXL, −0.03±0.07, P=0.18 vs C-CXL, −0.01±0.03, P=0.88). Conclusion Both TE-ACXL and C-CXL were similarly effective. Further follow-up is required to determine whether these techniques are comparable in the long-term.
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Affiliation(s)
- Carolina Madeira
- Department of Ophthalmology, Centro Hospitalar de São João, Porto, Portugal,
| | - Ana Vasques
- Faculty of Medicine, University of Porto, Porto, Portugal
| | - João Beato
- Department of Ophthalmology, Centro Hospitalar de São João, Porto, Portugal,
| | - Gonçalo Godinho
- Department of Ophthalmology, Centro Hospitalar de São João, Porto, Portugal,
| | - Luís Torrão
- Department of Ophthalmology, Centro Hospitalar de São João, Porto, Portugal,
| | - Manuel Falcão
- Department of Ophthalmology, Centro Hospitalar de São João, Porto, Portugal, .,Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Fernando Falcão-Reis
- Department of Ophthalmology, Centro Hospitalar de São João, Porto, Portugal, .,Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - João Pinheiro-Costa
- Department of Ophthalmology, Centro Hospitalar de São João, Porto, Portugal, .,Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal
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Correlation of Demarcation Line Depth With Medium-Term Efficacy of Different Corneal Collagen Cross-Linking Protocols in Keratoconus. Cornea 2018; 37:1511-1516. [PMID: 30157054 DOI: 10.1097/ico.0000000000001733] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare demarcation line depth (DD) and topographic changes among different corneal collagen cross-linking (CXL) protocols and to evaluate the relation of DD with medium-term efficacy of CXL in halting progression of keratoconus. METHODS The study included 124 patients (mean age 19 ± 4.8 years) with progressive keratoconus who underwent conventional (3 mW/cm/30 min), accelerated (18 mW/cm/5 min), or transepithelial (TE) CXL (3 mW/cm/30 min) and followed up for at least 2 years. Baseline and final corneal topographic parameters and DD determined with anterior segment optical coherence tomography 1 month after CXL were compared among the protocols and the correlation between DD and topographic changes at the end of 24 months was analyzed. P < 0.05 was considered as statistically significant. RESULTS Mean DD was significantly higher in the conventional and accelerated groups (335.19 ± 71.13 μm and 304.97 ± 94.45 μm, respectively) compared with the TE group (239.92 ± 71.37 μm) (P < 0.001). After conventional and TE CXL, keratometric parameters improved remarkably, whereas accelerated CXL only lowered K1 and Kmax (P < 0.05). No correlation was found between DD and topographic changes (P > 0.05). Progression was detected in 3 eyes in the conventional group (4.1%), 3 in the accelerated group (7.7%), and none in the TE group. The use of either riboflavin D or M made no differences in terms of DD and topographic parameters (P > 0.05). CONCLUSIONS In conventional and accelerated protocols, corneal stromal demarcation line is deeper compared with TE CXL; however, the DD has no correlation with topographic changes, which means that DD is not a direct measure for the efficacy of CXL.
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30
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Transepithelial versus epithelium-off corneal crosslinking for corneal ectasia. J Cataract Refract Surg 2018; 44:1507-1516. [PMID: 30314751 DOI: 10.1016/j.jcrs.2018.08.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/14/2018] [Accepted: 08/19/2018] [Indexed: 01/24/2023]
Abstract
This review compared the clinical results of transepithelial corneal crosslinking (CXL) to epithelium-off (epi-off) CXL in progressive corneal ectasia using a metaanalysis. The Cochrane databases and Medline were searched for randomized controlled trials (RCTs). Seven RCTs involving 505 eyes that met the eligibility criteria were identified. The epi-off CXL group showed significantly better outcomes in postoperative changes in maximum keratometry (K) during 1-year observation periods. Transepithelial CXL resulted in significantly greater post-treatment central corneal thickness and best spectacle-corrected visual acuity (BSCVA). The presence of a postoperative demarcation line was significantly more frequent after epi-off CXL than that after transepithelial CXL. No statistically significant difference was found between other parameters. Although patients in the transepithelial CXL group demonstrated a greater improvement in BSCVA compared with patients in the epi-off CXL group at the 1 year follow-up, transepithelial CXL had less impact on halting progressive corneal ectasia in terms of maximum K than epi-off CXL.
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31
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Chen S, Chan TCY, Zhang J, Ding P, Chan JCK, Yu MCY, Li Y, Jhanji V, Wang Q. Epithelium-on corneal collagen crosslinking for management of advanced keratoconus. J Cataract Refract Surg 2018; 42:738-49. [PMID: 27255251 DOI: 10.1016/j.jcrs.2016.02.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 01/29/2016] [Accepted: 02/01/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE To report the 1-year visual and keratometric results of epithelium-on corneal collagen crosslinking (CXL) for advanced keratoconus (median maximum keratometry [K] ≥58.0 diopters [D]). SETTING School of Ophthalmology and Optometry and Eye Hospital of Wenzhou Medical College, Wenzhou, China. DESIGN Prospective case series. METHODS Patients with bilateral progressive keratoconus had tetracaine-enhanced epithelium-on CXL. The worse eye had CXL, and the fellow eye was not treated. Results were reported 1, 3, 6, and 12 months postoperatively. The outcomes were compared with those in the fellow untreated eyes. RESULTS Twenty-one eyes of 21 patients with a median age of 20.4 years (interquartile range [IQR], 9.5 years) were treated. A significant improvement in postoperative uncorrected distance visual acuity was observed at 12 months (P = .002). Postoperative corrected distance visual acuity improved at 6 months and 12 months (P ≤ .009) compared with baseline values. The maximum K decreased by 1.63 D from the median preoperative maximum K of 62.7 D (IQR, 12.9 D) at 12 months (P < .001). The reduction in maximum K was higher after CXL than in untreated eyes at the end of 12 months (P = .001). Correlation analysis between the preoperative maximum K values and the change over 6 to 12 months between different studies showed a significant correlation (r = -0.764, P < .001; Spearman correlation). CONCLUSIONS Epithelium-on CXL was an effective treatment for patients with advanced keratoconus. A higher preoperative maximum K value correlated with greater corneal flattening after CXL. FINANCIAL DISCLOSURE None of the authors has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Shihao Chen
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
| | - Tommy C Y Chan
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
| | - Jia Zhang
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
| | - Ping Ding
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
| | - Jason C K Chan
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
| | - Marco C Y Yu
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
| | - Yini Li
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
| | - Vishal Jhanji
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China.
| | - Qinmei Wang
- From the Department of Ophthalmology (Chen, Zhang, Ding, Li, Wang), Affiliated Eye Hospital of Wenzhou Medical College, Wenzhou, Zhejiang, the Department of Ophthalmology and Visual Sciences (T.C.Y. Chan, Jhanji), Chinese University of Hong Kong, and Hong Kong Eye Hospital (T.C.Y. Chan, J.C.K. Chan, Jhanji), Mongkok, Kowloon, and the Department of Mathematics and Statistics (Yu), Hang Seng Management College, Hong Kong, China
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Atia R, Jouve L, Sandali O, Laroche L, Borderie V, Bouheraoua N. Early Epithelial Remodeling After Standard and Iontophoresis-Assisted Corneal Cross-linking as Evaluated by Spectral-Domain Optical Coherence Tomography. J Refract Surg 2018; 34:551-558. [DOI: 10.3928/1081597x-20180702-01] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/18/2018] [Indexed: 11/20/2022]
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Comparison of Epithelium-Off Versus Transepithelial Corneal Collagen Cross-Linking for Keratoconus: A Systematic Review and Meta-Analysis. Cornea 2018; 37:1018-1024. [PMID: 29847492 DOI: 10.1097/ico.0000000000001632] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE To systematically compare standard epithelium-off corneal collagen cross-linking (SCXL) and transepithelial corneal collagen cross-linking (TECXL) for treating keratoconus. METHODS PubMed, EMBASE, the Cochrane Library, the US trial registry (ClinicalTrials.gov), VIP Database, Wanfang Databse, and China National Knowledge Infrastructure searches up to February 2017 were conducted. Primary outcomes were changes at 1 year in uncorrected distance visual acuity, maximum keratometry (Kmax), and mean keratometry (mean K). Secondary outcomes were changes at 1 year in corrected distance visual acuity, mean refractive spherical equivalent, central corneal thickness, endothelial cell density, and the occurrence of adverse events. RESULTS Eight studies with a total of 455 eyes were included. For primary outcomes, SCXL showed a greater reduction in mean K [standardized mean difference (SMD) 0.28; 95% confidence interval (CI), 0.03-0.53; P = 0.03] compared with TECXL. Subgroup analysis indicated that SCXL had a comparable effect on reducing mean K with TECXL protocols using chemical enhancers (SMD 0.05; 95% CI, -0.36 to 0.45; P = 0.82) but a greater reduction in mean K compared with TECXL with current iontophoretic protocols (SMD 0.43; 95% CI, 0.10-0.75; P = 0.01). For the other outcomes, there were no statistically significant differences. CONCLUSIONS With the exception of less reduction in mean K with current iontophoretic protocols, analysis of the limited number of comparative studies available seems to demonstrate that SCXL and TECXL have a comparable effect on visual, refractive, pachymetric, and endothelial parameters at 1 year after surgery. Further follow-up is required to determine whether these techniques are comparable in the long-term.
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Development of a Reference Model for Keratoconus Progression Prediction Based on Characterization of the Course of Nonsurgically Treated Cases. Cornea 2018; 37:1497-1505. [DOI: 10.1097/ico.0000000000001673] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Zhang X, Zhao J, Li M, Tian M, Shen Y, Zhou X. Conventional and transepithelial corneal cross-linking for patients with keratoconus. PLoS One 2018; 13:e0195105. [PMID: 29621306 PMCID: PMC5886478 DOI: 10.1371/journal.pone.0195105] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 03/17/2018] [Indexed: 11/19/2022] Open
Abstract
Previous studies investigating the effectiveness of conventional corneal collagen cross-linking (CXL) and transepithelial CXL in keratoconus treatment have reported conflicting outcomes. Therefore, we conducted a meta-analysis to compare the effectiveness of these treatments. We searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials for prospective randomized controlled trials (RCTs) with no restrictions. We included visual acuity (corrected distance visual acuity, uncorrected distance visual acuity) and corneal keratometry (K) as primary outcome parameters, and spherical equivalent, central corneal thickness (CCT), and endothelial cell density, as secondary parameters. We finally included seven reports (including six RCTs involving 305 participants and 344 eyes). Our analysis revealed significant postoperative differences in average K and CCT values between conventional and transepithelial CXL-treated patients [K: weighted mean difference (WMD) = 0.79, 95% confidence interval (CI) = 0.04-1.53, p = 0.04; CCT: WMD = 4.53, 95% CI = 0.42-8.64, p = 0.03]. In contrast, we did not find any significant differences in visual acuity, flattest K value, steepest K value, cylinder K value, apex K value, spherical equivalent, or endothelial cell density between groups. In conclusion, transepithelial CXL has a more protective influence on corneal thickness than conventional CXL, and results in lesser postoperative corneal flattening. Further investigation of the clinical outcomes of transepithelial CXL is required.
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Affiliation(s)
- Xiaoyu Zhang
- Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Jing Zhao
- Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Meiyan Li
- Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Mi Tian
- Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Yang Shen
- Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
| | - Xingtao Zhou
- Eye and ENT Hospital of Fudan University, Myopia Key Laboratory of the Health Ministry, Shanghai, China
- * E-mail:
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Ayar O, Muftuoglu O, Akdemir MO, Ozmen MC. Results of ethanol-assisted epithelium-on corneal cross-linking with and without intrastromal corneal ring implantation. Int Ophthalmol 2018; 39:651-659. [PMID: 29429144 DOI: 10.1007/s10792-018-0858-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 02/03/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the topographic, refractive, and pachymetric changes after ethanol-assisted transepithelial corneal cross-linking (CXL) to stabilize progression of keratoconus (KC). PATIENTS AND METHODS This study retrospectively evaluated the long-term topographic, refractive, and pachymetric changes in patients diagnosed with KC who underwent corneal cross-linking and/or intrastromal corneal ring segment (ICRS) implantation. The subjects were divided into three groups, corresponding to eyes treated with CXL alone (group 1), CXL and ICRS at the same time (group 2), and CXL after ICRS implantation (group 3). Corrected visual acuity and refraction, steep keratometry (SteepK) values, steepest keratometry reading on sagittal curvature map, and corneal thickness were recorded preoperatively and at each visit. Changes between measurements were assessed during follow-up. RESULTS Corrected distant visual acuity (CDVA) values improved in all groups compared with baseline, but the differences were not statistically significant except for the first year (p > 0.05). In groups 1 and 3, SteepK values did not change statistically significantly during the entire follow-up (p > 0.05). In group 2, SteepK values statistically significantly decreased at all follow-up examinations compared with baseline, determined as the first month after ICRS implantation (p < 0.05). Complication rates were acceptable without any need for surgical intervention. CONCLUSIONS Single-session ethanol-assisted transepithelial CXL with or without ICRS implantation was a safe and effective procedure to halt progression of KC.
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Affiliation(s)
- Orhan Ayar
- Department of Ophthalmology, Faculty of Medicine, Bülent Ecevit University, 67600, Esenköy, Kozlu, Zonguldak, Turkey.
| | - Orkun Muftuoglu
- Department of Ophthalmology, Faculty of Medicine, Koç University, Istanbul, Turkey
| | - Mehmet Orcun Akdemir
- Department of Ophthalmology, Faculty of Medicine, Bülent Ecevit University, 67600, Esenköy, Kozlu, Zonguldak, Turkey
| | - Mehmet Cuneyt Ozmen
- Department of Ophthalmology, Faculty of Medicine, Gazi University, Ankara, Turkey
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Huang T, Ye R, Ouyang C, Hou C, Hu Y, Wu Q. Use of Donors Predisposed by Corneal Collagen Cross-linking in Penetrating Keratoplasty for Treating Patients With Keratoconus. Am J Ophthalmol 2017; 184:115-120. [PMID: 29032110 DOI: 10.1016/j.ajo.2017.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate whether use of donors predisposed by corneal collagen cross-linking (CXL) reduced myopic refractive errors for keratoconic eyes after penetrating keratoplasty (PK). DESIGN Randomized controlled trial. METHODS One hundred sixteen eyes of 116 patients with keratoconus from Zhongshan Ophthalmic Center were enrolled. Using stratified block randomization, we assigned eligible eyes to the CXL graft group (Group 1) or conventional graft group (Group 2). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), and topographic data were compared 12, 24, and 36 months after surgery. RESULTS Group 1 had better UDVA and CDVA than Group 2 after 1 year follow-up. Also, Group 1 had a lesser degree of SE and lower manifest cylinder than Group 2. At 3 years follow-up, mean CDVA was 0.17 ± 0.10 logarithm of the minimum angle of resolution (logMAR) in Group 1 vs 0.23 ± 0.12 logMAR in Group 2 (P = .004). Mean SE was -3.50 ± 2.93 diopter (D) in Group 1 and -4.02 ± 2.57 D in Group 2 (P = .034). Mean manifest cylinder was -5.22 ± 2.64 D and -6.35 ± 2.80 D in Group 1 and Group 2, respectively (P = .013). At 3 years follow-up, simulated keratometry in the steepest meridian (Kmax) was 46.85 ± 2.85 D vs 49.37 ± 2.92 D (P = .036); corneal power was 44.41 ± 2.89 D vs 46.35 ± 2.87 D (P = .001); and keratometric astigmatism was 4.53 ± 1.06 D vs 5.98 ± 1.28 D (P < .001) in Group 1 and Group 2, respectively. CONCLUSIONS Use of donors predisposed by CXL could reduce topographic readings after PK for the treatment of keratoconus, and consequently reduce myopic refractive errors and improve visual acuity.
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Liu Y, Liu Y, Zhang YN, Li AP, Zhang J, Liang QF, Jie Y, Pan ZQ. Systematic review and Meta-analysis comparing modified cross-linking and standard cross-linking for progressive keratoconus. Int J Ophthalmol 2017; 10:1419-1429. [PMID: 28944203 DOI: 10.18240/ijo.2017.09.15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 06/26/2017] [Indexed: 11/23/2022] Open
Abstract
AIM To compare the effectiveness and safety between modified cross-linking (MC) and standard cross-linking (SC) in mild or moderate progressive keratoconus. METHODS Eligible studies were retrieved from four electronic databases, including CENTRAL, Clinical Trials gov, PupMed and OVID MEDLINE. We set post-surgical maximum K value (Kmax) as the primary outcome. In addition, uncorrected and corrected distant visual acuity (UDVA and UDVA), spherical equivalent (SE), endothelial cell density (ECD), central cornea thickness (CCT) and depth of demarcation line (DDL) were Meta-analyzed as secondary outcomes. Mean differences for these outcomes were pooled through either a random-effect model or fixed-effect model according to data heterogeneity. RESULTS Twenty-four comparative studies either on accelerated cross-linking (AC) compared with SC or on trans-epithelial cross-linking (TC) compared with SC were included and pooled for analysis. The results indicated that MC was significantly inferior to SC at delaying Kmax deterioration [AC vs SC 0.49 (95% CI: 0.04-0.94, I2=75%, P=0.03); TC vs SC 1.15 (95% CI: 0.54-1.75, I2=50%, P=0.0002)]. SE decreased significantly for SC when compared to AC [0.62 (95% CI: 0.38-0.86, I2=22%, P<0.00001)]. DDL of SC was more significantly deeper than that of TC [-133.49 (95% CI: -145.94 to -121.04, I2=33%, P<0.00001)]. Other outcomes demonstrated comparable results between MC and SC. CONCLUSION SC is more favorable at halting the progression of keratoconus, but visual acuity improvement showed comparable results between MCs and SC.
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Affiliation(s)
- Yang Liu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100005, China
| | - Yi Liu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100005, China
| | - Ying-Nan Zhang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100005, China
| | - Ai-Peng Li
- Department of Ophthalmology, First Hospital of Jilin University, Changchun 130021, Jilin Province, China
| | - Jing Zhang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100005, China
| | - Qing-Feng Liang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100005, China
| | - Ying Jie
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100005, China
| | - Zhi-Qiang Pan
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing 100005, China
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Updates on corneal collagen cross-linking: Indications, techniques and clinical outcomes. J Curr Ophthalmol 2017; 29:235-247. [PMID: 29270469 PMCID: PMC5735256 DOI: 10.1016/j.joco.2017.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 07/18/2017] [Accepted: 07/22/2017] [Indexed: 12/17/2022] Open
Abstract
Purpose To review the historical background and basic principles of collagen cross-linking, to bring together the data regarding the outcomes and complications of collagen cross-linking and finally to explore the efficacy and safety of new variations of this technique. Methods A literature review was performed using PubMed and Scopus. The following keywords were used for literature search: cross linking, crosslinking, cross-linking, keratoconus, keratectasia. Results In contrast to traditional treatment modalities for keratoconus (KCN), this new technique addresses the progression of the disease. Several clinical studies have been conducted to assess the efficacy of corneal collagen cross-linking (CXL) in the last decade. The results were promising as collagen cross-linking showed significant improvement in visual acuity and keratometric values. Moreover, initial results show that it is a safe procedure with few reported complications. Conclusion CXL is an emerging treatment method in ophthalmology that offers the possibility to effectively treat progressive KCN.
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Koc M, Bostanci B, Demirel OO, Genc F, Tekin K, Koban Y, Dincel AS, Sen M, Yilmazbas P. The Effect of Ascorbic Acid (Vitamin C) on Transepithelial Corneal Cross-Linking in Rabbits. J Ocul Pharmacol Ther 2017; 33:525-529. [PMID: 28590790 DOI: 10.1089/jop.2017.0025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Mustafa Koc
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Basak Bostanci
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Ozlem Ozbas Demirel
- Department of Biochemistry, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Feyza Genc
- Department of Chemistry, Hacettepe University, Ankara, Turkey
| | - Kemal Tekin
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Yaran Koban
- Department of Ophthalmology, FEBO, Kafkas University, Kars, Turkey
| | | | - Murat Sen
- Department of Chemistry, Hacettepe University, Ankara, Turkey
| | - Pelin Yilmazbas
- Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
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Akbar B, Intisar-Ul-Haq R, Ishaq M, Arzoo S, Siddique K. Transepithelial corneal crosslinking in treatment of progressive keratoconus: 12 months' clinical results. Pak J Med Sci 2017; 33:570-575. [PMID: 28811773 PMCID: PMC5510105 DOI: 10.12669/pjms.333.11907] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE The purpose of this study was to evaluate the safety and efficacy of transepithelial corneal collagen cross linking (TE-CXL) with modified riboflavin and accelerated UVA irradiance in thin corneas with pachymetry less than 400 microns at thinnest point, untreatable by epithelium off corneal collagen cross linking (CXL) in adult Pakistani population with progressive keratoconus. METHODS This quasi experimental study included twenty six eyes of 26 patients with progressive keratoconus who underwent accelerated transepithelial CXL in Armed forced institute of ophthalmology with 12 months follow up. Modified riboflavin, ParaCel ((riboflavin 0.25%, Benzalkonium chloride, EDTA, Trometamol, hydroxypropyl methylcellulose) and vibeX Xtra (riboflavin 0.25%) (Avedro, USA)) were applied to cornea in two stages. Uncorrected and Corrected Distant Visual Acuities (UDVA, CDVA), spherical equivalent (SE), astigmatism, pachymetry at thinnest point (Pachy thin), apex keratometry (Kmax), simulated and steep keratometry (Sim K, steep K) were measured at baseline and at 3, 6 and 12 months post operatively. The cornea was then exposed to accelerated UVA irradiance of 9mW/cm2 for 10 min (total dose 30 mW/cm2). RESULTS The mean age of the patient was 24.54±5.16 years. UDVA, CDVA, SE, astigmatism significantly improved at all postoperative test points (p=0.000, 0.004, 0.000, 0.004 respectively). Kmax and pachy thin were significantly reduced over baseline at 1 year (p=0.000, 0.004 respectively). Topographic indices Sim K and steep K did not show significant changes. No intra or post-operative complications were reported. CONCLUSION Transepithelial accelerated CXL with modified riboflavin is a safe and effective procedure which halt disease progression in thin corneas with progressive keratoconus.
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Affiliation(s)
- Bushra Akbar
- Dr. Bushra Akbar, MBBS. Department of Ophthalmology, Armed Forces Institute of Ophthalmology, AFIO, Rawalpindi, Pakistan
| | - Rana Intisar-Ul-Haq
- Dr. Rana Intisar ul Haq, MBBS, DO, MCPS, FCPS. Department of Ophthalmology, Armed Forces Institute of Ophthalmology, AFIO, Rawalpindi, Pakistan
| | - Mazhar Ishaq
- Dr. Mazhar Ishaq, MBBS, FRCS Ed, FRCOPHTH, FCPS. Department of Ophthalmology, Armed Forces Institute of Ophthalmology, AFIO, Rawalpindi, Pakistan
| | - Sabahat Arzoo
- Sabahat Arzoo, BSC (Hons.) Optometry, Orthoptics. Department of Ophthalmology, Armed Forces Institute of Ophthalmology, AFIO, Rawalpindi, Pakistan
| | - Kashif Siddique
- Kashif Siddique, M.Sc (Biostatistics). King Salman Armed Forces Hospital, Tabuk, KSA Academic Affairs (Research Unit), Saudi Arabia
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Lombardo M, Giannini D, Lombardo G, Serrao S. Randomized Controlled Trial Comparing Transepithelial Corneal Cross-linking Using Iontophoresis with the Dresden Protocol in Progressive Keratoconus. Ophthalmology 2017; 124:804-812. [PMID: 28283279 DOI: 10.1016/j.ophtha.2017.01.040] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 10/20/2022] Open
Abstract
PURPOSE To compare clinical outcomes of transepithelial corneal cross-linking using iontophoresis (T-ionto CL) and standard corneal cross-linking (standard CL) for the treatment of progressive keratoconus 12 months after the operation. DESIGN Prospective randomized controlled clinical trial. PARTICIPANTS Thirty-four eyes of 25 participants with progressive keratoconus were randomized into T-ionto CL (22 eyes) or standard CL (12 eyes). METHODS T-ionto CL was performed using an iontophoresis device with dextran-free 0.1% riboflavin-5-phosphate solution with enhancers and by irradiating the cornea with a 10 mW/cm2 ultraviolet A device for 9 minutes. Standard CL was performed according to the Dresden protocol. MAIN OUTCOME MEASURES The primary outcome measure was stabilization of keratoconus after 12 months through analysis of maximum simulated keratometry readings (Kmax, diopters). Other outcome measures were corrected distance visual acuity (CDVA, logarithm of the minimum angle of resolution [logMAR]), manifest spherical equivalent refraction (D), central corneal thickness (CCT, micrometers) and endothelial cell density (ECD). Follow-up examinations were arranged at 3 and 7 days and 1, 3, 6, and 12 months. RESULTS Twelve months after T-ionto CL and standard CL, Kmax on average flattened by -0.52±1.30 D (P = 0.06) and -0.82±1.20 D (P = 0.04), respectively. The mean change in CDVA was -0.10±0.12 logMAR (P = 0.003) and -0.03±0.06 logMAR (P = 0.10) after T-ionto CL and standard CL, respectively. The manifest spherical equivalent refraction changed on average by +0.71±1.44 D (P = 0.03) and +0.21±0.76 D (P = 0.38), respectively. The CCT and ECD measures did not change significantly in any group at 12 months. Significant differences in the outcome measures between treatments were found in the first week postoperatively. No complications occurred in the T-ionto CL group; 1 eye (8%) had sterile corneal infiltrates, which did not affect the final visual acuity, in the standard CL group. CONCLUSIONS Significant visual and refractive improvements were found 12 months after T-ionto CL, though the average improvement in corneal topography readings was slightly lower than the Dresden protocol in the same period.
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Affiliation(s)
| | | | - Giuseppe Lombardo
- Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici, Messina, Italy; Vision Engineering Italy srl, Rome, Italy
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Evaluation of Iontophoretic Collagen Cross-linking for Early Stage of Progressive Keratoconus Compared to Standard Cross-linking: A Non-Inferiority Study. Ophthalmol Ther 2017; 6:147-160. [PMID: 28160249 PMCID: PMC5449295 DOI: 10.1007/s40123-017-0076-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Indexed: 11/29/2022] Open
Abstract
Introduction The purpose of this study was to evaluate the efficacy and safety of iontophoretic collagen cross-linking (I-CXL) compared to epithelium-off standard collagen cross-linking (CXL) in treating the early stages of progressive keratoconus. Methods This retrospective cohort study at Oftaprof Clinic, Iasi, Romania included 40 eyes of 40 patients with progressive keratoconus stage I according to the Amsler classification who underwent I-CXL and the results were compared with a matched group of 40 eyes from 40 patients who received standard CXL. The follow-up period was 24 months. Uncorrected (UCVA) and corrected (CDVA) distance visual acuities, corneal topography, and pachymetry were evaluated in all patients. Results The mean patient age was 26.52 ± 3.77 years for the standard CXL group and 28.32 ± 4.91 for the I-CXL group. The mean UCVA and CDVA improved significantly in both groups. At 12 months, the improvement of UCVA was greater in the I-CXL group (P < 0.05). There was a statistically significant different trend in CDVA between groups with a more favorable outcome for the standard CXL group (P < 0.01). The manifest cylinder decreased by a mean of 0.962 ± 0.114 D in the epithelium-off CXL group and by 0.831 ± 0.082 D in the I-CXL group (P < 0.001). At 24 months, the Kmax values improved by 1.2 ± 0.199 D in the standard group and by 0.908 ± 0.177 D in the I-CXL group (P < 0.001). Conclusion All parameters either improved or remained unchanged after the iontophoretic collagen cross-linking intervention. I-CXL was found to be as effective as the standard technique. Electronic supplementary material The online version of this article (doi:10.1007/s40123-017-0076-8) contains supplementary material, which is available to authorized users.
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Akbar B, Intisar-Ul-Haq R, Ishaq M, Fawad A, Arzoo S, Siddique K. Comparison of transepithelial corneal crosslinking with epithelium-off crosslinking (epithelium-off CXL) in adult Pakistani population with progressive keratoconus. Taiwan J Ophthalmol 2017; 7:185-190. [PMID: 29296550 PMCID: PMC5747228 DOI: 10.4103/tjo.tjo_38_17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE: The purpose of this study is to compare the safety and efficacy of transepithelial corneal crosslinking (CXL) with epithelium-off crosslinking (epithelium-off CXL) in the treatment of progressive keratoconus in adult Pakistani population. MATERIALS AND METHODS: Sixty-four eyes of 64 consecutive patients of progressive keratoconus were included in this quasi-experimental study. Thirty-two eyes received transepithelial CXL with Peschke TE (0.25% riboflavin (Vitamin B2), 1.2% hydroxypropyl methylcellulose (HPMC), 0.01% benzalkonium chloride) and 32 eyes received epithelium-off CXL with Peschke M (0.1% riboflavin (Vitamin B2) 0.1%, HPMC 1.1%.) The cornea was then exposed to ultraviolet A light at an irradiance of 3 mW/cm2 for 30 min. The primary outcome measure, clinical stabilization of keratoconus was defined as an increase of no more than 1D in Kmax at 1 year. Other parameters evaluated at baseline and 3, 6, 12, and 18 months postoperatively were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), astigmatism (Ast), simulated keratometry, steep keratmetry (steep K), and corneal thickness at thinnest point (pachy thin). RESULTS: Both epithelium-off CXL and transepithelial CXL groups showed a significant reduction in Kmax, steep K, simulated K, corneal pachymetry at all test points (P < 0.05) with significantly greater reductions achieved in epithelium-off CXL group at 18 months follow-up. The mean UDVA, CDVA, SE, Ast significantly improved in both groups (P < 0.05). The mean postoperative UDVA and CDVA between the groups were not significant at 12 months (P = 0.650, 0.018, respectively). Clinical stabilization was achieved in 94% of eyes in epithelium-off CXL and 75% of eyes in transepithelial CXL. In epithelium-off CXL, three eyes exhibited stromal haze resolved by corticosteroid treatment. No complication was documented in transepithelial CXL group. CONCLUSION: Transepithelial CXL is not recommended to be replaced completely by standard epithelium-off CXL due to continued ectatic progression in 25% of cases. However, thin corneas, unfit for standard epithelium-off CXL, can benefit from transepithelial CXL.
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Affiliation(s)
- Bushra Akbar
- Department of Ophthalmology, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan
| | - Rana Intisar-Ul-Haq
- Department of Ophthalmology, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan
| | - Mazhar Ishaq
- Department of Ophthalmology, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan
| | - Ayesha Fawad
- Department of Ophthalmology, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan
| | - Sabahat Arzoo
- Department of Ophthalmology, Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan
| | - Kashif Siddique
- Biostatistics, King Salman Armed Forces Hospital, Tabuk, KSA Academic Affairs (Research Unit), Saudi Arabia
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Ünlü M, Yüksel E, Bilgihan K. Effect of corneal cross-linking on contact lens tolerance in keratoconus. Clin Exp Optom 2016; 100:369-374. [PMID: 27654998 DOI: 10.1111/cxo.12470] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/16/2016] [Accepted: 06/09/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The aim was to investigate changes in corneal sensation and rigid gas-permeable (RGP) contact lens tolerance after corneal cross-linking (CXL) on patients with keratoconus. METHODS Thirty eyes of 30 patients, who were RGP lens intolerant, were treated with CXL. The main outcome measures were corneal sensation evaluation by Cochet-Bonnet esthesiometry, sub-basal nerve fibre assessment by corneal in vivo confocal microscopy and RGP contact lens tolerance evaluation with the Likert scale and wearing time. All eyes were evaluated preoperatively and post-operatively at one, three and six months after CXL procedure. RESULTS The mean age was 25.3 ± 6.2 years. Preoperatively, the maximum keratometry (Kmax) in study eyes was 56.89 ± 4.60 D. Six months after CXL, it reduced to 56.03 ± 4.85 D (p = 0.01). Preoperative mean corneal sensation was 0.44 ± 0.05 g/mm2 , (range: 0.40 to 0.55); it was significantly decreased at the first month and increased to preoperative values after six months. The sub-basal nerve plexus could not be visualised in 90 per cent of the patients by confocal microscopy at one month post-operatively. Gradual restoration of corneal innervation with almost similar preoperative levels at post-operative month six was noted. There were significant differences in Likert scores between preoperative and third and sixth months after CXL. Likert scale scores correlated significantly with corneal sensitivity. CONCLUSION It can be concluded that increased RGP contact lens tolerance after CXL may be associated with the potential role of decreased corneal sensitivity and corneal flattening after CXL.
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Affiliation(s)
- Metin Ünlü
- Ophthalmology Department, School of Medicine, Erciyes University, Kayseri, Turkey
| | - Erdem Yüksel
- Ophthalmology Department, School of Medicine, Gazi University, Ankara, Turkey
| | - Kamil Bilgihan
- Ophthalmology Department, School of Medicine, Gazi University, Ankara, Turkey
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Lombardo M, Serrao S, Raffa P, Rosati M, Lombardo G. Novel Technique of Transepithelial Corneal Cross-Linking Using Iontophoresis in Progressive Keratoconus. J Ophthalmol 2016; 2016:7472542. [PMID: 27597895 PMCID: PMC5002487 DOI: 10.1155/2016/7472542] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 07/14/2016] [Indexed: 11/17/2022] Open
Abstract
In this work, the authors presented the techniques and the preliminary results at 6 months of a randomized controlled trial (NCT02117999) comparing a novel transepithelial corneal cross-linking protocol using iontophoresis with the Dresden protocol for the treatment of progressive keratoconus. At 6 months, there was a significant average improvement with an average flattening of the maximum simulated keratometry reading of 0.72 ± 1.20 D (P = 0.01); in addition, corrected distance visual acuity improved significantly (P = 0.08) and spherical equivalent refraction was significantly less myopic (P = 0.02) 6 months after transepithelial corneal cross-linking with iontophoresis. The novel protocol using iontophoresis showed comparable results with standard corneal cross-linking to halt progression of keratoconus during 6-month follow-up. Investigation of the long-term RCT outcomes are ongoing to verify the efficacy of this transepithelial corneal cross-linking protocol and to determine if it may be comparable with standard corneal cross-linking in the management of progressive keratoconus.
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Affiliation(s)
- Marco Lombardo
- Fondazione G.B. Bietti, IRCCS, Via Livenza 3, 00198 Roma, Italy
| | | | - Paolo Raffa
- Dipartimento di Medicina Molecolare, Università di Padova, Via A. Gabelli 63, 35121 Padova, Italy
| | - Marianna Rosati
- Fondazione G.B. Bietti, IRCCS, Via Livenza 3, 00198 Roma, Italy
| | - Giuseppe Lombardo
- Consiglio Nazionale delle Ricerche, Istituto per i Processi Chimico-Fisici, Viale Stagno d'Alcontres 37, 98158 Messina, Italy
- Vision Engineering Italy srl, Via Adda 7, 00198 Rome, Italy
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Kır MB, Türkyılmaz K, Öner V. Transepithelial High-Intensity Cross-Linking for the Treatment of Progressive Keratoconus: 2-year Outcomes. Curr Eye Res 2016; 42:28-31. [PMID: 27249007 DOI: 10.3109/02713683.2016.1148742] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE To report 2-year outcomes of transepithelial high-intensity cross-linking (CXL) procedure in the treatment of patients with progressive keratoconus. METHODS Forty-eight eyes of 48 consecutive progressive keratoconus patients who underwent transepithelial accelerated CXL procedure were enrolled in the study. Each patient underwent pre- and postoperative comprehensive ophthalmologic examinations including determination of refractive error as spherical equivalent (SE) and corrected distant visual acuity (CDVA), slit lamp biomicroscopic examination, fundoscopy, and a detailed analysis on a Scheimplug+Placido device (Sirius, CSO, Florence, Italy). The riboflavin solution, which was composed of riboflavin 0.25% with hydroxypropyl methylcellulose (HPMC) and benzalkonium chloride (BAC) (ParaCel, Avedro), was used in the procedure. The cornea was exposed to ultraviolet A light (KXL System, Avedro Inc., Waltham, MS, USA) for 2 minutes and 40 seconds at an irradiance of 45 mW/cm2. RESULTS The mean age of the patients was 25.9 ± 4.0 (ranging from 18 to 33) years. No significant changes were observed in the mean CDVA, SE, and topographic indices at year 1 and year 2 visits compared to preoperative examination. The mean corneal thickness at the thinnest point was significantly higher at year 1 and year 2 visits than at preoperative examination (p1 = 0.014 and p2 = 0.017, respectively). No intra- or postoperative complications or adverse reactions were observed. CONCLUSIONS Transepithelial high-intensity (irradiance of 45 mW/cm2 for 2 minutes and 40 seconds) CXL using 0.25% riboflavin solution was a safe and effective method to halt the progression of keratoconus for a 2-year follow-up period.
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Affiliation(s)
| | - Kemal Türkyılmaz
- b Department of Ophthalmology , Recep Tayyip Erdoğan University Medical School , Rize , Turkey
| | - Veysi Öner
- b Department of Ophthalmology , Recep Tayyip Erdoğan University Medical School , Rize , Turkey
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