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Fasciani R, Scartozzi L, Bruzio S, Di Stefano G, Mosca L, Guccione L, Ciardiello A, Rizzo S. High-Fluence Epithelium-off Accelerated Pulsed Corneal Cross-linking (15 mW/cm 2; 7.2 J/cm 2) for Pediatric Keratoconus: A 3-Year Retrospective Analysis. J Refract Surg 2024; 40:e148-e155. [PMID: 38466760 DOI: 10.3928/1081597x-20240208-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
PURPOSE To assess the safety and efficacy of treatment and secondarily determine the topographic changes, visual outcomes, and demarcation line depth after high-fluence pulsed light accelerated cross-linking (ACXL) in pediatric patients (younger than 18 years) with progressive keratoconus. METHODS This retrospective analysis included 32 eyes (25 children, aged 11 to 18 years), with progressive keratoconus treated with high-energy epithelium-off pulsed light ACXL (7.2 J/cm2, 15 mW/cm2, 12 minutes, 2 seconds on/1 second off). Corrected distance visual acuity (CDVA), Scheimpflug tomography, and anterior optical coherence tomography measurements were recorded preoperatively and 1, 2, and 3 years postoperatively. RESULTS A total of 32 eyes were included. Significant CDVA improvement, pachymetry, and maximum keratometry reduction were found at all follow-up visits. Mean keratometric values remained stable, and astigmatism showed a mild worsening (< 0.25 D) with statistical significance at 1 and 3 years. Total aberration showed discordant results and coma aberration had a slight improvement without statistical significance. The demarcation line depth was 265 ± 26 μm. Three patients developed mild haze without visual acuity loss. None of the patients underwent a second CXL procedure. CONCLUSIONS In pediatric patients, high-fluence epithelium-off pulsed light ACXL appears to be a safe and effective procedure to halt the progression of keratoconus, slightly improving the CDVA and keratometric values. [J Refract Surg. 2024;40(3):e148-e155.].
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Prasher P, Sharma A, Sharma R, Vig VK, Nirankari VS. Paediatric cornea crosslinking current strategies: A review. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:55-62. [PMID: 37846374 PMCID: PMC10577868 DOI: 10.1016/j.aopr.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/13/2022] [Accepted: 11/16/2022] [Indexed: 10/18/2023]
Abstract
Background In the general population, 1 in 2000 people has keratoconus. Indians and other people from Southeast Asia have a higher incidence of keratoconus. Children with keratoconus typically present earlier in life and with a more severe disease. Rubbing the eyes has been identified as a risk factor. Children have a higher incidence and a faster rate of keratoconus progression. Visual rehabilitation in children with keratoconus is challenging. They have a low compliance with contact lens use. Many of these children require penetrating keratoplasty at an early age. Therefore, stopping the progression of keratoconus in children is of paramount importance. Main text Compared to treatment, keratoconus progression prophylaxis is not only preferable, but also easier. Corneal collagen cross-linking has been shown to be safe and effective in stopping its progression in children. The Dresden protocol, which involves central corneal deepithelization (7-9 mm), saturation of the stroma with riboflavin (0.25%), and 30 min UV-A exposure, has proven to be the most successful. Two significant disadvantages of the typical Dresden regimen are the prolonged operating time and the significant post-operative pain. Accelerated-CXL (9 mW/cm2 x 10 min) has been studied to reduce operative time and has been shown to be equally effective in some studies. Compared to accelerated CXL or traditional CXL, epi-off procedures, transepithelial treatment without the need for de-epithelialization and without postoperative discomfort, have been shown to be safer but less effective. Corneal crosslinking should only be performed after treating children with active vernal keratoconjunctivitis. Corneal opacity, chronic corneal edema, sterile infiltrates, and microbial keratitis have been reported after cross-linking of corneal collagen. Conclusions The "Dresden protocol", also known as the conventional corneal cross-linking approach, should be used to halt the progression of keratoconus in young patients. However, if the procedure needs to be completed more rapidly, accelerated corneal crosslinking may be considered. Transepithelial corneal cross-linking has been proven to be less effective at stabilizing keratoconus, although being more safer.
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Affiliation(s)
- Pawan Prasher
- Department of Ophthalmology, Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India
| | - Ashok Sharma
- Cornea Centre, SCO 2463 - 2464, Sector 22 C, 160022, Chandigarh, India
| | - Rajan Sharma
- Cornea Centre, SCO 2463 - 2464, Sector 22 C, 160022, Chandigarh, India
| | - Vipan K. Vig
- Amritsar Eye Hospital, GNDU Shopping Complex, Amritsar, Punjab, India
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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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Polido J, Dos Xavier Santos Araújo ME, Alexander JG, Cabral T, Ambrósio R, Freitas D. Pediatric Crosslinking: Current Protocols and Approach. Ophthalmol Ther 2022; 11:983-999. [PMID: 35482230 PMCID: PMC9114245 DOI: 10.1007/s40123-022-00508-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 03/31/2022] [Indexed: 11/24/2022] Open
Abstract
Keratoconus (KC) is likely to be more aggressive in the pediatric population, with a higher risk of progression and visual loss. Several techniques have been proposed for corneal crosslinking (CXL) so far. The standard CXL (SCXL) technique, or the Dresden Protocol, originally developed by Wollensak et al., has been shown to be safe and effective in the pediatric KC group. With similar efficacy to the conventional method, the accelerated CXL (ACXL) protocols proposed a reduced UVA exposure time by increasing the intensity of UVA irradiation. Transepithelial CXL (TCXL), considered an "epithelium-on" method, emerged as a strategy to improve safety and reduce postoperative complications and discomfort. For thinner corneas, we can highlight the use of hypoosmolar riboflavin and new studies, such as contact lens-assisted CXL (CACXL), the epithelial-island CXL (EI-CXL), and the Sub400 protocol. In addition to the different protocols used, another factor that changes CXL results is the type of carrier used: dextran-based or hydroxypropyl methylcellulose-based (HPMC) riboflavin solutions. There are several ways to perform a CXL surgery, and it is still unclear which method is the safest and most effective in the pediatric group. This review of the literature in English, available in PubMed, provides an update on corneal CXL in the pediatric KC group, exploring the data on the techniques currently used and under investigation, including their advantages, efficacy, safety profiles, risks, and cost analyses.
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Affiliation(s)
- Júlia Polido
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.
| | - Maria Emília Dos Xavier Santos Araújo
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.,Department of Ophthalmology, HSPE/IAMSPE, São Paulo, SP, Brazil
| | - João G Alexander
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil
| | - Thiago Cabral
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.,Department of Ophthalmology EBSERH, HUCAM/CCS-UFES, Federal University of Espírito Santo (UFES), Vitória, ES, Brazil
| | - Renato Ambrósio
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil.,Department of Ophthalmology, The Federal University of the State of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Denise Freitas
- Department of Ophthalmology, Federal University of São Paulo (UNIFESP), Rua Botucatu, 806, Vila Clementino, São Paulo, SP, CEP 04023-062, Brazil
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Analysis of Tear Function Outcomes following Collagen Cross-Linking Treatment in Ectatic Corneas. J Ophthalmol 2022; 2022:1910607. [PMID: 35321348 PMCID: PMC8938138 DOI: 10.1155/2022/1910607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 11/17/2022] Open
Abstract
Purpose To analyze tear function outcomes following collagen cross-linking (CXL) treatment in ectatic corneas. Methods Fifty-seven eyes of 34 patients were included, and patients with keratoconus who underwent epithelium-on (epi-on) or epithelium-off (epi-off) CXL were evaluated. The following tests were performed preoperatively and at 1, 3, 6, and 12 months postoperatively: best-corrected visual acuity (BCVA), maximum keratometry value (Kmax), ocular surface disease index (OSDI) questionnaire, slit-lamp examination, tear meniscus height, first noninvasive Keratograph breakup time (1st NIKBUT), average NIKBUT, and bulbar redness. Results BCVA improved in both epi-on and epi-off groups at most follow-up points, but was not significantly different between groups. At 12-month follow-up, Kmax in the epi-on and epi-off groups improved after CXL, but there was no significant difference between the groups. The OSDI in both groups decreased after operation compared with before surgery, and there was no significant difference between the two groups. Comparing the two groups, only the change in the tear meniscus height at 6 months postoperatively was statistically significant, and the pre- and postoperative values of the two groups were within the normal range (>0.20 mm). The change was small and had no clinical significance. There was no change in the 1st NIKBUT and average NIKBUT between the epi-on and epi-off groups. A change in bulbar redness was significantly better in the epi-off group than in the epi-on group at 3 months postoperatively. Comparing the effects at 1 year postoperatively, both groups had positive results in OSDI, NIKBUT, tear meniscus height, and bulbar redness. Conclusion Both epi-on and epi-off CXL can control the progression of keratoconus, although epi-off CXL is more effective. Both methods have a positive effect on dry eye, which can improve the condition of the tear film and reduce dry eye symptoms in patients with keratoconus.
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Li Y, Lu Y, Du K, Yin Y, Hu T, Fu Y, Xiang A, Fu Q, Wu X, Wen D. Comparison of Efficacy and Safety Between Standard, Accelerated Epithelium-Off and Transepithelial Corneal Collagen Crosslinking in Pediatric Keratoconus: A Meta-Analysis. Front Med (Lausanne) 2022; 9:787167. [PMID: 35372437 PMCID: PMC8968048 DOI: 10.3389/fmed.2022.787167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/15/2022] [Indexed: 01/10/2023] Open
Abstract
Purpose The purpose of the study is to compare the efficacy of standard epithelium-off CXL (SCXL), accelerated epithelium-off CXL (ACXL), and transepithelial crosslinking CXL (TECXL) for pediatric keratoconus. Methods A literature search on the efficacy of SCXL, ACXL, and TECXL [including accelerated TECXL (A-TECXL)] for keratoconus patients younger than 18 years was conducted using PubMed, Cochrane Library, ClinicalTrials.gov, and EMBASE up to 2021. Primary outcomes were changes in uncorrected visual acuity (UCVA) and maximum keratometry (Kmax) after CXL. Secondary outcomes were changes in best-corrected visual acuity (BCVA), mean refractive spherical equivalent (MRSE), and central corneal thickness (CCT). Estimations were analyzed by weighted mean difference (WMD) and 95% confidence interval (CI). Results A number of eleven identified studies enrolled 888 eyes (SCXL: 407 eyes; ACXL: 297 eyes; TECXL: 28 eyes; A-TECXL: 156 eyes). For pediatric keratoconus, except for a significant greater improvement in BCVA at 24-month follow-up in SCXL (WMD = –0.08, 95%CI: –0.14 to –0.01, p = 0.03, I2 = 71%), no significant difference was observed in other outcomes between the SCXL and ACXL groups. SCXL seems to provide greater changes in UCVA (WMD = –0.24, 95% CI: –0.34 to –0.13, p < 0.00001, I2 = 89%), BCVA (WMD = –0.09, 95% CI: –0.15 to –0.04, p = 0.0008, I2 = 94%), and Kmax (WMD = –1.93, 95% CI: –3.02 to –0.85, p = 0.0005, I2 = 0%) than A-TECXL, with higher incidence of adverse events. Conclusion For pediatric keratoconus, both SCXL and ACXL appear to be comparable in the efficacy of visual effects and keratometric outcomes; SCXL seems to provide greater changes in visual and pachymetric outcomes than A-TECXL.
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Affiliation(s)
- Yuanjun Li
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Ying Lu
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Kaixuan Du
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yewei Yin
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Tu Hu
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Yanyan Fu
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Aiqun Xiang
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Qiuman Fu
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Xiaoying Wu
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Dan Wen
- Eye Center of Xiangya Hospital, Hunan Key Laboratory of Ophthalmology, Xiangya Hospital, Central South University, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
- *Correspondence: Dan Wen,
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Salman A, Ali A, Rafea S, Omran R, Kubaisi B, Ghabra M, Darwish T. Long-term visual, anterior and posterior corneal changes after crosslinking for progressive keratoconus. Eur J Ophthalmol 2021; 32:50-58. [PMID: 34719971 DOI: 10.1177/11206721211052878] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
AIM To evaluate the long-term outcomes of corneal cross-linking (CXL) in patients with progressive keratoconus. METHOD In this retrospective non-comparative study, forty-five eyes of 31 patients with progressive keratoconus were treated with 30 min "epi-off" corneal cross-linking. The visual, refractive, topographic and tomographic outcomes were evaluated preoperatively and at least 10 years after cross-linking. RESULTS Ten years post-corneal cross-linking, the mean anterior maximum keratometry decreased (-2.10 ± 3.25 D, P = 0.0001). Conversely, the posterior maximum keratometry increased (6.38 ± 9.79 D, P = 0.065). Both uncorrected and corrected distance visual acuity improved (LogMAR -0.08 ± 0.30) and (LogMAR -0.05 ± 0.21), respectively (P > 0.05, both). A statistically significant hyperopic shift was observed postoperatively (0.70 ± 1.31 D, P = 0.0009). The anterior topographic cylinder values revealed no change (-0.17 ± 1.31 D, P = 0.3), whereas the mean posterior cylinder values decreased (absolute value increased) significantly compared to baseline from -1.31 ± 0.97 D to -1.82 ± 1.78 D, (P < 0.05). The minimum corneal thickness values decreased significantly (-35.11 ± 48.63 µm, P = 0.0001). Four eyes (8.8%) showed more than 1 D increase in the anterior maximum keratometry. CONCLUSION This protocol and duration of Epi-off corneal cross-linking was found to be effective in halting keratoconus progression over the follow up period (10 years). Anterior corneal flattening and a hyperopic shift were observed. A statistically significant increase in the posterior corneal cylinder was observed. Although, not reaching statistical significance, the logMAR uncorrected and corrected visual acuity were improved.
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Affiliation(s)
- Abdelrahman Salman
- Honorary Clinical Lecturer at Tishreen University, Scientific Director of Tratous Specialist Eye Center(Tartous, Syria), Lattakia, Syrian Arab Republic
| | - Ali Ali
- Department of Ophthalmology, 37585Tishreen University, Latakia, Syria
| | - Shaaban Rafea
- Faculty of Medicine Tartous, 536622Tartous University, Tartous, Syria.,Faculty of Medicine, Al-Andalus University for Medical Science, Tartous, Syria
| | - Rana Omran
- Head of Department of Ophthalmology, Eye Surgical Hospital, Damascus, Syria
| | - Buraa Kubaisi
- Head of Cornea Unit, Eye Surgical Hospital Damascus, Damascus, Syria
| | - Marwan Ghabra
- 114768Arab International University, Damascus, Syria
| | - Taym Darwish
- Department of Ophthalmology, 37585Tishreen University, Latakia, Syria
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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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Aydın E, Aslan MG. The efficiency and safety of oxygen-supplemented accelerated transepithelial corneal cross-linking. Int Ophthalmol 2021; 41:2993-3005. [PMID: 33876334 DOI: 10.1007/s10792-021-01859-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 04/08/2021] [Indexed: 12/17/2022]
Abstract
PURPOSE To investigate the impact of oxygen delivery on the clinical outcomes of accelerated transepithelial corneal cross-linking (A-TE CXL). METHODS Fifty-seven eyes of 44 progressive keratoconus (KCN) patients were randomly separated into two age-sex-matched groups. Twenty-nine eyes of 23 KCN patients that underwent oxygen-supplemented A-TE CXL formed the study group and 28 eyes of 21 patients treated with the same procedure but under room air conditions formed the control group. All patients were examined preoperatively, one, six and twelve months after the procedure. The logMAR spectacle-corrected distance visual acuity (CDVA), maximum keratometry (Kmax), mean keratometry, apical posterior keratometry, cylindrical power, minimum central corneal thickness, keratoconus vertex front and back, ocular aberrations, endothelial cell density (ECD), demarcation line depth (DLD) and proportion measures were recorded for statistical analysis. RESULTS The preoperative, 1st, 6th and 12th months mean Kmax values of the study group were 55.14 ± 3.99D, 54.85 ± 3.82D, 54.37 ± 3.84D and 54.40 ± 3.86, respectively, and 54.47 ± 3.17D, 54.52 ± 2.97D, 54.25 ± 2.95D and 54.20 ± 2.97 in the control group. The mean Kmax value was decreased significantly more in the oxygen-supplemented group after 12 months compared to the control group (p = 0.019). The mean DLD was also significantly deeper in the study group (320 ± 17 µm) compared to the control group (269 ± 19 µm). There was no significant difference between the two groups in terms of ECD alterations at any of the time intervals (p > 0.05). CONCLUSION Keratoconus progression was significantly halted in both groups 12 months after the treatment. In addition, oxygen supplementation during A-TE CXL further significantly increased clinical outcomes compared to room air conditions without any significant change in ECD measures.
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Affiliation(s)
- Emre Aydın
- Department of Ophthalmology, Recep Tayyip Erdogan University Medical Faculty, Rize, Turkey
| | - Mehmet Gökhan Aslan
- Department of Ophthalmology, Recep Tayyip Erdogan University Medical Faculty, Rize, Turkey.
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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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Corneal collagen cross-linking in pediatric keratoconus with three protocols: a systematic review and meta-analysis. J AAPOS 2020; 24:331-336. [PMID: 33279597 DOI: 10.1016/j.jaapos.2020.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/31/2020] [Accepted: 08/16/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Keratoconus is a bilateral progressive noninflammatory degenerative disease of the cornea characterized by corneal thinning, irregular astigmatism, and subsequent visual impairment. It has an aggressive course in children. This systematic review evaluates the efficacy of available corneal collagen cross-linking (CXL) protocols for stabilizing the cornea in pediatric patients with keratoconus. METHODS We searched all peer-reviewed publications from 2000 to 2019 indexed in PubMed, Google Scholars, Web of Science, and Cochrane's Database for the terms keratoconus and cross-linking. The following data were extracted from eligible studies: study design, type of intervention, number of the eyes and mean age of patients for each study, duration of follow-up period, mean pre- and postoperative uncorrected and corrected visual acuity, keratometric and aberrometric indices, were analyzed with RevMan 5.3 software. Intra-and intergroup post hoc analyses of outcome variables were performed using t tests. RESULTS A total of 28 studies, including 1,300 eyes, were reviewed. In conventional and accelerated epithelium-off techniques, there was a significant improvement in uncorrected and corrected visual acuities. Similarly, the keratometric indices improved significantly after CXL. Uncorrected visual acuity did not alter after CXL using transepithelial method. CONCLUSIONS Both conventional and accelerated collagen CXL of the cornea are effective therapeutic options in management of keratoconus in children.
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Antunes-Foschini R, Faria-E-Sousa SJ. Three-year follow-up in advanced pediatric keratoconus: thin corneas may not have pachymetry properly assessed after crosslinking. Int J Ophthalmol 2020; 13:1561-1566. [PMID: 33078105 DOI: 10.18240/ijo.2020.10.08] [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: 04/22/2020] [Accepted: 05/18/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To analyze the crosslinking (CXL) effects in pediatric keratoconus, and to identify the patients' corneal characteristics whose pachymetry could not be adequately evaluated by Scheimpflug method after procedure. METHODS Consecutive pediatric patients with progressive keratoconus underwent CXL were included. Best-corrected visual acuity (BCVA) and spheric equivalent (SE) were measured before and after CXL. After CXL, groups 1 and 2 were divided based on the posterior surface Pentacam quality specifications (QS): "OK" (Group 1) and "not OK" (Group 2). The mean (RmF and RmB) and minimum (RminF and RminB) radius of curvatures of the anterior and posterior corneal surfaces, and the thinnest pachymetry (Pmin) were measured preoperatively at 3, 6, 12, 24, and 36mo. Haze was annotated. RESULTS Twenty-six patients (14 men, mean age 14±1.8y) and median Kmax of 59.9 D initially and 61.4 D preoperatively were treated. BCVA was not different before and 24mo after CXL. Group 2 statistically differed to group 1 in that SE was more myopic before and with no difference 24mo after CXL; RmF and RmB were steeper and Pmin was thinner pre-surgically. Group 2, in which pachymetric changes could not be adequately evaluated after surgery, presented with significant RmF flattening, a shift to hyperopia, and more haze after CXL. CONCLUSION Patients whose pachymetry could not be adequately evaluated after CXL had steeper and thinner corneas before surgery. The predictive factors for impaired QS after CXL are RmF, RmB, and Pmin. In advanced keratoconus, alternative methods to analyze pachymetry and the posterior surface should be considered.
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Affiliation(s)
- Rosalia Antunes-Foschini
- Hospital das Clínicas, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Sidney Júlio Faria-E-Sousa
- Department of Ophthalmology, Otorhinolaryngology, Head and Neck Surgery, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto 14049-900, Brazil
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13
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Aslan MG, Fındık H, Okutucu M, Aydın E, Uzun F. The impact of hybrid contact lenses on keratoconus progression after accelerated transepithelial corneal cross-linking. Int Ophthalmol 2020; 41:45-55. [PMID: 32856196 DOI: 10.1007/s10792-020-01551-w] [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: 05/06/2020] [Accepted: 08/16/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To investigate the effect of hybrid contact lenses (HCLs) on keratoconus (KCN) progression after accelerated transepithelial cross-linking (A-TE CXL). METHODS Thirty-five eyes of 26 patients who preferred Ultrahealth HCLs for an optical correction after A-TE CXL formed the study group, and 45 eyes of 34 patients who preferred spectacle correction were age- and sex-matched to form the control group. Corrected distance visual acuity (CDVA), maximum keratometry, mean keratometry, apical posterior keratometry, cylindrical power, minimum corneal thickness, keratoconus vertex indices and curvature asymmetry indices obtained by Scheimpflug corneal topography were compared before, 6 and 12 months after the procedure. Anterior segment optic coherence tomography (AS-OCT) was performed to measure the apical corneal clearance of HCL-wearing patients. RESULTS The median pre-CXL CDVA value of the patients in the HCL group was logMAR 0.30 (0.20-1.0), and it was logMAR 0.30 (0.10-1.0) in the spectacle-corrected group. There was a significant increase in CDVA 6 and 12 months after CXL procedure in both groups (p < 0.001, 0.003, respectively). The median front curve asymmetry index (FCAsym) significantly improved after A-TE CXL in the HCL group. The pre-CXL and 12th-month topographic comparisons of the spectacle-corrected group revealed no significant difference. In addition, no significant difference was observed between topographic alterations of two groups (p > 0.05). CONCLUSION The CDVA significantly improved, and KCN progression was halted in patients wearing HCL 12 months after A-TE CXL. Besides, FCAsym indices can be considered for follow-up of the HCL-wearing patients as an assistive parameter to AS-OCT measurements.
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Affiliation(s)
- Mehmet Gökhan Aslan
- Department of Ophthalmology, Recep Tayyip Erdogan University Medical Faculty, Islampasa Mah, 53020, Merkez, Rize, Turkey.
| | - Hüseyin Fındık
- Department of Ophthalmology, Recep Tayyip Erdogan University Medical Faculty, Islampasa Mah, 53020, Merkez, Rize, Turkey
| | - Murat Okutucu
- Department of Ophthalmology, Recep Tayyip Erdogan University Medical Faculty, Islampasa Mah, 53020, Merkez, Rize, Turkey
| | - Emre Aydın
- Department of Ophthalmology, Recep Tayyip Erdogan University Medical Faculty, Islampasa Mah, 53020, Merkez, Rize, Turkey
| | - Feyzahan Uzun
- Department of Ophthalmology, Recep Tayyip Erdogan University Medical Faculty, Islampasa Mah, 53020, Merkez, Rize, Turkey
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14
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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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15
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Long-Term Results of Accelerated Corneal Cross-Linking in Adolescent Patients With Keratoconus. Cornea 2019; 38:992-997. [DOI: 10.1097/ico.0000000000001975] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Mukhtar S, Ambati BK. Pediatric keratoconus: a review of the literature. Int Ophthalmol 2018; 38:2257-2266. [PMID: 28852910 PMCID: PMC5856649 DOI: 10.1007/s10792-017-0699-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 08/18/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE To describe the epidemiology and prevalence, rates of progression, difference between adult and pediatric populations, and therapeutic approaches to pediatric keratoconus from documented literature. METHODS A literature search was done on PubMed using key words including pediatric keratoconus, children with keratoconus, adult keratoconus, penetrating keratoplasty, corneal cross-linking and intracorneal ring segments. The literature was reviewed and reported to explore the key epidemiological differences between the pediatric and adult population with regards to presentation and treatment options. RESULTS Pediatric keratoconus is more aggressive than adult keratoconus, which has been explained by structural differences in the cornea between both populations. High rates of progression were documented in pediatric populations. While corneal collagen cross-linking, intracorneal ring segments and penetrating keratoplasties have been used as therapies in the pediatric population, the literature overwhelmingly shows higher rates of failure and progression despite these measures as compared to adults. CONCLUSION Pediatric keratoconus is more aggressive than adult keratoconus, and current therapies used in adults may not be sufficient for the pediatric population.
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Affiliation(s)
- Sabrina Mukhtar
- School of Medicine, Virginia Commonwealth University, 1201 E. Marshall St., 4th Floor, Richmond, VA, 232983, USA.
| | - Balamurali K Ambati
- Moran Eye Center, University of Utah, 64 Mario Capecchi Dr, Salt Lake City, UT, 84132, USA
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17
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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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18
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Abstract
PURPOSE To comprehensively review the available published literature for cross-linking in the pediatric population. METHODS Review of the literature published in English in PubMed. RESULTS Two hundred ten publications were considered. One hundred fifteen were considered relevant to this review. CONCLUSIONS Studies of cross-linking in pediatric patients are sparse, with relatively short follow-up times, and mostly on small groups of patients. Treatment with cross-linking halts progression of keratoconus in the pediatric population, and early treatment seems to be cost-effective compared with later penetrating keratoplasty. Long-term effects and regression rates remain unclear, and further studies are needed in this population.
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Affiliation(s)
- Claudia Perez-Straziota
- Department of Ophthalmology, University of Southern California, Los Angeles, CA
- Cornea Eye Institute, Beverly Hills, CA
| | - Ronald N Gaster
- Cornea Eye Institute, Beverly Hills, CA
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA
| | - Yaron S Rabinowitz
- Cornea Eye Institute, Beverly Hills, CA
- Ophthalmology Research, Cedars-Sinai Medical Center, Los Angeles, CA
- Department of Ophthalmology, Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA
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19
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Subasinghe SK, Ogbuehi KC, Dias GJ. Current perspectives on corneal collagen crosslinking (CXL). Graefes Arch Clin Exp Ophthalmol 2018; 256:1363-1384. [PMID: 29623463 DOI: 10.1007/s00417-018-3966-0] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 02/20/2018] [Accepted: 03/23/2018] [Indexed: 12/13/2022] Open
Abstract
Corneal collagen crosslinking has revolutionized the treatment of keratoconus and post-refractive corneal ectasia in the past decade. Corneal crosslinking with riboflavin and ultraviolet A is proposed to halt the progression of keratectasia. In the original "Conventional Dresden Protocol" (C-CXL), the epithelium is removed prior to the crosslinking process to facilitate better absorption of riboflavin into the corneal stroma. Studies analyzing its short- and long-term outcomes revealed that although there are inconsistencies as to the effectiveness of this technique, the advantages prevail over the disadvantages. Therefore, corneal crosslinking (CXL) is widely used in current practice to treat keratoconus. In an attempt to improve the visual and topographical outcomes of C-CXL and to minimize time-related discomfort and endothelial-related side effects, various modifications such as accelerated crosslinking and transepithelial crosslinking methods have been introduced. The comparison of outcomes of these modified techniques with C-CXL has also returned contradictory results. Hence, it is difficult to clearly identify an optimal procedure that can overcome issues associated with the CXL. This review provides an up-to-date analysis on clinical and laboratory findings of these popular crosslinking protocols used in the treatment of keratoconus. It is evident from this review that in general, these modified techniques have succeeded in minimizing the immediate complications of the C-CXL technique. However, there were contradictory viewpoints regarding their effectiveness when compared with the conventional technique. Therefore, these modified techniques need to be further investigated to arrive at an optimal treatment option for keratoconus.
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Affiliation(s)
- Sandeepani K Subasinghe
- Department of Anatomy, University of Otago, P.O. Box 913, 270 Great King Street, Dunedin, 9054, New Zealand.
| | - Kelechi C Ogbuehi
- Ophthalmology Section, Department of Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - George J Dias
- Department of Anatomy, University of Otago, P.O. Box 913, 270 Great King Street, Dunedin, 9054, New Zealand
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20
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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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21
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Primary Outcomes of Accelerated Epithelium-Off Corneal Cross-Linking in Progressive Keratoconus in Children: A 1-Year Prospective Study. J Ophthalmol 2017; 2017:1923161. [PMID: 29464114 PMCID: PMC5804401 DOI: 10.1155/2017/1923161] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 11/23/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose To evaluate corneal transparency following accelerated collagen cross-linking (ACXL) in pediatric keratoconus. Design A prospective interventional case series. Methods This study included 47 eyes (25 patients), aged 9–14 years, with documented progressive keratoconus. After applying 0.1% riboflavin drops, ACXL was performed. Assessment included corrected distance visual acuity (CDVA), uncorrected visual acuity (UCVA), corneal haze, and corneal densitometry in grayscale units (GSU). Result The mean baseline and corneal densitometry peaked at 3 months post-ACXL while central and posterior densitometry showed a statistically significant increase (P < 0.05) and peaked at 8 months postoperatively. By 12 months, densitometry in all corneal layers (P ≥ 0.99) and concentric zones (P ≥ 0.97) reached near baseline values. Slit-lamp graded haze peaked at 1 month to 1.82 ± 0.65 (P < 0.05) and declined to near baseline at 12 months (0.39 ± 0.58). There was a statistically significant increase in the mean UCVA and CDVA at 12 months. Conclusion Total and anterior corneal densitometry peaked after 3 months, while central and posterior densitometry peaked after 8 months. Maximum haze was at 1 month post-ACXL. All corneal layers, concentric zone densitometry and haze reached near baseline values after 1 year. Scheimpflug densitometry showed weak correlation with CDVA over the 12-month follow-up period (r = −0.193).
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Long-term outcomes of corneal cross-linking for keratoconus in pediatric patients. J AAPOS 2017; 21:397-401. [PMID: 28935449 DOI: 10.1016/j.jaapos.2017.07.205] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/10/2017] [Accepted: 07/14/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE To report the long-term outcomes of corneal cross-linking (CXL) in pediatric patients with bilateral progressive keratoconus. METHODS The medical records of consecutive pediatric patients with bilateral progressive keratoconus who underwent CXL at a single institution from June 2007to December 2009 were reviewed. All eyes underwent CXL treatment in accordance with the original Dresden protocol. Pre- and post-operative (at 1 year and >5 years after CXL) examinations included, corneal thickness (CT) at the thinnest point, corneal topographic evaluation (flat, steep meridian keratometry and maximum keratometry), with manifest refraction and corrected distance visual acuity. RESULTS A total of 20 eyes of 10 patients were included. Mean age at time of CXL was 14.34 ± 2.14 years (range, 10.49-17.09 years). Mean follow-up was 7.63 ± 1.31 years (range, 5.41-9.34 years). No intra- or postoperative complications were observed. Stabilization of all topographic indices (steep K, flat K, Kmax, and topographic cylinder) was demonstrated throughout the follow-up period (compared to preoperative topographic indices [P < 0.05]). Mean corrected distance visual acuity improved to 0.14 ± 0.16 logMAR at final follow-up from the preoperative values 0.28 ± 0.17 logMAR (P > 0.05); none of the eyes lost corrected distance visual acuity lines. Manifest refraction and mean corneal pachymetry at the thinnest point remained stable throughout the follow-up (P < 0.05). CONCLUSIONS In this case series CXL (Dresden protocol) for pediatric keratoconus halted disease progression and offered improved visual function up to 7.5 years after treatment.
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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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