Hassan Hashemi1, Mohammad Miraftab1, Mohammad Amin Seyedian1, Farhad Hafezi2, Hooman Bahrmandy1, Shahab Heidarian1, Kazem Amanzadeh1, Hamidreza Nikbin1, Akbar Fotouhi3, Soheila Asgari4. 1. Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran. 2. Center for Applied Biotechnology and Molecular Medicine (CABMM), University of Zurich, Zurich, Switzerland; Medical Faculty, University of Geneva, Geneva, Switzerland; Eye Care & Laboratory Research - Zurich Associates, Zurich, Switzerland; Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California. 3. Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 4. Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran. Electronic address: soheilaasgari@gmail.com.
Abstract
PURPOSE: To compare the long-term outcomes of accelerated and standard corneal cross-linking protocols in the treatment of progressive keratoconus. DESIGN: Prospective randomized clinical trial. METHODS:Thirty-one eyes with keratoconus were treated with an accelerated protocol (18 mW/cm(2), 5 min) and all contralateral eyes were treated with the standard method (3 mW/cm(2), 30 min) using the same overall fluence of 5.4 J/cm(2). RESULTS: At 18 months after the procedure, the standard group showed significant improvement in spherical equivalent (P < .05), K-readings (P < .05), Q value (P < .05), index of surface variance (P < .05), and keratoconus index (P = .008) and decline in central corneal thickness (P < .05), but no significant change in visual acuity, corneal hysteresis, corneal resistance factor, P2 area, or endothelial cell density. In the accelerated group, central corneal thickness was the only parameter with statistically significant change. However, neither of these parameters showed significant differences between the standard and the 18 mW/cm(2) accelerated protocol, except K-reading (P = .059) and index surface variance (P = .034). CONCLUSION: An accelerated cross-linking protocol, using 18 mW/cm(2) for 5 minutes, shows a comparable outcome and safety profile when compared to the standard protocol, but better corneal flattening is achieved with the standard method than the accelerated method. Overall, both methods stop the disease progression similarly. This study will continue to examine more long-term results.
RCT Entities:
PURPOSE: To compare the long-term outcomes of accelerated and standard corneal cross-linking protocols in the treatment of progressive keratoconus. DESIGN: Prospective randomized clinical trial. METHODS: Thirty-one eyes with keratoconus were treated with an accelerated protocol (18 mW/cm(2), 5 min) and all contralateral eyes were treated with the standard method (3 mW/cm(2), 30 min) using the same overall fluence of 5.4 J/cm(2). RESULTS: At 18 months after the procedure, the standard group showed significant improvement in spherical equivalent (P < .05), K-readings (P < .05), Q value (P < .05), index of surface variance (P < .05), and keratoconus index (P = .008) and decline in central corneal thickness (P < .05), but no significant change in visual acuity, corneal hysteresis, corneal resistance factor, P2 area, or endothelial cell density. In the accelerated group, central corneal thickness was the only parameter with statistically significant change. However, neither of these parameters showed significant differences between the standard and the 18 mW/cm(2) accelerated protocol, except K-reading (P = .059) and index surface variance (P = .034). CONCLUSION: An accelerated cross-linking protocol, using 18 mW/cm(2) for 5 minutes, shows a comparable outcome and safety profile when compared to the standard protocol, but better corneal flattening is achieved with the standard method than the accelerated method. Overall, both methods stop the disease progression similarly. This study will continue to examine more long-term results.
Authors: Hany A Khairy; Moataz F Elsawy; Khaled Said-Ahmed; Marwa A Zaki; Sameh S Mandour Journal: Int J Ophthalmol Date: 2019-11-18 Impact factor: 1.779