Long-term Results of an Accelerated Corneal Cross-linking Protocol (18 mW/cm2) for the Treatment of Progressive Keratoconus

PurposeTo compare the long-term outcomes of accelerated and standard corneal cross-linking protocols in the treatment of progressive keratoconus.DesignProspective randomized clinical trial.MethodsThirty-one eyes with keratoconus were treated with an accelerated protocol (18 mW/cm2, 5 min) and all contralateral eyes were treated with the standard method (3 mW/cm2, 30 min) using the same overall fluence of 5.4 J/cm2.ResultsAt 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/cm2 accelerated protocol, except K-reading (P = .059) and index surface variance (P = .034).ConclusionAn accelerated cross-linking protocol, using 18 mW/cm2 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.