Abstract
Purpose :
Primary treatment for progressive keratoconus is corneal collagen crosslinking (CXL). Patients having CXL are seeking answers whether they should have epithelium off or epithelium on CXL. The aim of this study was to assess the efficacy and safety of epithelium-off and epithelium-on CXL protocols in keratoconus.
Methods :
A prospective observational study was performed using real-world data of patients in routine clinical practice from the Save Sight Keratoconus Registry. Patients who were from Australia and had no prior intervention before CXL were included. Primary outcomes were change in Kmax, habitual corrected visual acuity (VA), K2, and minimum corneal thickness (MCT) at 12 months follow-up. Mixed effects regression models were used to evaluate changes in outcomes adjusted for age, sex, baseline outcomes, eye laterality and practices.
Results :
There were 49 eyes (37 patients) and 1170 eyes (888 patients) in the epithelium-on and epithelium-off CXL protocols, respectively. The mean age was comparable between the epithelium-on and epithelium-off group, 26 (SD 8.9) vs 25.9 (SD 7.4) years, respectively. At 12 months from the baseline, the mean change in Kmax was 0.4D (95% CI: -0.6, 1.4) with epithelium-on CXL vs 0.1D (-0.1, 0.3) with epithelium-off CXL. For epithelium-on CXL vs epithelium-off CXL respectively, the mean change in VA from baseline to 12 months was 1.0 (-0.8, 2.7) logMAR letters vs 0.7 (0,1.3) logMAR letters and change in K2 was -0.1D (-0.6,0.5) vs 0.1D (-0.1,0.2) in epithelium-on and off CXL which were not statistically significant (all p <0.05). The epithelium off group had greater corneal thinning with an MCT change of -14.3 µm (-16.2, -12.5) vs 0.5µm (-4,5.4) in the epithelium-on group (p <0.001). There were less adverse events recorded in epithelium-on relative to epithelium-off CXL.
Conclusions :
Epithelium-off and epithelium-on CXL protocols were similarly effective, as measured by VA and corneal curvature, in preventing keratoconus progression from the baseline to 12 months follow up.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.