The outcome of corneal collagen cross-linking in progressive keratoconus: A 24-month follow-up

Purpose: The purpose of this study is to evaluate the effect of corneal collagen cross-linking on visual acuity and corneal parameters like keratometry and pachymetry. Methods: It was a retrospective, noncomparative, open-label study conducted at a tertiary eye care center. The eyes that underwent epithelium-off CXL (corneal collagen cross-linking) for progressive keratoconus between 2018 January and 2019 December, and who completed 24 months' post-CXL follow-up, were included in the study. Data regarding uncorrected and best spectacle-corrected visual acuity (UCVA and BSCVA) and corneal topography parameters, that is, K max , K min , and pachymetry at thinnest point, were collected prior to the procedure and 2 years after the procedure. Results: A total of 92 eyes of 65 patients were included in the study. There was a significant improvement of logMAR BCVA from preoperative 0.40 ± 0.24 to 0.28 ± 0.19 at 24 months after CXL ( P < 0.001). UCVA also increased from preoperative value of logMAR 0.70 ± 0.28 to 0.61 ± 0.26 2 years postoperatively ( P < 0.001). The number of eyes achieving BCVA of 0.3 logMAR or better significantly increased from 54 (58.7%) preoperatively to 72 (78.26%) at 2 years and it was found to be statistically significant ( P < 0.001). There was a significant improvement in K max 49.38 ± 3.70 to 49.07 ± 3.45 ( P = 0.0005) and K min 45.65 ± 2.69 to 45.19 ± 2.46 ( P < 0.001) following CXL. Conclusion: Corneal collagen cross-linking is a treatment modality to stabilize and even improve UCVA in patients with mild-to-moderate keratoconus.