Comparative study of changes of corneal curvatures and uncorrected distance visual acuity prior to and after corneal collagen crosslinking: 1-year results

BACKGROUND/PURPOSE Keratoconus is the most common primary corneal ectatic disease and has considerable importance in public health. Corneal collagen crosslinking (CXL) is a procedure to mitigate progression of keratoconus and reduce demand for corneal transplantation. The aim of this study was to evaluate the effect of CXL on corneal topographic and uncorrected distance visual acuity (UDVA) by Oculus Pentacam in the 15-30-year-old population. METHODS In this descriptive-analytic study, we enrolled 38 eyes of 27 patients suffering from progressive keratoconus who were candidates for CXL. UDVA and the anterior and posterior corneal curvatures assessed prior to and 12 months after CXL. Data were analyzed by the paired t test and p < 0.05 was considered significant. RESULTS One year after the CXL, mean UDVA significantly improved 0.1 ± 0.25 logarithm of the minimal angle of resolution (p = 0.012). Changes for steep keratometry values, flat keratometry, and mean keratometry on the anterior corneal surface were statistically significant (all p < 0.005). However, the difference observed in maximum keratometry and astigmatism was not significant (p = 0.421 and p = 0.745, respectively). After 12 months, all four keratometry values on the posterior corneal surface had increased significantly (p < 0.005), while no significant change observed in astigmatism (p = 0.303). CONCLUSION Corneal collagen crosslinking has been revealed as an effective and minimally invasive intervention for the treatment of progressive keratoconus that can improve UDVA.