Impression cytologic analysis after corneal collagen cross-linking using riboflavin and ultraviolet-A light in the treatment of keratoconus.

PURPOSE: To report impression cytologic (IC) results after corneal cross-linking (CXL) using riboflavin and ultraviolet-A light in the treatment of keratoconus and compare the data with those from a group of subjects with the same disease. METHODS: Forty eyes were distributed into 2 groups: patients in group 1 underwent CXL, whereas patients in group 2 received riboflavin 0.1% eyedrops for 1 month of topical use. IC specimens were obtained from all eyes before treatment and 1 and 3 months after treatment. RESULTS: Patients in group 1 showed a decrease in goblet cell density on the superior conjunctiva after CXL (P = 0.008) but no difference on the temporal conjunctiva or in the cornea. Patients in group 2 demonstrated improvement in cell-to-cell contact of epithelial cells and reduced keratinization on the temporal conjunctiva after treatment (P = 0.003 and P = 0.034, respectively) but no changes on the superior conjunctiva or in the cornea. Fisher exact test comparison of IC total scores after treatment revealed no difference between groups. CONCLUSIONS: Despite changes in goblet cell density after corneal CXL in the superior conjunctiva and an improvement in the morphology of epithelial cells after the use of riboflavin eyedrops, comparison of total IC scores showed no difference between groups.