Treatment of Acanthamoeba keratitis by corneal cross-linking.

PURPOSE: To evaluate the efficacy of corneal cross-linking (CXL; riboflavin/ultraviolet A) as a simple therapy for Acanthamoeba keratitis. METHODS: Twenty rabbits were systemically anesthetized and the stroma of their right corneas was inoculated with a suspension of Acanthamoeba. Rabbits were divided into 2 groups: one group was treated with corneal CXL 3 days after infection and the other did not receive any treatment (control). All eyes in both groups were examined before (days 0 and 3) and after (day 7) CXL treatment. On day 7, the eyes were enucleated; 18 corneal buttons (9 of each group) were sent for microbiological examination and 2 (1 of each group) for histopathologic examination. RESULTS: All animals developed Acanthamoeba keratitis. There was no statistically significant difference between groups before treatment (day 0, P = 1, and day 3, P = 0.684). The treated corneas had a higher score (3.48 ± 0.30) at the time of enucleation compared with control corneas (2.60 ± 0.26). This difference was statistically significant (P = 0.008). Microbiological analysis revealed that the treated corneas had a higher protozoal count (2.86 ± 0.09) compared with the control corneas (2.18 ± 0.07); this difference was statistically significant (P = 0.001). CONCLUSIONS: Treatment of Acanthamoeba keratitis by corneal CXL (riboflavin/ultraviolet A) did not prove effective in decreasing the intensity and severity of Acanthamoeba keratitis.