Corneal collagen cross-linking with riboflavin and UVA irradiation in pellucid marginal degeneration

PURPOSE: To report the results of corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A irradiation in a patient affected by pellucid marginal degeneration (PMD). METHODS: A 43-year-old man with bilateral PMD underwent CXL in the left eye. The treatment was performed in standard fashion with the exception of slightly inferior decentration of the 9 mm-diameter irradiated area preserving an untreated surface area 1 mm from the limbus. RESULTS: Epithelial regrowth was complete after 4 days' use of a bandage soft contact lens. No side effects or damage to the limbal region were observed during re-epithelialization or during follow-up. Corrected distance visual acuity improved from 20/200 to 20/63 at 3 months and was stable through the 12-month interval. Keratometric astigmatism showed a 1.40-diopter (D) reduction and the power of ectasia apex decreased from 82.00 D to 78.00 D. CONCLUSIONS: Corneal collagen CXL was a safe tool in the management of PMD, improving some parameters in advanced stages of the disease.