Riboflavin and Ultraviolet A Collagen Crosslinking of the Cornea for the Treatment of Keratitis

Purpose: To describe riboflavin and ultraviolet light (UV) collagen crosslinking as an effective treatment for infectious keratitis. Methods: A 25-year-old previously healthy female contact lens user was diagnosed with unilateral severe keratitis with unclear pathogenesis, although the clinical presentation suggested acanthamoeba as the infectious agent. A 4-mm diameter, annular, semi-opaque infiltrate was found on the paracentral parts of the cornea in the left eye (OS). Laboratory examinations for bacteria, herpes simplex, and acanthamoeba were performed, but no specific pathogen could be detected. Best corrected visual acuity (BCVA) at presentation was 20/1000. Treatment was initialized with broad-spectrum antibiotics also covering acanthamoeba. During the first month of treatment the keratitis progressed and the corneal thickness diminished. Therefore, treatment with riboflavin and UV collagen crosslinking was initiated. Results: After riboflavin and UV collagen crosslinking therapy, there was a rapid decrease of pain and necrotic material. Reepithelialization of the cornea started within a few days and was complete within a month. After 2 months, the wound had healed completely. Nine months after the UV treatment, BCVA was 20/30. Conclusions: This case illustrates the positive effects of riboflavin and UV collagen crosslinking on presumed infectious keratitis with a satisfactory final visual outcome. This may be a promising new treatment for keratitis, although this remains to be elucidated in detail in future studies. Until more data are available this treatment should only be considered in therapy-refractive keratitis or ulceration and not in the first line of defence since it may have cytotoxic side effects.