Endothelial failure after collagen cross-linking with riboflavin and UV-A: case report with literature review.

To report a case of endothelial decompensation after a collagen cross-linking (CXL) procedure for keratoconus. An 18-year-old boy had CXL for keratoconus in the right eye. He developed keratouveitis with generalized corneal edema seen 3 weeks after the procedure. Polymerase chain reaction for aqueous humor Herpes simplex virus was negative. The patient was treated with topical steroids. Specular microscopy revealed mildly reduced density of endothelial cells. On follow-up to 6 months, corneal edema increased with the formation of epithelial bullae. Penetrating keratoplasty was performed. Possible causes for this complication are discussed. Clinical and histopathological analyses revealed generalized loss of endothelial cells along with signs of inflammation. Although it is considered very safe, collagen CXL can cause severe keratouveitis and endothelial failure.