Recurrent peripheral stromal keratitis following corneal collagen cross-linking: A case report

Corneal collagen cross-linking (CXL) has become the standard initial intervention in eyes with progressive keratoconus (KC) that have not undergone keratoplasty. The prolonged exposure of the de-epithelialized cornea predisposes it to adverse complications, such as microbial keratitis and melting. Herein, we report a case of bilateral recurrent peripheral stromal keratitis following CXL. We present a 29-year-old woman who complained of ocular redness and discomfort in both eyes for 4 months, and had undergone bilateral CXL 10 months before. The best spectacle corrected visual acuity (BSCVA) was 60/200 in the right and 80/200 in the left eye. Both eyes showed moderate conjunctival hyperemia, dilation, and engorgement of the perilimbal episcleral vessels. There was a peripheral corneal stromal infiltration with thinning, and an overlying epithelial defect in the right eye with a lucid interval from the limbus. She was treated with lubricating eye drops and ointments and topical corticosteroids every 4 hours for 2 weeks then slowly tapered off. Afterwards, she experienced multiple recurrences in both eyes, which were successfully managed with topical corticosteroids and lubricants. After 2 years, her BSCVA was 20/30 with −3.00-5.50 * 90 in the right eye and 20/40 with −4.00-4.50 * 90 in the left. Although CXL is a safe method, studies with longer follow-ups are needed to investigate the risk of rare complications.