Sterile Peripheral Corneal Infiltrates Following Corneal Cross-Linking For Early Keratoconus: A Case Report

To describe the clinical course, management, and outcome of bilateral sterile peripheral corneal infiltrates after corrneal collagen cross-linking (CXL) for early keratoconus, and to highlight the importance of differentiating this inflammatory complication from infectious keratitis.

Centro de Oftalmología Barraquer, department of cornea and refractive surgery, Barcelona, Spain. 

A 32-year-old patient with early bilateral keratoconus underwent CXL with 0.1% riboflavin and standard UVA irradiation under topical anesthesia. A bandage contact lens was placed postoperatively. Treatment included artificial tears, topical antibiotic, and topical NSAID. On postoperative day 4, the patient developed bilateral pain and decreased visual acuity. Slit-lamp examination showed peripheral dense stromal infiltrates with epithelial defects and mild corneal haze in both eyes; the anterior chamber was quiet. Corneal scrapings were obtained and cultures were negative. Intensive fortified topical antibiotics (hourly ceftazidime and tobramycin, plus nighttime tobramycin ointment) were started. After 72 hours, given negative cultures and suspicion of sterile inflammatory infiltrates, topical fluorometholone was added three times daily. Rapid regression of infiltrates followed corticosteroid initiation. Antibiotics were gradually tapered and discontinued, while corticosteroids were slowly reduced over several weeks. At 3-month follow-up, near-complete corneal transparency was observed with minimal residual peripheral stromal changes and good visual recovery.

Sterile peripheral infiltrates are an uncommon inflammatory complication after CXL, usually appearing within the first postoperative week. They are culture-negative and likely immune-mediated. Careful exclusion of infection is essential. Once infectious keratitis is ruled out, early corticosteroid therapy promotes rapid resolution and favorable visual outcomes, minimizing long-term sequelae.