Peripheral sterile corneal infiltrates and melting after collagen crosslinking for keratoconus.

Corneal collagen crosslinking (CCC)with riboflavin/ ultraviolet-A (UV-A) is a new therapeutic technique designed to strengthen the cornea and arrest progressive corneal ectasia. Few complications have been reported following this therapy. We report the case of a 40-year-old patient who had CCC for progressive keratectasia secondary to keratoconus. The patient had no medical history of systemic illness or ocular inflammatory disorders. Corneal collagen crosslinking was performed under topical anesthesia (proxymethacaine 0.5% without preservative). The central 8.0 mm of epithelium was mechanically debrided without trephination using a hockey stick blade. Riboflavin 0.1% in 20% dextran drops (Medio-Cross, IROC AG) were applied every 3 minutes for 30-minute exposure to UVA (365 nm, 3 mW/cm) using a dedicated UVA source (UV-X, IROC AG). Riboflavin 0.1% drops were applied every 5 minutes throughout the UV exposure period. A bandage contact lens was placed at the end of surgery. Postoperatively, chloramphenicol 0.3% 4 times daily, dexamethasone 0.1% drops 2 hourly (preservativefree), and cyclopentolate 1% drops twice daily were prescribed. Five days postoperatively, 3 peripheral areas of marginal infiltration without overlying epithelial ulceration were observed (Figure 1, A). The central epithelial defect had healed. A diagnosis of noninfective keratitis was made, and the patient was started on twice hourly preservative-free levofloxacin and dexamethasone 0.1%. Markers for rheumatoid factor, antineutrophilic cytoplasmic antibodies, immune complexes, erythrocyte sedimentation rate, and C-reactive protein were all negative. One week later, much of the marginal infiltration had disappeared leaving areas of peripheral stromal thinning, estimated at 40% to 50% of the total corneal thickness at the maximal point. A linear superior area of superficial infiltration remained (Figure 1, B). Topical steroids were increased to hourly prednisolone acetate 1%, and topical antibiotic agents were reduced to 4 times daily. In the subsequent weeks, there was complete resolution of infiltrates but with residual marginal thinning (maximum 30%) (Figure 1, B). The best corrected visual acuity had returned to 6/18 at the last examination, 2 months after the crosslinking procedure.