Evaluation of accelerated collagen cross-linking for the treatment of melting keratitis in eight dogs

Abstract

Objective: Melting keratitis is serious condition presenting a high risk of permanent blindness and is caused by infectious or noninfectious factors. In humans, the clinical efficacy of collagen cross-linking (CXL) has been described in the treatment of refractory infectious keratitis by arresting keratomalacia. The aim of this study was to evaluate the efficacy of accelerated CXL for the treatment of melting keratitis in dogs.

Animal studied and procedure: Eight dogs were treated for unilateral melting keratitis by accelerated CXL. Corneas were irradiated by UVA (370 nm) at 30 mW/cm² irradiance for 3 min after soaking by 0.1% riboflavin in 20% dextran for 30 min. Follow-up was conducted 3, 7, 14, and 30 days after treatment.

Results: Pain improvement was observed for all cases within 3 days after treatment. Epithelial healing was observed within 15 days for all cases. Disappearance of cellular infiltration was observed for all cases at day 7. The corneal vascularization disappeared for 4 of 8 dogs and was reduced for 4 of 8 dogs within 1 month. At 1 month, all cases presented a variable degree of corneal scarring, but all eyes had visual function. No recurrent infection was observed.

Conclusions: The main observation of this study is that all the cases have presented with the same clinical result regardless of the presence and the sensitivity of the infectious agents and regardless of the duration of the condition prior to CXL treatment. Accelerated CXL appears to be a valuable option for the treatment of melting keratitis.

Keywords: accelerated CXL; cross-linking; dogs; melting keratitis; optical coherence tomography; riboflavin.