Accelerated corneal cross-linking treats bullous keratopathy in dogs

Abstract

OBJECTIVE: Bullous keratopathy (BK) is a serious corneal condition leading to impaired vision and ocular pain, due to chronic corneal edema and recurrent superficial ulceration. BK is refractory to conventional therapy. In human patients, corneal collagen cross-linking (CXL) has been used for the treatment of BK, and CXL treatment was recently described for canine patients. The aim of this study was to evaluate the clinical and pachymetric effects of accelerated CXL in dogs affected by BK. ANIMAL STUDIED: Eight dogs (10 eyes) with BK underwent accelerated CXL. PROCEDURES: CXL treatment comprised 30 min of riboflavin-dextran instillation, followed by 3 min of UVA irradiation at 30 mW/cm². Ocular pain, corneal edema, corneal ulceration, and pachymetry were evaluated 7, 14, 30, 90, and 180 days after treatment. RESULTS: Corneal ulceration and ocular pain were resolved by 1 week after CXL treatment and did not recur during the 6-month follow-up period. Corneal edema improved in the first 3 months, but worsened from months 3 to 6. Corneal thickness initially decreased, but returned to baseline by 6 months post-CXL. CONCLUSIONS: CXL is a useful treatment option for BK in dogs, despite the short-lasting effects on corneal thickness. Patient comfort improved rapidly after a single procedure, although CXL did not achieve resolution of corneal edema. Treatment protocols may be refined to produce more durable effects on corneal edema.