Corneal grafting for the treatment of full-thickness corneal defects in dogs: a review of 50 cases

Objective To describe corneal grafting for the treatment of full-thickness corneal defects in dogs and to determine its effectiveness in preserving vision. Methods A review of the medical records of dogs that underwent corneal grafting following corneal perforations (≥3 mm) at the VTH-UAB from 2002 to 2012 was carried out. Results Fifty dogs of different breed, age and gender were included. Brachycephalic breeds were overrepresented (37/50;74%). All cases were unilateral, with euryblepharon being the most common concurrent ocular abnormality (20/50;40%). Full-thickness penetrating keratoplasties (FTPK) were performed in 21/50 eyes (42%) and lamellar keratoplasties (LK) in 29/50 eyes (58%). Frozen grafts (FroG) were used in 43/50 eyes (86%) and fresh homologous grafts (FreHoG) in 7/50 (14%). Of the former group, 26 were homologous (FroHoG:60%) and 17 heterologous (FroHeG:40%). A combination of topical medication (antibiotics, corticosteroids, cycloplegics, and 0.2% cyclosporine A) and systemic mycophenolate mofetil was administered. Median follow-up time was 200 days. Postsurgical complications included wound dehiscence (6/50;12%) and glaucoma (4/50;8%). Clinical signs of graft rejection were diagnosed as follows: FroHoG (13/26;50%), FroHeG (11/17;65%), FreHoG (4/7;57%), FTPK (12/21;57%), and LK (16/29;55%). Medical treatment successfully controlled graft rejection in 11/28 eyes (39%). Good anatomical outcome was achieved in 86% (43/50), of which 95% (41/43) were visual at last examination, with moderate opacification to complete transparency of the graft present in 48.2%. Conclusions Corneal grafting is an effective surgical treatment for full-thickness corneal defects in dogs. If graft rejection is present, additional medical or surgical therapy may be necessary, achieving a highly satisfactory visual outcome.