Feline ocular tumors following ciliary body ablation with intravitreal gentamicin

Practitioners approach chemical ciliary body ablation (CBA) in cats with caution. In 1994, an academic letter proposed a potential link between intraocular gentamicin injections for glaucoma and the appearance of ocular tumors in cats (Veterinary and Comparative Ophthalmology, 4, 1994, 166). There is an historic perceived risk for the development of feline ocular post-traumatic sarcoma following gentamicin ciliary body ablation, and many clinicians refrain from chemical ablation in cats for this reason. A recent study discussed the possibility of a correlation between intravitreal gentamicin and tumor promotion in dogs (Veterinary Ophthalmology, 16, 2013, 159). We searched the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) database for cases of cats diagnosed with ocular tumors following ciliary body ablation. Of eight cases with historic gentamicin injection, five had malignant tumors: three post-traumatic sarcomas and two melanomas.