Clinical outcome of intravitreal gentamicin injection for the treatment of end-stage glaucoma in five rabbits (eight eyes)

Abstract

Background: Glaucoma is a painful and blinding condition that occurs in many species, including rabbits. When medication is no longer effective in  maintaining intraocular pressure (IOP), enucleation is the recognized treatment for rabbits with end-stage glaucoma. However, this procedure carries  risks relating to the procedure and the anesthesia.

Aim: The aim of this retrospective study was to report the efficacy of intravitreal gentamicin injection in controlling IOP in blind eyes of rabbits with end-  stage glaucoma. Ocular and non-ocular complications were retrospectively assessed.

Methods: Medical record review was performed to identify five client-owned rabbits (eight eyes) that were treated by intravitreal injection of 6–20 mg of  gentamicin per eye (median 7.18 mg/kg) for chronic, end-stage glaucoma. Treatment was unilateral in two and bilateral in three rabbits. IOP control was  assessed via rebound tonometry readings performed approximately 2 weeks, 1 month, 3 months, and 6 months after injection. Total follow-up was  between 313 and 1,111 days. Ocular complications were recorded and systemic health was estimated by the owner-answered questionnaire and changes  in body weight.

Results: IOP was <25 mmHg in 87.5% of eyes 3 months post-injection. The most common ocular complications were cataracts (62.5%), anterior uveitis (25%), retinal detachment (12.5%), and corneal erosion (12.5%). There were no behavioral or body weight changes suggestive of systemic complications.

Conclusion: 87.5% of rabbit eyes treated with intravitreal gentamicin had controlled IOP 3 months after injection. All eyes were blind at the time of injection. Ocular side effects were common. Investigation of the safety and systemic effects of intravitreal gentamicin injection is required; however, no overt complications were identified in treated rabbits in this study