Efficacy of biodegradable collagen matrix (Ologen ® CM) in augmenting the success rate of Ahmed glaucoma valve implantation in canine glaucoma.

Objective: To prospectively assess the efficacy of a biodegradable collagen matrix (ologen) in dogs with uncontrolled glaucoma receiving an Ahmed glaucoma valve (AGV) implant.
Animal Studied: Five client-owned dogs with glaucoma (five eyes).
Procedures: Five eyes treated for uncontrolled glaucoma underwent AGV implantation with ologen. Ologen was placed on the AGV plate and tube with a scleral flap. Complete ophthalmological examinations were performed preoperatively and at 1 and 3 days, 1 and 2 weeks, and 1, 2, 3, and 6 months postoperatively. Surgical outcomes were assessed based on the intraocular pressure (IOP), vision, frequency of anti-glaucoma eye drops, and bleb morphology; complications, if any, were recorded. The number of dogs with an IOP <20 mmHg with or without topical medications were tabulated and compared to those with an IOP ≥20 mmHg or those requiring surgery to maintain the IOP at <20 mmHg.
Results: The IOP significantly decreased from 47.00 ± 5.09 mmHg preoperatively to 17.00 ± 0.71 mmHg 6 months postoperatively (p = .008). IOP was controlled (<20 mmHg) in 5/5 dogs at 6 months postoperatively. Brief periods of elevated IOP (IOP ≥ 20 mmHg, IOP spike) occurred in one eye (case 5) at 1 month (35 mmHg) and 2 months (33 mmHg) postoperatively. The anti-glaucoma eye drop frequency decreased from 3.2 ± 0.44 preoperatively to 1.6 ± 0.90 at 6 months postoperatively (p = .007).
Conclusions: To our knowledge, this is the first study to assess the potential safety of AGV implantation with ologen for canine glaucoma. This method effectively controlled the IOP, without any adverse effects.
(© 2021 American College of Veterinary Ophthalmologists.)