Effect of Long-term Topical Application of 0.005% Latanoprost on Intraocular Pressure Uncontrolled by Multiple or Single Drug Therapy in Dogs with Secondary Glaucoma

Purpose: To evaluate the effect of long-term topical application of 0.005% latanoprost on intraocular pressure (IOP) uncontrolled by multiple or single drug therapy in dogs with secondary glaucoma. Animals Studied: Twenty-seven dogs with secondary glaucoma. Procedure: Baseline IOP was measured before the start of 0.005% latanoprost therapy. The iridocorneal angle (ICA) was measured and graded as open, slightly narrow, narrow or closed. The effect of 0.005% latanoprost on IOP was followed for a minimum of two months. Dogs were classified as responders if IOP decreased with treatment or as non-responders if there was no change in IOP. Results: IOP did not decrease in three dogs (11%). It decreased initially but subsequently increased over time in 21 dogs (78%). IOP remained <25 mmHg for more than 60 months in 3 dogs (11%). No correlation between ICA grade and IOP reduction from baseline was observed. Conclusions: Topical application of 0.005% latanoprost resulted in long-term control of IOP in 11% of the dogs. The remaining dogs showed either no response or just a temporary decrease in IOP with topical 0.005% latanoprost treatment.