Effect of Adjuvant Topical Dorzolamide-Timolol vs Placebo in Neovascular Age-Related Macular Degeneration: A Randomized Clinical Trial

Importance Some eyes with neovascular age-related macular degeneration (AMD) have persistent exudation despite frequent intravitreal anti–vascular endothelial growth factor (VEGF) injections. Adjuvant therapies that further reduce edema may improve vision outcomes. Objective To compare the short-term effect of topical dorzolamide-timolol vs placebo in eyes with neovascular AMD that have persistent exudation following intravitreal anti-VEGF injections. Design, Setting, and Participants Randomized placebo-controlled clinical trial with enrollment from March 1, 2017, through October 30, 2018. Multicenter trial at 4 clinical sites in the United States. Sixty-three patients with neovascular AMD who had persistent exudation despite intravitreal anti-VEGF injections at 4-week, 5-week, or 6-week intervals. Interventions Patients were randomized to use dorzolamide-timolol or artificial tears for the study duration. They continued to receive the same anti-VEGF drug at the same interval as the 2 visits before enrollment for 3 additional study visits. Main Outcomes and Measures The primary outcome measure was change in mean central subfield thickness on optical coherence tomography from baseline to visit 3 (approximately 3 months). Secondary measures included change in mean maximum subretinal fluid height, mean maximum pigment epithelial detachment height, and mean visual acuity (VA). Results This trial included 52 patients. All 27 patients (100%) assigned to dorzolamide-timolol and 23 of 25 (92%) assigned to placebo were analyzed for the primary outcome. Mean (SD) age was 78.4 (7) years, and 34 of 50 patients (68%) were women. Mean (SD) injections were 20.5 (14) (range, 4-58) before enrollment. Mean (SD) baseline logMAR VA was 0.361 (0.26) (approximate Snellen equivalent, 20/50). Comparing the dorzolamide-timolol with placebo group from baseline to visit 3, mean (SD) change in central subfield thickness (primary outcome) was −36.6 (54) μm vs 1.7 (52.3) μm (difference, 30.8; 95% CI, 0.3-61.3;P = .04); secondary outcomes: maximum PED height was −39.1 (65) μm vs 1.1 (16) μm (difference, 39.6; 95% CI, 9.6-69.6;P = .01) and change in VA from baseline to visit 3 was −2.3 (5) vs 0.3 (1) letters (difference, 2.6 letters; 95% CI, −1.9 to 7.1 letters;P = .78). Conclusions and Relevance These findings suggest use of dorzolamide-timolol in patients with neovascular AMD with persistent exudation resulted in anatomic but not visual acuity improvements compared with placebo at approximately 3 months. Additional clinical trials with longer follow-up and larger sample sizes presumably would be needed to determine the role, if any, of dorzolamide-timolol in neovascular AMD. Trial Registration ClinicalTrials.gov Identifier:NCT03034772