Effect of prophylactic dorzolamide-timolol on intraocular pressure spikes following phacoemulsification

OBJECTIVE: To evaluate the use of fixed-combination, dorzolamide-timolol prophylaxis in controlling intraocular pressure (IOP) following phacoemulsification surgery, while controlling for glaucomatous status. DESIGN: A retrospective chart review. PARTICIPANTS: A total of 558 patients undergoing phacoemulsification between September 5, 2023, and April 15, 2024, performed by a single surgeon. Only the first operated eye was included for bilateral surgeries, with 519 eyes analyzed in the study. METHODS: Patients were divided on the basis of a change in practice that occurred on December 31, 2023; all control eyes were obtained between January 1 and April 15, 2024, whereas all intervention eyes were obtained prior to this period. The control group received no prophylaxis (n = 233), and the intervention group received Cosopt immediately postoperatively (n = 286). Preoperative and postoperative day 1 (POD1) IOPs were measured using the iCare IC-100 tonometer. IOP readings ≥28 mm Hg were considered elevation spikes. Mean IOPs and spike incidences were statistically compared. RESULTS: Mean preoperative IOPs were identical (14.4 ± 3.1 mm Hg; p = 0.511). Mean POD1 IOP was significantly lower in the Cosopt group (13.7 ± 5.0 vs 18.4 ± 6.4 mm Hg; p < 0.0001). POD1 IOP spikes were less frequent in the Cosopt group (1.7% vs 9.9%; p < 0.0001). Cosopt was effective independent of glaucoma comorbidities (OR: 0.15; 95% CI: 0.06-0.42; p < 0.0002). Open-angle glaucoma and ocular hypertension (analyzed as a group: OR: 6.08; 95% CI: 1.72-21.54; p = 0.005) and narrow angles (OR: 6.54; 95% CI: 1.16-36.79; p = 0.03) were independent risk factors for IOP spikes. CONCLUSIONS: Prophylactic dorzolamide-timolol reduces mean postoperative IOP and POD1 pressure spikes, independent of glaucoma comorbidities.