The one-month effects of topical betaxolol, dorzolamide and apraclonidine on ocular blood flow velocities in patients with newly diagnosed primary open-angle glaucoma

Purpose: This double-masked, prospective and randomized clinical trial was planned to investigate with color Doppler imaging the 1-month vascular effe cts of betaxolol, dorzolamide and apraclonidine treatment on patients with newly diagnosed primary open-angle glaucoma (POAG). Methods: 22 consecutive patients with newly diagnosed POAG between the ages of 46 and 72 years wer e enrolled in this study. All patients were newly diagnosed cases and had n ot received any antiglaucoma medication before. Patients who had a systemic vascular disease (including systemic hypertension) or were taking P-blocke rs, nitrates or calcium channel blockers were excluded from the study. The patients were randomly divided into three groups. Groups A and B contained 7 patients, group C contained 8 patients. Group A patients were treated wit h topical betaxolol, group B patients received topical dorzolamide eye drop s, and group C patients were treated with topical apraclonidine eye drops. Peak systolic velocities (PSV), end-diastolic velocities (EDV) and resistiv e indices (RI) in the right ophthalmic arteries (OA), central retinal arter ies (CRA) and posterior ciliary arteries (PCA) were measured at baseline by using color Doppler imaging on a masked basis. On days 15 and 30 of treatm ent, the same measurements were repeated. The inter- and intragroup results were compared statistically. Results: Compared to pretreatment measurement s, topical betaxolol therapy significantly decreased PSV only in the PCA an d only on day 30 of treatment (p = 0.011). On days 15 and 30, dorzolamide d ecreased RI measurements in the PCA compared to pretreatment measurement (p = 0.013 and p = 0.011, respectively). Apraclonidine also decreased PSV in the OA on days 15 and 30 of treatment when compared to pretreatment values (p = 0.013 and p = 0.012, respectively). When 15-day measurements were comp ared between the groups, PSV in the CA were significantly higher in dorzola mide-treated patients compared to other groups (p = 0.013 and p = 0.011). O n day 30 of treatment, PSV in the OA was also higher in the dorzolamide-tre ated group than the other groups (p = 0.012 and p = 0.01). Additionally, ap raclonidine-treated patients had a significantly lower EDV in the OA than t he other groups (p = 0.013 and p = 0.01). The RI in the OA was also signifi cantly lower in the apraclonidine-treated group compared to the other group s (p = 0.01 and p = 0.011). Conclusion: Our study suggests that dorzolamide has the most advantageous 1-month effects on blood flow velocity in the re trobulbar arterial circulation of POAG patients. Betaxolol seems superior t o apraclonidine in this regard. Our data may help the clinician when treati ng patients with POAG medically. Further studies using a larger population size may clarify our results. Copyright (C) 2001 S. Karger AG, Basel.