The One-Month Effects of Topical Betaxolol, Dorzolamide and Apraclonidine on Ocular Blood Flow Velocities in Patients with Newly Diagnosed Primary Open-Angle Glaucoma

Abstract

Purpose: This double-masked, prospective and randomized clinical trial was planned to investigate with color Doppler imaging the 1-month vascular effects 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 were enrolled in this study. All patients were newly diagnosed cases and had not received any antiglaucoma medication before. Patients who had a systemic vascular disease (including systemic hypertension) or were taking β-blockers, 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 with topical betaxolol, group B patients received topical dorzolamide eye drops, and group C patients were treated with topical apraclonidine eye drops. Peak systolic velocities (PSV), end-diastolic velocities (EDV) and resistive indices (RI) in the right ophthalmic arteries (OA), central retinal arteries (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 treatment, the same measurements were repeated. The inter- and intragroup results were compared statistically. Results: Compared to pretreatment measurements, topical betaxolol therapy significantly decreased PSV only in the PCA and only on day 30 of treatment (p = 0.011). On days 15 and 30, dorzolamide decreased 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 compared between the groups, PSV in the OA were significantly higher in dorzolamide-treated patients compared to other groups (p = 0.01 and p = 0.011). On day 30 of treatment, PSV in the OA was also higher in the dorzolamide-treated group than the other groups (p = 0.012 and p = 0.01). Additionally, apraclonidine-treated patients had a significantly lower EDV in the OA than the other groups (p = 0.013 and p = 0.01). The RI in the OA was also significantly lower in the apraclonidine-treated group compared to the other groups (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 retrobulbar arterial circulation of POAG patients. Betaxolol seems superior to apraclonidine in this regard. Our data may help the clinician when treating patients with POAG medically. Further studies using a larger population size may clarify our results.

Volumetric colour Doppler imaging: a useful tool for the determination of ocular blood flow in glaucoma patients?

“…Regarding dorzolamide, positive effects on ocular haemodynamics are reported. [13][14][15] With the results from the present study, we were able to reproduce the previously described accelerating effects of dorzolamide on ocular blood flow and reduction of resistance in the SPCA, but, in contrast, could not determine a change in vCDI readings. This is a further indicator that vCDI in its present form is not applicable for use as a clinical diagnostic tool or for scientific purposes.…”

“…(4) Finally, in 15 patients, the capacity of the method to identify changes of ocular perfusion was tested by topically applying dorzolamide, an inhibitor of the carbonic anhydrase, which has been shown to increase ocular perfusion in glaucoma patients. [13][14][15] The study was performed under blinded conditions. Thus, evaluation of all four steps of the study was performed after completion of the entire data collection.…”

A Comparison of the Long-Term Effects of Dorzolamide 2% and Brinzolamide 1%, Each Added to Timolol 0.5%, on Retrobulbar Hemodynamics and Intraocular Pressure in Open-Angle Glaucoma Patients

“…[15][16][17][18][19][20] However, not all studies have reported a positive outcome. [21][22][23] Relatively few studies have evaluated the effect of topical brinzolamide upon OBF in glaucoma patients.…”

Comparative Analysis of the Effects of Brimonidine and Dorzolamide on Ocular Blood Flow Velocity in Patients with Newly Diagnosed Primary Open-Angle Glaucoma

“…24 Some studies showed that dorzolamide provides an improvement in optic nerve head and retinal hemodynamics in patients with normal-tension glaucoma or newly diagnosed POAG. 15,[25][26][27] In contrast, this study showed no significant flow changes in the retrobulbar vessels of patients after 3 months of dorzolamide treatment.…”