Intraocular pressure and ocular hemodynamics in patients with primary open-angle glaucoma treated with the combination of morning dosing of bimatoprost and dorzolamide hydrochloride

Aims: This prospective, multicenter, single-masked study evaluated the additive effect of dorzolamide hydrochloride 2% on the diurnal intraocular pressure (IOP) curve and retinal and retrobulbar hemodynamics in patients with primary open-angle glaucoma (POAG) treated with morning-dosed bimatoprost 0.03%. Methods: Eighty-nine patients (aged, 60.7 ± 11.8 years, range 33-80; 68 women) with POAG received bimatoprost dosed once in the morning for 1 month, after which dorzolamide was added twice daily for 2 months. IOP (Goldmann) and arterial blood pressure (BP) and diurnal ocular perfusion pressures (OPP) were measured every 2 hr for 24 hr. Heidelberg retina flowmetry of the retinal microcirculation was recorded four times daily in 64 patients and colour Doppler imaging of the ophthalmic and central retinal arteries was recorded five times daily in 25 patients. All measurements were taken after the two phases of treatment and compared using anova analysis with Bonferroni adjustment. Results: Mean baseline IOP was 16.5 ± 3.4 mmHg. Mean diurnal IOP with dorzolamide adjunctive therapy (12.9 ± 2.1 mmHg) was significantly lower compared to mean IOP with bimatoprost monotherapy (13.6 ± 2.2 mmHg) (p = 0.03). Adjunctive dorzolamide therapy significantly decreased vascular resistance in the ophthalmic artery (p = 0.02). Mean diastolic BP and OPP were significantly lower after adjunctive therapy. There were no changes in retinal microcirculation between the two phases of treatment. Conclusions: Adjunctive dorzolamide therapy to morning-dosed bimatoprost 0.03% reduced diurnal IOP and vascular resistance in the ophthalmic artery but did not alter retinal circulation in this group of patients with POAG.