Effect of oral felodipine on ocular circulation

To evaluate the effects of felodipine, a calcium channel blocker, on ocular circulation.

In a double blind, randomized, crossover design, 10 volunteers received placebo or felodipine on 2 separate days. Bidirectional laser Doppler velocimetry (BLDV), laser Doppler flowmetry (LDF), and monochromatic fundus photography (MFP) were employed to assess retinal, choroidal, and optic nerve rim circulatory parameters. Measurements were obtained at baseline, 1.5, and 3 hours after dosing. Blood pressure, intraocular pressure (IOP), and heart rate were monitored, and perfusion pressure (PP) was calculated.

In comparison to placebo, significant average percentage decreases in diastolic blood pressure (BPd; p = 0.001), mean blood pressure (BPm; p = 0.003), and perfusion pressure (PP; p = 0.003) were observed 1.5 hours following felodipine. No significant differences were observed following placebo. Retinal, choroidal and optic nerve rim circulatory parameters showed no significant changes after placebo or felodipine. A significant positive correlation between BPd and optic nerve velocity (ONve1) was observed 3 hours following felodipine (R = +0.654; p = 0.040). In contrast, no significant correlation between BPd and ONve1 was noted (R = +0.198; p = 0.583) following placebo.

No significant change in retinal, optic nerve rim, or foveolar choroidal blood flow were observed, a factor that may be important in the treatment of systemic hypertension in patients with glaucoma.