Ocular and orbital blood flow in patients with essential hypertension treated with trandolapril

To study the effect of essential hypertension on flow velocity in the central retinal (CRA) and posterior ciliary arteries (PCA). Flow velocity was also evaluated in these arteries in patients with hypertension treated with trandolapril, an oral angiotensin-converting enzyme inhibitor.

Using the duplex scanner, flow velocity of the CRA and PCA was measured in 12 medication-free patients with hypertension and 10 normal controls. The hypertensive patients were then treated with oral trandolapril, 1 mg/day for 1 week. After 1 week of treatment, flow velocity was again measured in the arteries of the patients with hypertension.

There was a significant reduction in systolic and diastolic flow velocity of the vessels tested in the medication-free hypertensive patients when compared with those in the normal controls. In controls, the CRA had a peak systolic flow velocity (PSFV) of 34 cm/sec and an end diastolic flow velocity (EDFV) of 14 cm/sec; the PCA had a PSFV of 38 cm/sec and an EDFV of 16 cm/sec. In the hypertensive patients off medication, the CRA had a PSFV of 16 cm/sec and an EDFV of 6 cm/sec; the PCA had a PSFV of 17 cm/sec and an EDFV of 5 cm/sec. The diastolic component also was significantly decreased in the patients with hypertension. Flow velocity significantly increased in the hypertensive patients treated with trandolapril for 1 week, but did not reach the level of flow measured in normal controls.

The decreased flow velocity in hypertensive patients may result from a peripheral vasospasm in the vessels of the eye and orbit. This decreased flow velocity may be important in eyes that already have ocular disease. Improvement in flow velocity was noted with oral trandolapril but it did not reach the levels seen in normal controls.