[Arterial hypotension in glaucoma of normal or moderately high pressure]

Arterial hypotension, by decreasing blood flow in the optic nerve head, may be a risk factor for glaucomatous damage. The purpose of this study was to compare blood pressure in different types of glaucoma patients, using ambulatory recording.

An ambulatory blood pressure recording was performed in 55 glaucoma patients over a 24-hour period. Two groups of patients could have been differentiated according to pretreatment intra-ocular pressure level: a group of 38 patients (GPNM) with normal or moderately elevated intra-ocular pressure, and a group of 17 patients (GPH) with high intra-ocular pressure.

A statistically significant different lower blood pressure was found in group GPNM for: diastolic mean blood pressure (76.4 versus 81.4 mmmHg p = 0.05), diastolic nocturnal (71.8 versus 78.1 mmHg p = 0.025), and for some hourly intervals: from 2:00 to 3:00 (p = 0.008), 8:00 to 9:00 (p = 0.01) and 15:00 to 18:00 (p = 0.03). The mean lowest readings were lower (p < 0.05) in group GPNM (95.8/54.4 versus 102/59.9 mmHg). The percentage of low readings (9.9% versus 5.1% p = 0.01) and systolic drops (0.226 versus 0.192 p = 0.018) were also higher in this group.

Hypoperfusion of optic nerve head may be a significant factor in glaucomatous damage by compromising blood supply. It is important to identify arterial hypotension when examining of normal or moderately elevated pressure glaucoma patients, and ambulatory monitoring of blood pressure is currently the best test. These episodes should be taken into consideration, especially when initiating systemic antihypertensive therapy, in order to maintain, as well as possible, perfusion of the optic nerve head.