Background: The purpose of this study was to assess the role of arterial hypotension in the pathogenesis of certain types of glaucoma. Methods: We compared diurnal and nocturnal fluctuations in blood pressure by using an ambulatory recording over a 24-h period in two different groups of patients: one of 16 patients with focal ischemic glaucoma (FIG) and another of 16 patients with primary open angle glaucoma (POAG). Results: In patients with FIG, compared to those with POAG, we found: lower diastolic blood pressure (BP; 75.7 vs 82.5 mmHg, P < 0.05), systolic BP (121.7 vs 131.2 mmHg, P < 0.05) and mean BP (90.5 vs 101.5 mmHg, P < 0.05) over 24 h; lower diurnal diastolic BP (78.1 vs 85.5 mmHg, P < 0.05), and systolic BP (124.6 vs 134.2 mmHg, P < 0.05); greater nocturnal systolic BP variability (8.2% vs 6.2%, P < 0.05); and a greater percentage of diurnal low readings (14.53% vs 2.8%, P < 0.05), compared with the literature limits (101/61 mmHg). However, the number of nocturnal low readings was not different for either group. Conclusion: It is important to detect arterial hypotension - one of the components of the vascular factor - during examination of a patient with normal-pressure glaucoma. This is one element in preserving the best possible perfusion of the optic nerve.
