Central Blood Pressure, Arterial Waveform Analysis, and Vascular Risk Factors in Glaucoma

Abstract

Reduced ocular perfusion pressure has been linked to glaucoma, and increased arterial stiffness is implicated in systemic cardiovascular risk. This study measured central blood pressure (BP) and arterial waveforms derived from pulse tonometry, together with data on systemic and ocular vascular factors relevant to glaucoma status. A total of 126 patients and 66 normal controls were tested, including 90 primary open-angle glaucoma (POAG) patients and 36 normal tension glaucoma (NTG) patients. Glaucoma patients had been followed for at least 3 years and inclusion required several (>4) reliable visual fields such that glaucoma progression could be determined. Radial pulse tonometry and brachial BP data were collected, together with data on disc hemorrhages, spontaneous venous pulsation, peripapillary atrophy, smoking, and medications. Brachial BP or derived central aortic BP parameters generally showed no significant differences between glaucoma patients and normal individuals. The POAG group had a lower pulse pressure, which was also significant in the regression analysis (P<0.002). In the arterial waveform analysis, POAG was associated with a lower brachial form factor than NTG (P<0.001) and higher subendocardial viability ratio (P<0.008). NTG was associated with a lower body mass index, and POAG with a smoking history. There was an increased incidence of disc hemorrhages and a reduced incidence of spontaneous venous pulsations in the progressing group. Derived central BP does not reveal significant differences from controls or in glaucoma subgroups, but a reduced pulse pressure was identified. There may be some changes in arterial pulse waveform shape suggesting possible differences in diastolic perfusion. Disc hemorrhages and loss of spontaneous venous pulsation were associated with disease progression.