Microvascular Changes in Primary Open-Angle Glaucoma Associated with Hypertension: A Prospective OCT-Angiography Analysis

Abstract

Background: Primary open-angle glaucoma (POAG) is a progressive optic neuropathy associated with visual field loss and optic disc cupping. Although elevated intraocular pressure is the primary risk factor, the contribution of systemic arterial hypertension (HTN) remains uncertain. Optical coherence tomography angiography (OCT-A) enables non-invasive evaluation of retinal and peripapillary microvasculature. This study investigated the association between systemic hypertension and microvascular alterations in POAG using OCT-A. Methods: This prospective observational cohort study was conducted in a tertiary eye care setting and included 40 eyes from 40 adults with confirmed POAG receiving topical anti-glaucoma therapy. Participants were grouped as hypertensive (n=20) or normotensive (n=20). OCT-A imaging was performed using the Cirrus 5000 HD-OCT with Angioplex. Macular and peripapillary vessel density of the superficial and deep retinal capillary plexuses was quantified from 6×6 mm scans. Only high-quality images (signal strength ≥7/10, no motion or segmentation artifacts) were analyzed to minimize measurement bias. Additional assessments included visual field testing, retinal nerve fiber layer thickness, and cup-to-disc ratio. Group comparisons and correlation analyses were performed, with statistical significance set at p<0.05. Results: Hypertensive POAG patients demonstrated significantly lower macular and peripapillary vessel density compared with normotensive patients (p<0.05). In the hypertensive group, reduced vessel density was associated with progressive visual field deterioration and increased cup-to-disc ratio. These associations were less pronounced among normotensive patients. Conclusion: Systemic hypertension is associated with greater microvascular compromise in POAG, supporting a vascular contribution to glaucoma progression and highlighting the importance of blood pressure control in glaucoma management.