Evaluation of retinal microcirculation in hypertensive patients with obstructive sleep apnea: a subgroup analysis...

This study aimed to investigate the impact of obstructive sleep apnea syndrome (OSAS) severity on retinal microvascular alterations in hypertensive individuals and to determine whether the presence of asymptomatic organ damage (AOD) further modulates these ocular changes.

A total of 102 hypertensive participants who underwent overnight polysomnography were classified into three groups based on the apnea-hypopnea index (AHI): non-OSAS (n=34), mild OSAS (n=36), and moderate-severe OSAS (n=32). All subjects underwent optical coherence tomography angiography (OCTA) to evaluate foveal superficial and deep capillary densities (FovSupMVD, FovDepMVD), foveal avascular zone (FAZ), and choroidal thickness. Among OSAS patients, AOD status was determined based on left ventricular mass index, carotid intima-media thickness, and microalbuminuria. Comparative and correlation analyses were performed to assess the influence of OSAS severity and AOD presence on retinal microcirculatory parameters.

A significant reduction in both FovSupMVD and FovDepMVD was observed with increasing OSAS severity (p = 0.001 and p < 0.001, respectively), while FAZ size remained unchanged. Although overall retinal thickness parameters were largely similar among groups, RTn differed significantly between groups (p = 0.044). Interestingly, temporal and nasal choroidal thickness increased significantly in the moderate-severe OSAS group (p = 0.006 and p = 0.005). Although AOD was associated with higher systemic vascular markers (e.g., carotid thickness, LVMI, microalbuminuria), OCTA parameters did not differ significantly between AOD-positive and AOD-negative patients (all p > 0.05). No significant interaction was found between OSAS severity and AOD on OCTA measures.

Retinal microvascular impairment in hypertensive OSAS patients was found to be strongly associated with OSAS severity, whereas the presence of AOD did not appear to contribute additional effects. These findings suggest that chronic intermittent hypoxia inherent to OSAS may play a primary role in retinal microvascular disruption. Retinal vessel density may have potential as a non-invasive biomarker of microvascular dysfunction in hypertensive patients with OSAS.