Retinal microvascular impairment in hypertensive OSAS patients was found to be strongly associated with OSAS severity, whereas the presence of asymptomatic organ damage did not appear to contribute additional effects.
Key Findings
Results
Foveal superficial and deep capillary densities significantly decreased with increasing OSAS severity in hypertensive patients.
102 hypertensive participants were classified into non-OSAS (n=34), mild OSAS (n=36), and moderate-severe OSAS (n=32) groups based on apnea-hypopnea index (AHI)
Foveal superficial microvascular density (FovSupMVD) reduction was significant at p=0.001
Foveal deep microvascular density (FovDepMVD) reduction was significant at p<0.001
All subjects underwent optical coherence tomography angiography (OCTA) to evaluate these parameters
Results
Foveal avascular zone (FAZ) size remained unchanged across OSAS severity groups.
FAZ was measured via OCTA in all three groups
No statistically significant difference in FAZ size was found among non-OSAS, mild OSAS, and moderate-severe OSAS groups
This finding contrasts with the significant changes observed in capillary density measures
Results
Temporal and nasal choroidal thickness increased significantly in the moderate-severe OSAS group.
Temporal choroidal thickness difference was significant at p=0.006
Nasal choroidal thickness difference was significant at p=0.005
This increase was specific to the moderate-severe OSAS group compared to other groups
Overall retinal thickness parameters were largely similar among groups, though RTn differed significantly between groups (p=0.044)
Results
Asymptomatic organ damage (AOD) was associated with higher systemic vascular markers but did not significantly affect OCTA parameters.
AOD status was determined based on left ventricular mass index (LVMI), carotid intima-media thickness, and microalbuminuria
AOD-positive patients showed higher systemic vascular markers including carotid thickness, LVMI, and microalbuminuria
All OCTA parameters showed no significant difference between AOD-positive and AOD-negative patients (all p>0.05)
No significant interaction was found between OSAS severity and AOD on OCTA measures
Conclusions
OSAS severity, rather than asymptomatic organ damage, was identified as the primary driver of retinal microvascular disruption in hypertensive patients.
Chronic intermittent hypoxia inherent to OSAS was suggested to play a primary role in retinal microvascular disruption
AOD presence did not appear to contribute additional effects beyond those attributable to OSAS severity alone
The authors suggest retinal vessel density may have potential as a non-invasive biomarker of microvascular dysfunction in hypertensive patients with OSAS
What This Means
This research suggests that the severity of obstructive sleep apnea (OSA) — a condition where breathing repeatedly stops during sleep — has a meaningful impact on the tiny blood vessels in the retina (the light-sensitive layer at the back of the eye) of people who also have high blood pressure. Using a specialized imaging technique called optical coherence tomography angiography (OCTA), researchers found that as OSA became more severe, the density of blood vessels in the central part of the retina decreased. Additionally, patients with moderate-to-severe OSA showed increased thickness of the choroid, a layer of blood vessels beneath the retina. These changes were detected even though the size of the foveal avascular zone — a small central area normally free of blood vessels — stayed the same across all groups.
Interestingly, the study also looked at whether having signs of silent organ damage (such as thickening of artery walls, an enlarged heart muscle, or protein in the urine) made these eye changes worse. Despite these markers indicating broader cardiovascular stress, they did not appear to further worsen the retinal blood vessel changes seen on imaging. This suggests that the repeated drops in oxygen levels caused by OSA itself — rather than accumulated damage to other organs — may be the main factor harming the retinal microvasculature.
This research matters because it points to OCTA-based retinal imaging as a potentially useful, non-invasive way to detect early microvascular problems in people with both high blood pressure and OSA. It also highlights that treating OSA may be important for protecting eye health, even before more obvious organ damage becomes apparent.
Toprak G, Bayraktar M, Öğün M, Sezer T, Meydan B. (2026). Evaluation of retinal microcirculation in hypertensive patients with obstructive sleep apnea: a subgroup analysis based on asymptomatic organ damage.. International ophthalmology. https://doi.org/10.1007/s10792-026-04270-w