Retinal and Choroidal Changes in Obstructive Sleep Apnea Syndrome Assessed by Ultra- Widefield Swept-Source Optical Coherence Tomography Angiography

PURPOSE To investigate central and peripheral retinal and choroidal alterations using ultra-widefield swept-source optical coherence tomography angiography (UWF-SS-OCTA) in patients with obstructive sleep apnea syndrome (OSAS) stratified by disease severity. METHODS The study included patients with mild-moderate OSAS (n = 23 eyes), severe OSAS (n = 22 eyes), and healthy controls (n = 26 eyes). UWF- SS-OCTA scans centered on the fovea were used to divide the macula 8 concentric rings spanning from the central macula to the peripheral retina (0–21 mm). Vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), and choroidal thickness (CT) were analyzed across all rings. Correlations with apnea-hypopnea index (AHI) and lowest oxygen saturation (LSaO₂) were also assessed. RESULTS SCP vessel density was significantly reduced only in the far periphery (ring 8) across all OSAS groups. DCP impairment was more extensive, with severe OSAS patients showing significantly decreased vessel density in peripheral rings 5–8 versus controls (all p < 0.05), particularly in the superior and inferior quadrants (all p < 0.05). Choroidal thinning in severe OSAS followed a similar pattern, being significantly reduced in rings 4–8 (all p < 0.05), particularly in the superior, inferior, and nasal quadrants (all p < 0.05). DCP vessel density and choroidal thickness in peripheral regions correlated negatively with AHI and positively with LSaO₂. CONCLUSIONS For patients with OSAS, damage to the deep capillary plexus and choroid predominantly affects the peripheral retina and is significantly associated with the severity of hypoxia.