In Sleep Apnea, Intermittent Hypoxia Might Affect Retinal Microvascular Alterations

Researchers found a significant reduction in macular perfusion density in the deep capillary plexus, with no significant difference in the superficial capillary plexus, in individuals with OSA. These reductions in perfusion density at this location were consistently observed across the macular subregions analyzed. Photo: Mayo Clinic. Click image to enlarge. The health impact of obstructive sleep apnea (OSA) extends beyond its well-known cardiovascular and metabolic risks. In eye care, OSA is linked to several ocular vascular diseases, including nonarteritic anterior ischemic optic neuropathy, glaucoma and diabetic retinopathy. Repeated apneic events can cause temporary hypoxemia and elevate vascular resistance, which leads to hypoperfusion of the optic nerve head and reduced retinal blood flow. Recently, researchers in France compared retinal microvascular parameters within the macula and the peripapillary nerve fiber layer regions using OCT-A in participants with OSA vs. controls without the condition to prospectively assess changes in retinal microvascular parameters following OSA diagnosis and management.The team determined that OSA was associated with retinal microvascular alterations in the deep capillary plexus (DCP); however, no consistent longitudinal changes in retinal microvascular parameters were observed after CPAP initiation when accounting for treatment compliance.“Modest short-term changes in macular OCT-A parameters were observed after treatment initiation; however, these changes were not consistent over time and were no longer statistically significant when accounting for CPAP compliance,” the study authors wrote in their paper, which was published in Ophthalmology. “These findings suggest transient microvascular responses following CPAP initiation rather than sustained structural remodeling of the retinal microvasculature.”A total of 162 (324 eyes) participants, including 82 (164 eyes) participants with polysomnography-confirmed OSA and 80 (160 eyes) healthy controls, were analyzed. Among the OSA cohort, 63 received CPAP therapy and were re-evaluated at three to six months and 18 to 24 months. The overall mean age was 54.3 years. There were more men in the OSA group than in the control group (46.3% vs. 28.7%, respectively). Participants with OSA had more cardiovascular comorbidities than their control counterparts, including hypertension, diabetes and vascular disease history. This cohort also had a higher proportion of smokers and higher intraocular pressure. At baseline, axial length and best-corrected visual acuity were comparable between the two groups.At baseline, OSA participants exhibited a significant reduction in retinal vessel density (VD) and perfusion density in the DCP. No significant differences were observed in the superficial capillary plexus, foveal avascular zone or peripapillary regions. Retinal VD and perfusion density remained overall similar after CPAP initiation throughout the follow-up when adjusted for treatment compliance.“We did not observe significant differences in OCT-A microvascular parameters between participants with mild–moderate OSA and those with severe OSA,” the researchers wrote. “One possible explanation is a threshold effect, whereby microvascular alterations occur early in the disease course and plateau beyond moderate severity, limiting the detectability of additional changes at more severe stages.”The team suggested that the apnea-hypopnea index may be insufficient to capture the true hypoxic burden, such that disease severity defined by the index does not necessarily translate into a linear gradient of retinal microvascular damage. Taken together, their results suggest that intermittent hypoxia may induce early vascular adaptations that do not scale proportionally with OSA severity.“Overall, these results highlight the potential relevance of retinal OCT-A metrics as exploratory biomarkers of OSA-related microvascular alterations, while underscoring the need for cautious interpretation of longitudinal CPAP-related effects,” they concluded. Click here for the journal source. Germanese C, Georges M, Bonniaud P, et al. Characterization of retinal microvascular changes in obstructive sleep apnea using optical coherence tomography angiography: data from the ORNET Study. Ophthalmology. February 1, 2026. [Epub ahead of print]. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.