Sleep duration and nocturnal oxygen desaturation showed distinct associations with retinal arterial characteristics, suggesting that OCT-based vascular metrics may serve as noninvasive indicators of sleep-related microvascular alterations.
Key Findings
Results
Shorter sleep duration was associated with narrower retinal arterial outer and inner diameters.
Study included 5991 adults from the community-based Nagahama Study in Japan (2012–2016), mean age 57.6 years, 30.6% male.
Nocturnal oxygen desaturation was evaluated using the 3% oxygen desaturation index (3%ODI) from synchronized actigraphy and oximetry recordings.
These associations were distinct from those observed with sleep duration, suggesting different pathophysiological mechanisms.
Results
Sleep efficiency showed no significant associations with any retinal vascular parameter.
Sleep efficiency was defined as total sleep time divided by sleep period time (SPT), derived from actigraphy.
No significant associations were found between sleep efficiency and retinal arterial outer diameter, inner diameter, or wall thickness.
This contrasts with the significant findings for sleep duration and nocturnal oxygenation.
Methods
Retinal arterial structure was assessed noninvasively using OCT-derived measurements of peripapillary B-scans in a large community-based sample.
Retinal arterial parameters measured included outer diameter (OD), inner diameter (ID), and wall thickness from peripapillary OCT B-scans.
The study design was cross-sectional, conducted within the Nagahama Study (2012–2016).
All 5991 participants underwent both OCT imaging and wrist actigraphy.
The authors propose that OCT-based vascular metrics may serve as noninvasive indicators of sleep-related microvascular alterations.
Results
Sleep duration and nocturnal oxygen desaturation showed distinct, rather than overlapping, patterns of association with retinal arterial characteristics.
Shorter sleep duration was linked to narrower arterial diameters (both OD and ID), while higher 3%ODI was linked to thicker walls and wider OD.
The divergent patterns suggest that inadequate sleep duration and nocturnal hypoxia may affect the microvasculature through different mechanisms.
Sleep efficiency, unlike sleep duration and 3%ODI, was not significantly associated with any vascular parameter.
What This Means
This research suggests that how long a person sleeps and how well their blood oxygen levels are maintained during the night are each linked to differences in the structure of tiny blood vessels in the eye. Using a non-invasive eye-scanning technology called optical coherence tomography (OCT), researchers measured the size and wall thickness of small retinal arteries in nearly 6,000 Japanese adults. They found that people who slept for shorter periods tended to have narrower retinal blood vessel diameters, while people who experienced more frequent drops in blood oxygen during the night (a pattern common in sleep apnea) tended to have thicker vessel walls and wider outer diameters. These two sleep-related factors appeared to affect blood vessel structure in different ways, suggesting they may harm the microvasculature through distinct biological pathways.
The study is notable because it used objective measurements — wrist actigraphy for sleep and a pulse oximeter for nighttime oxygen levels — rather than relying on self-reported sleep habits, which can be inaccurate. The large community-based sample also strengthens confidence in the findings. Interestingly, sleep efficiency (how much of time in bed was actually spent sleeping) was not meaningfully linked to any vascular measure, highlighting that sleep duration and oxygen levels during sleep may be more important than sleep fragmentation alone for microvascular health.
This research suggests that the retinal blood vessels — which are accessible and visible without invasive procedures — could potentially serve as a 'window' to detect subtle vascular changes related to poor sleep or nighttime breathing problems. If confirmed by future longitudinal studies, these findings could have implications for understanding how sleep disorders contribute to cardiovascular and vascular disease risk over time.
Xiang R, Muraoka Y, Murase K, Kogo T, Sato S, Hidaka Y, et al.. (2026). Associations of sleep duration and nocturnal oxygenation with OCT-derived retinal arterial structure.. Microvascular research. https://doi.org/10.1016/j.mvr.2026.104912