To investigate whether sleep-disordered breathing is a risk factor for iris and/or angle neovascularization in patients with proliferative diabetic retinopathy (PDR).

Cross-sectional comparative case series.

One hundred fifty-one consecutive patients with PDR who underwent surgery in our hospital were divided based on the presence of iris and/or angle neovascularization (NV group, 37 patients) or absence of NV (non-NV group, 114 patients). Pulse oximetry was conducted during the night and the mean SpO₂, 4% oxygen desaturation index (4% ODI times/hour), the lowest SpO₂% during sleep (lowest SpO₂), and the cumulative percentage of time at SpO₂ <90% in analysis times (CT90%) were calculated. When the 4% ODI exceeded 5 times/hour, sleep-disordered breathing was diagnosed. The results were compared between the 2 groups. Preoperative systemic parameters also were analyzed by logistic regression to clarify risk factors for the NV group.

A mean total of 50% (62% of the NV group and 46% of the non-NV group) was diagnosed with sleep-disordered breathing. The mean SpO₂ and lowest SpO₂ did not differ significantly between the 2 groups; the 4% ODI (12.3 vs 6.6) and CT90% (3.8 vs 1.7) were significantly higher in the NV group (P =.02, for both comparisons). Logistic regression analysis identified insulin therapy (odds ratio [OR], 3.01; 95% confidence interval [CI], 1.267.20; P = .01); and 4% ODI (OR, 1.09; CI, 1.011.16; P = .02) as risk factors for the NV group.

In patients with PDR, nocturnal intermittent hypoxia/reoxygenation resulting from sleep-disordered breathing may be a risk factor for iris and/or angle neovascularization.