Sleep-disordered breathing may be risk factor for neovascularization

Am J Ophthalmol. 2011;151(4):604-609.

Patients with proliferative diabetic retinopathy who suffer from nocturnal intermittent hypoxia and reoxygenation could be at risk for iris and angle neovascularization, a study found.

The cross-sectional comparative case series included 151 Japanese patients with proliferative diabetic retinopathy and type 2 diabetes. Researchers conducted nocturnal pulse oximetry and diagnosed sleep-disordered breathing when the 4% oxygen desaturation index (ODI) exceeded five times an hour.

Sleep-disordered breathing was identified in 62% of the 37 patients with neovascularization and in 46% of the 114 patients without neovascularization for a mean total of 50%.

The two groups did not show a significant difference between mean percutaneous oxygen saturation (SpO2) and lowest SpO2, the study said. However, the 4% ODI in the neovascularization group was significantly higher (12.3) than in the non-neovascularization group (6.6, P = .02). The CT90% was also higher in the neovascularization group (3.8) than in the non-neovascularization group (1.7, P = .02).

Insulin therapy (P = .01) and 4% ODI (P = .02) were identified by logistic regression analysis to be risk factors for neovascularization, the study said.

The authors noted a prospective study is necessary to determine whether nasal continuous positive airway pressure could prevent iris and angle neovascularization in patients with proliferative diabetic retinopathy.