Retinal vascular tortuosity in obstructive sleep apnea

PURPOSE Endothelial dysfunction and vascular disease are common in obstructive sleep apnea (OSA). We sought to examine the retinal vascular manifestations of OSA. METHODS Nine consecutive patients with OSA underwent ophthalmic examination regardless of any ocular complaints. Seven patients without OSA matched for demographics were used as controls. Fundus photographs from both eyes were used to quantitate retinal vascular tortuosity of the temporal arterial and venous arcades using ImageJ digital analysis software. The tortuosity of each vessel from the optic disc rim to the crossing point of a 5 disc diameter (5DD) circle and 10 disc diameter (10DD) circle centered on the optic disc were quantitated. RESULTS The mean age of patients with OSA in the study was 52 years ± SD of 10 years and 67 years ± SD of 10 years in the control group. The apnea-hypopnea index in patients with OSA ranged from 12 to 102 events/hr of sleep. The nadir saturation during sleep in patients with OSA ranged from 60% to 87%. There was no significant difference in the frequency of diabetes or hypertension between the groups. Total tortuosity was increased at the 5DD (P = 0.011) and 10DD (P = 0.004) marks. Arterial tortuosity was significantly increased at the 10DD mark (P = 0.016). Venular tortuosity was increased at both the 5DD (P = 0.001) and 10DD (P = 0.028) marks. CONCLUSION Patients with OSA have increased retinal vascular tortuosity as compared to matched controls. Increased tortuosity of the retinal vasculature may be a novel association with OSA. A larger prospective study will be necessary to further explore this relationship and its clinical significance.