Obstructive Sleep Apnea in Patients with Branch Retinal Vein Occlusion: A Preliminary Study

PURPOSE Our study aimed to determine whether obstructive sleep apnea (OSA) is common among branch retinal vein occlusion (BRVO) patients without systemic risk factors using a Watch PAT-100 portable monitoring device. METHODS The study participants included consecutive patients with BRVO of less than 3 months duration without any risk factors known to be associated with OSA (diabetes, coronary artery disease, stroke, hematologic diseases, autoimmune disease, etc.) except for hypertension. All patients underwent full-night unattended polysomnography by means of a portable monitor Watch PAT-100 device. The apnea-hypopnea index (AHI) was calculated as the average number of apnea and hypopnea events per hour of sleep, and an AHI score of five or more events was diagnosed as OSA. RESULTS Among 19 patients (6 males and 13 females), 42.1% (8 of 19) had an AHI reflective of OSA. In the 13 patients who had no concurrent illness, including hypertension, 30.8% (4 of 13) had positive test results for OSA; three of these patients were ranked as mild OSA, while one had moderate OSA. The OSA group had an average AHI of 12.3 ± 7.8, and the average AHI was 2.0 ± 0.9 in the non-OSA group. Although it was not statistically proven, we found that OSA patients experienced a more severe form of BRVO. CONCLUSIONS We found a higher than expected rate of OSA in BRVO patients lacking concomitant diseases typically associated with OSA. Our findings suggest that OSA could be an additional risk factor in the pathogenesis of BRVO or at least a frequently associated condition that could function as a triggering factor.