Retrospective evaluation of macula by optical coherence tomography in diabetic patients with obstructive sleep apnea

Diabetic retinopathy is the most common microvascular complication of diabetes mellitus. It is one of the main causes of visual impairment in developing countries. The increase in VEGF, which plays an important role in the pathogenesis of diabetic retinopathy, is suggested to be triggered by hypoxia, and the retina is known to consume more oxygen in the dark, that is, at night. This mechanism can lead to ocular effects, in particular worsening of diabetic maculopathy, by causing an increase in VEGF due to recurrent nocturnal desaturation episodes of obstructive sleep apnea syndrome. The present study aims to evaluate patients diagnosed with diabetes mellitus and grouped according to apnea-hypopnea index through polysomnography performed for the diagnosis of obstructive sleep apnea syndrome. The foregoing evaluation is based on the changes in retinal structures, especially in macula through optical coherence tomography. The present study also aims to examine the effects of diabetes exposure time on macular and retinal structures via optical coherence tomography. Central macular edema was seen more in the severe OSAS group than in the mild-moderate OSAS group. In addition, RNFL in inferior, temporal, and nasal quadrants were found to be statistically significantly thinner in the severe OSAS groups. The results obtained revealed that the increase in the severity of OSAS may cause retinal pathologies in diabetic patients. OSAS and DM are two different clinical conditions with serious social and individual effects. An accurate understanding of the effects of these two separate clinical entities on the eye, especially on the retina, is of great importance to prevent and treat the disorders. Overall, this study aimed to serve as a base for future studies.