Chiang JF, Sun MH, Chen KJ, et al. - Researchers performed this retrospective clinical cohort study to assess the connection between obstructive sleep apnea (OSA) and diabetic macular edema (DME) and the impact of OSA on refractory DME in patients with type 2 diabetes (T2DM). This investigation was carried out at Chang Gung Memorial Hospital from March 1, 2009, to March 1, 2020. Of the 14,152 patients who had undergone polysomnography (PSG) and whose data were registered on the sleep center's PSG database, 121 patients (242 eyes) with T2DM were registered according to the International Classification of Diseases, Ninth Revision (ICD-9) code for diabetic retinopathy (DR; 3620). A total of 102 eyes (54 patients) were categorized into groups with (n = 40 eyes) or without (n = 62 eyes) DME. Findings suggested that severe OSA is a risk factor for DME and is correlated with refractory DME.