Infraorbital Paresthesia as a Potential Indication for Reconstruction of Pure Blowout Orbital Fractures: A Case Report.

Diabetic retinopathy (DR) is one of the most common microvascular complications of diabetes mellitus and remains a leading cause of visual impairment and blindness among working-age adults worldwide (, ). The global burden of DR continues to increase alongside the growing prevalence of diabetes, with more than 100 million individuals estimated to be affected in 2020 and substantially higher numbers projected in the coming decades (–). Chronic hyperglycemia-induced microvascular injury, retinal ischemia, inflammation, and neurovascular dysfunction contribute to the development and progression of DR, which can ultimately result in diabetic macular edema, proliferative retinopathy, and irreversible vision loss (, ). Although established risk factors such as diabetes duration, poor glycemic control, hypertension, dyslipidemia, obesity, and nephropathy are strongly associated with DR, these factors do not fully account for the variability in disease occurrence and progression, highlighting the need to identify additional potentially modifiable risk factors (). Obstructive sleep apnea syndrome (OSAS) is a common sleep-related breathing disorder characterized by recurrent episodes of upper airway obstruction during sleep, resulting in intermittent hypoxia, sleep fragmentation, sympathetic activation, and substantial cardiometabolic stress (, ). OSAS is particularly prevalent among patients with type 2 diabetes mellitus (T2D), with reported prevalence rates ranging from 58% to 86% (). Several biological mechanisms support a potential link between OSAS and DR (, ). Recurrent intermittent hypoxia may promote oxidative stress, systemic inflammation, endothelial dysfunction, vascular dysregulation, and increased expression of hypoxia-inducible factors and vascular endothelial growth factor, all of which have been implicated in the pathogenesis of diabetic retinal disease (, ). Furthermore, OSAS may worsen insulin resistance, blood pressure control, and metabolic homeostasis (), thereby contributing to retinal microvascular injury and accelerating the development of DR. Over the past decade, numerous observational studies have examined the association between OSAS and DR, but the findings have been inconsistent (, ). Previous meta-analyses generally reported positive associations, with pooled odds ratios (ORs) ranging from 1.34 to 2.01 (–). However, these reviews were based predominantly or exclusively on cross-sectional and case-control studies evaluating prevalent DR rather than incident disease (–). For example, Zhu et al. included six case-control studies and reported a pooled OR of 2.01 for the association between OSAS and DR (), whereas García-Sánchez et al. reported a pooled OR of 1.57 based primarily on case-control evidence (). More recently, Simonson et al. found that OSAS was associated with prevalent DR (OR = 1.34), but noted that nearly all included studies were cross-sectional (). Consequently, the temporal relationship between OSAS and DR could not be established, and the findings remained vulnerable to reverse causation and residual confounding. Patients with established DR often have longer diabetes duration, poorer glycemic control, greater comorbidity burden, and worse overall health status, factors that may themselves influence sleep quality and the likelihood of OSAS diagnosis (, ).