Abstract
Visual impairment is one of the most debilitating complications of diabetes mellitus (DM), primarily due to diabetic retinopathy (DR), diabetic macular edema (DME), cataract, and glaucoma. These conditions contribute significantly to the global burden of vision loss. This narrative review synthesizes current evidence on the prevalence, pathophysiology, risk factors, screening methods, therapeutic strategies, and public health implications of DM-associated visual impairment. A targeted literature search was conducted across PubMed, MEDLINE, Web of Science, and Scopus, focusing on systematic reviews, meta-analyses, and comprehensive narrative articles. Key data on global and regional prevalence, underlying mechanisms, and emerging interventions were analyzed. DR affects nearly one-third of individuals with diabetes, with 6.2% experiencing vision-threatening DR (VTDR) and 4.1% developing clinically significant macular edema (CSME). OCT-based studies show a DME prevalence of approximately 5.5%. Major pathophysiological mechanisms include advanced glycation end product accumulation, polyol pathway activation, oxidative stress, and chronic inflammation. Risk factors include diabetes duration, poor glycemic and blood pressure control, nephropathy, age, and socioeconomic disparities. Advances in screening—especially via teleophthalmology and AI—and treatments such as anti-VEGF therapy, laser photocoagulation, and vitrectomy are central to disease management. Novel therapies like gene and stem cell interventions are under development. Visual impairment in DM is common but largely preventable. Early detection, effective treatment, and addressing systemic and social determinants are essential. Enhanced public health strategies and expanded access to care, especially in low-resource settings, remain urgent priorities.