The role of trace elements in the pathogenesis of ocular surface diseases in type 2 diabetes mellitus: current concepts and clinical perspectives

Type 2 diabetes mellitus (T2DM) represents a significant risk factor for the development of ocular surface pathology, with the prevalence of dry eye syndrome, meibomian gland dysfunction, and chronic blepharitis exceeding that in the general population by 2–3 times. This review provides a comprehensive analysis of the role of trace element imbalance in the formation and progression of ocular surface diseases in T2DM. Particular attention is paid to the aspects of the influence of deficiency or excess of zinc, copper, selenium, magnesium, and iron on key pathogenetic links: oxidative stress, chronic inflammation, microangiopathy, neuropathy, and impaired reparative processes. Modern data on changes in the trace element profile in the systemic bloodstream, tear fluid, and meibomian gland secretion in patients with T2DM are systematized. The relationships between specific disorders of trace element homeostasis and clinical phenotypes of ocular surface damage are considered. Evidence is presented indicating that trace element imbalance acts not as a passive marker, but as an active participant in the pathological cascade, that determines the nature and severity of ophthalmic manifestations of T2DM. Promising research directions are outlined, including the development of methods for non-invasive assessment of the ocular surface trace element status, the creation of targeted correction tools, and the integration of the trace element approach into personalized algorithms for managing patients with diabetic eye involvement.