Diabetic Retinopathy and Cognitive Dysfunction in Type 2 Diabetes Mellitus: A Systematic Review and Meta‐Analysis of Epidemiological Associations and Clinical Implications

AIMS: Type 2 diabetes mellitus (T2DM) is linked to both diabetic retinopathy (DR) and cognitive impairment, yet the consistency and modifiers of this relationship remain unclear. This systematic review and meta-analysis are aimed at quantifying the association between DR and cognitive dysfunction in T2DM and explore variations by cognitive subtype, diabetes duration, follow-up time, and assessment methods. MATERIALS AND METHODS: We searched PubMed, Embase, Web of Science, and Chinese databases from 2000 to March 2025. Observational studies comparing cognitive outcomes in T2DM patients with and without DR were included. Data were pooled using random-effects models. RESULTS: = 85.2%). The strongest associations were observed for mild cognitive impairment (cross-sectional OR = 2.15) and dementia (cross-sectional OR = 2.20; cohort OR = 1.17). Longer diabetes duration (≥ 10 years) strengthened the association in cross-sectional studies (OR = 2.05), but not in cohort studies. Extended follow-up (≥ 10 years) significantly increased the effect in cohort studies (OR = 1.91). CONCLUSION: DR is significantly associated with cognitive impairment in T2DM, particularly dementia and its subtypes. The association is influenced by study design, diabetes duration, follow-up time, and assessment method. DR may serve as a research-level risk signal for cerebral microvascular damage, warranting further prospective studies to validate its clinical utility.