Mediterranean Diet Adherence, Dietary Components, and Vision-Related Quality of Life in Type 2 Diabetes: A Cross-Sectional Study According to Diabetic Retinopathy Status

Background/Objectives: Diabetic retinopathy (DR) is a major microvascular complication of type 2 diabetes (T2D) and a leading cause of visual impairment. The relationships among Mediterranean diet adherence, dietary components, DR, and vision-related quality of life remain incompletely defined. This cross-sectional study evaluated Mediterranean Diet Score (MDS) as the primary dietary endpoint, individual MDS components as secondary endpoints, and micronutrient intakes as exploratory endpoints. Methods: In this single-centre study, 129 subjects with long-standing T2D were classified as no DR (NDR; n = 85), non-proliferative DR (NPDR; n = 36), or proliferative DR (PDR; n = 8). Dietary intake was assessed using a food frequency questionnaire and vision-related quality of life using the NEI-VFQ-25. Results: Subjects with DR had longer diabetes duration than those without DR (18 vs. 16 years, p < 0.01). Overall MDS did not differ by DR status, indicating a null finding for the primary dietary endpoint. In secondary analyses, lower legume consumption was observed among participants with DR and was associated with higher odds of DR in multivariable models. Participants with PDR showed poorer vision-related quality of life, although this finding was limited by the small PDR subgroup and high NEI-VFQ-25 scores in other groups. Exploratory analyses suggested associations between selected micronutrient intakes and NEI-VFQ-25 domains. Conclusions: Overall Mediterranean diet adherence was not associated with DR status. Secondary and exploratory findings should be considered hypothesis-generating and require confirmation in prospective studies.