Association of Advanced Glycation End Products with Diabetic Retinopathy Severity in Lithuanian Patients

Background and Objectives: Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus (DM) and a leading cause of blindness among working-age adults. Advanced glycation end products (AGEs) contribute to DR pathogenesis through oxidative stress and inflammation. This study aimed to evaluate the association between AGE levels and DR severity in Lithuanian patients with type 1 (T1D) and type 2 (T2D) diabetes. Materials and Methods: An observational cross-sectional study enrolled 152 patients with T1D and T2D from a tertiary university hospital. AGE values were measured with a non-invasive AGE Reader device. DR severity was assessed through ophthalmological examination. Results: The overall DR prevalence was 54.6%. AGE values increased with the severity of DR, though not significantly between the DR groups (p = 0.386). The mean AGE value was higher in T2D compared with the T1D group (2.429 vs. 2.217, p = 0.011). In T1D, AGE values were higher in the advanced DR group compared with the non-DR patients (2.445 vs. 1.905, p = 0.007), whereas no significant difference was found in the T2D subgroups. In T1D, AGEs correlated positively with both DM duration and higher HbA1c (p < 0.05). Patients with AGE values > 2.35 in T1D and 2.15 in T2D had an increased likelihood of having advanced DR. Patients in the non-DR group had significantly lower AGE values compared to those in the advanced DR group (OR = 0.118, 95% CI 0.025-0.566, p = 0.008). Conclusions: AGEs measured using skin autofluorescence may indicate DR severity in T1D but not in T2D and might not be a suitable standalone risk predictor. DM duration remains a significant determinant of advanced DR, highlighting the importance of early monitoring and timely intervention.