Effect of duration of diabetes mellitus on the prevalence of diabetic retinopathy in patients with type 2 diabetes and metabolic syndrome

Aim. To study effect of duration of diabetes mellitus on the prevalence of diabetic retinopathy (DR) in patients with type 2 diabetes (DM2) and metabolic syndrome (MS) or without it. Materials and methods. The study included 115 patients with type 2 diabetes and metabolic syndrome and 45 patients with DM2 without MS (controls). Of 115 MS patients and of 45 control ones, 42 and 17 respectively presented with different forms of DR. Ophthalmological examination was performed by generally accepted methods including visiometry, tonometry, biomicroscopy, ophthalmoscopy, and fluorescent angiography. Results. The study revealed a well-apparent tendency toward an increase of DR occurrence in MS patients with duration of DM2 (10.0%, 53.1%, 82.6% during 0-4, 5-9, and 10 or more years respectively). Significant difference between DR incidence was recorded in MS patients having DM2 for 0-4 and 5-9 years (p< 0.001, FET). Similar difference was documented in MS patients with the duration of DM2 5-9 and 10 or more years (p< 0.01, FET). Analogous tendency was observed in control group (20.8%, 53.8% and 62.5%). The difference between DR incidence in control patients with DM2 0-4 and 5-9 years in duration was statistically significant (p< 0.01, FET) unlike the difference between DR incidence in DM2 of 59 and over 10 years (p > 0.05, FET). Correlation between occurrence of DR and HbA(1c) levels failed to reach statistical significance (r bs = 0.023, p> 0.05 in MS patients and r bs = 0.064, p> 0.05 in controls). Conclusion. Occurrence of DR increases with duration of DM2 with and without MS but fails to correlate with HbA(1c) levels in either condition.