Significant retinopathy in young-onset type 2 vs. type 1 diabetes: a clinical observation

Little is known about the burden of severe retinal disease between young-onset type 2 (T2D) and type 1 diabetes (T1D). This study assessed the prevalence of significant retinopathy in young-onset T2D vs. T1D and its predictive factors.

This was a cross-sectional study. Subjects with T1D and T2D diagnosed below age 40 were identified from diabetes eye screening register. Preproliferative, proliferative, maculopathy changes and/or previous laser photocoagulation treatment were considered to have significant retinopathy (SigDR).

A total of 1306 subjects were identified, of whom 842 and 464 had T1D and T2D, respectively. The mean age of diagnosis was significantly lower in T1D subjects (T1D vs. T2D; 20.1 ± 10.3 vs. 32.1 ± 6.0 years, p < 0.0005). Although the T2D cohort had shorter diabetes duration (T1D vs. T2D; 20.8 ± 13.0 vs. 13.7 ± 9.0 years, p < 0.0005), the overall prevalence of SigDR was similar to T1D (T1D vs. T2D; 21.6 vs. 20.9%, p = NS). After adjusting for diabetes duration, the T2D cohort experienced significantly higher prevalence of this complication than T1D after 10 years duration. The age threshold beyond which the T2D cohort began to experience greater burden of SigDR was approximately 50 years. The prevalence of any retinopathy after 15 years duration was 75-80% for both young-onset cohort. Risk factors for SigDR (older age, diabetes duration, systolic BP, HbA1c and creatinine) were similar in both young-onset diabetes cohort with poor glycaemic control being the strongest variable. Lower age of T2D diagnosis was not a predictive factor.

Irrespective of diabetes type, subjects with young-onset diabetes possessed high lifetime risk for retinopathy. However, young-onset T2D cohort was more susceptible to severe retinal disease with substantial burden of this complication by the fifth decade of life.