Different Phenotypes of Mild Nonproliferative Diabetic Retinopathy with Different Risks for Development of Macular Edema (C-TRACER Study)

Abstract

Purpose: To evaluate diabetic retinopathy (DR) progression in patients with diabetes mellitus type 2 in 2 populations of different ethnicity.

Methods: A prospective observational study was designed to follow eyes/patients with mild nonproliferative DR, for 2 years or until the development of central-involved macular edema (CIME), in 2 centers from different regions of the world. A total of 205 eyes/patients fulfilled the inclusion/exclusion criteria and were included in this study. Ophthalmological examinations, fundus photography with RetmarkerDR analysis, and optical coherence tomography were performed at baseline and at 6, 12 and 24 months.

Results: Of the 158 eyes/patients that completed this study, 24 eyes developed CIME and 134 eyes were present at the last study visit. Eighty-eight eyes (56.4%) were classified as phenotype A, 49 (31.4%) as phenotype B, and 19 (12.2%) as phenotype C. Phenotype A is associated with a very low risk for development of CIME in comparison with phenotypes B and C. The OR for development of CIME was 19.0 for phenotype B and 25.1 for phenotype C.

Conclusion: Eyes in the initial stages of DR show different phenotypes with different risks of progression to ME. The phenotypes associated with increased risks of progression show different distributions in patients of different ethnicities.

Keywords: Biomarkers; Diabetes; Macular edema; Nonproliferative diabetic retinopathy; Phenotypes.