Microaneurysm count as a predictor of long-term progression in diabetic retinopathy in young patients with type 1 diabetes: the Danish Cohort of Pediatric Diabetes 1987 (DCPD1987)

PURPOSE: To investigate microaneurysm (MA) count as a predictor of long-term progression of diabetic retinopathy (DR) in young patients with type 1 diabetes mellitus (T1DM).

METHODS: We examined 185 patients with T1DM at baseline (1995) and at follow-up (2011). At baseline, mean age and duration of diabetes were 20.6 and 12.9 years, respectively. Two-field (1995) and seven-field (2011) fundus photographs were taken in accordance with the European Diabetes Study Group (EURODIAB) and the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, respectively. DR was graded in accordance to the ETDRS protocol, allowing for non-standard photography at baseline. Baseline MAs were counted; patients without DR and those with MAs only were included. Multivariable logistic regressions were performed to investigate MA-count as a predictor of two-step progression, progression to proliferative DR (PDR), and incident diabetic macula edema (DME).

RESULTS: We included 138 patients (138 eyes). Of these, 58 had no retinopathy and 80 had MAs only. At follow-up, rates of two-step progression of DR, progression to PDR and incident DME were 52.9, 21.7, and 10.1 %, respectively. In logistic regression models, MA count was able to predict progression to PDR (OR: 1.51 per MA; 95 % CI: [1.04-2.20]) and DME (OR: 1.69 per MA; 95 % CI: [1.05-2.77]), but not two-step progression (OR 0.91 per MA, 95 % CI: [0.64-1.31]).

CONCLUSIONS: In younger patients with T1DM, MA count predicts long-term incidence of PDR and DME. This demonstrates that early DR is a warning sign of late retinopathy complications and that the number of MAs is an important factor for long-term outcome.