OBJECTIVE: To examine if there was a variable of glycemic exposure having a common linear relation against retinopathy level regardless of duration of diabetes which might contribute to diabetes care through retinopathy prediction, we analyzed data from the Diabetes Control and Complications Trial/ Epidemiology of Diabetes Interventions and Complications. RESEARCH DESIGN AND METHODS: To exclude possible disturbing effect of metabolic memory, we examined only selected subgroup of participants who had glycohemoglobin A1c (A1C) data of total period of type 1 diabetes. Relations between three A1C variables and retinopathy at three different timepoints of duration were compared using simple linear regression analysis. RESULTS: Between only ?excessA1C and retinopathy, the linear regression lines at the three timepoints appeared to be similar in both slope and intercept. CONCLUSIONS: ?excessA1C, the sum of yearly excess A1C during total period of diabetes, may have a potential to predict retinopathy regardless of duration in type1 diabetes.