ETDRS vision chart study is done in patients with diabetic retinopathy. ETDRS stands for –

Early treatment diabetic retinopathy study (ETDRS) was a multicenter, randomized clinical trial involving 3711 participants designed to evaluate the effectiveness of both organ laser photocoagulation and aspirin therapy in the management of patients with non-proliferative diabetic retinopathy and early proliferative diabetic retinopathy. In addition, it was designed to determine the best time to initiate photocoagulation treatment in diabetic retinopathy.