METHODS	The Action in Diabetes and Vascular Disease : Preterax and Diamicron MR Controlled Evaluation ( ADVANCE ) Retinal Measurements study , a substudy of ADVANCE , is a randomised ( using a central , computer-based procedure ) controlled 2 x 2 factorial trial comprising a double-blind comparison of blood pressure lowering with perindopril-indapamide vs placebo , and an open comparison of standard vs intensive glucose control targeting a HbA ( 1c ) of < or = 6.5 % in 1,602 diabetic patients from ADVANCE centres with access to retinal cameras conducted from 2001 to 2008 .\