Severity of background retinopathy in type 1 diabetes increases with the level of long-term glycated haemoglobin.

The relationship between severity of background retinopathy, and prior long-term glycaemic control was studied. Ninety patients with background retinopathy and Type 1 diabetes mellitus, diabetes duration < or = 25 years, and HbA1c monitored > 5 years (on average 9.2 years with 32 HbA1c measurements) were included. All patients had microaenurysms/haemorrhages, 33 had hard exudates, 27 soft exudates, 8 IRMA (intraretinal microangiopathy), three venous beading, and no patient had macula oedema. Patients with mean HbA1c > 8% had higher relative risks for all kinds of background retinopathy, compared to patients with HbA1c < or = 7%. In multiple regression analysis, long-term glycated haemoglobin had significant impact on all types of background retinopathy. Women had lower scores for all types of background retinopathy. No sex differences in HbA1c, age, or duration were found. We conclude that poor long-term glycaemic control is a major risk factor for all types of background retinopathy.