The prognosis of diabetic retinopathy in patients with type 2 diabetes since 1996-1998: the Skaraborg Diabetes Register.

Diabetes mellitus is the main reason for visual impairment among patients of working ages. The aim of this paper was to investigate the prognosis of eye complications in patients with diabetes during 10 years of follow-up and contributing risk factors. Data from ophthalmological records (occurrence of retinopathy and laser treatment and visual acuity), and clinical data (blood pressure, glycosylated hemoglobin (HbA1c), body mass index (BMI), and antihypertensive treatment) from the Skaraborg Diabetes Register were retrieved in the Skaraborg Screening Program of 1,258 patients diagnosed during 1996-1998. Kaplan Meyer survival analysis and Log Rank test were used to analyze eye complications in 773 patients with type 2 diabetes and ≤70 years at diagnosis. Visual acuity was above the limit for driving license in 96 % of 548 patients and only nineteen patients were treated by laser. At diagnosis of diabetes, mean HbA1c was 6.7 ± 1.7 % (59 ± 7.1 mmol/mol), and systolic blood pressure was 142.9 ± 0.7 mmHg; neither changed significantly during follow-up. Retinopathy appeared about 1 year, and maculopathy 2 years earlier, if HbA1c ≥ 7 % (63 mmol/mol) at diagnosis (p < 0.001 and p < 0.006). Antihypertensive treatment, higher BMI, and higher age at diagnosis were associated with less retinopathy during follow-up. Most patients with diabetes develop little retinopathy for the first 10 years after diagnosis. High HbA1c at baseline was associated with retinopathy and maculopathy during follow-up. Antihypertensive treatment, probably a proxy for regular controls and early detection of diabetes, was associated with less retinopathy.