To compare the progression of diabetic retinopathy in type 2 diabetic patients with mild-to-moderate diabetic retinopathy treated with insulin glargine vs NPH human insulin.

Randomized, open-label assignment of type 2 patients who are on a stable antidiabetic regimen to treatment with either insulin glargine or BID NPH human insulin, with baseline diabetic retinopathy of severity 53/<53 on the ETDRS scale, for 5 years of followup. Outcomes measured by seven-field fundus photography at baseline, 1.5, 3,6,and 9 months, and annually.

Inclusion Criteria:

• type 2 diabetes mellitus for at least 1 year
• treated with oral antidiabetic agents or insulin at stable doses for at least 3 months
• HbA1c between 6 and 12% inclusive
• baseline retinopathy severity not to exceed 53/<53 on the ETDRS scale
• unlikely to require laser surgery or vitrectomy within upcoming year

Exclusion Criteria:

• prior treatment with insulin glargine
• treatment with insulin analogs (eg insulin lispro or aspart) in the year prior to enrollment