In the print version of the above-mentioned article, the following paragraph on page 413 was corrected and two additional references (51 and 52) were added:

After duration of diabetes, hyperglycemia has been the most consistently associated risk factor for retinopathy. A large and consistent set of observational studies and clinical trials document the association of poor glucose control and retinopathy. The Diabetes Control and Complications Trial (DCCT), a randomized controlled clinical trial of intensive glycemic control versus conventional glycemic control in people with type 1 diabetes, demonstrated that intensive therapy reduced the development or progression of diabetic retinopathy by 34–76% (51). In addition, the DCCT demonstrated a definitive relationship between hyperglycemia and diabetic microvascular complications, including retinopathy (18). Early treatment with intensive therapy was most effective. In addition, intensive therapy had a substantial beneficial effect over the entire range of retinopathy. A 10% reduction in HbA1c, for example from 10 to 9% or from 8 to 7.2%, reduces the risk of retinopathy progression by 43% (52).

The two new references were also added to the References section on page 418:

51. Diabetes Control and Complications Trial Research Group. Progression of retinopathy with intensive versus conventional treatment in the Diabetes Control and Complications Trial. Ophthalmology 1995;102:647–661

52. The Diabetes Control and Complications Trial Research Group. The relationship of glycemic exposure (HbA1c) to the risk of development and progression of retinopathy in the Diabetes Control and Complications Trial. Diabetes 1995;44:968–983

The online version of the article has been corrected to reflect these changes.

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