Diabetic Retinopathy - Prevention

Some statistics of interest— over a 10 year interval 20% of type I diabetics and 14% of type II develop clinically significant macular edema (DME).  In light of this two major studies were performed in the 1990’s to evaluate the benefit of tight glycemic control for diabetics relative to the severity of DR.

For type I diabetics, the Diabetic Complication and Control Study (DCCT) established two cohorts of diabetics, one with no DR at the time of enrollment (primary prevention group) and the second with mild DR (secondary intervention). Both groups benefited from tight controls as defined by an HgbA1C of 7.0% or less: a 76% risk reduction in the primary prevention cohort and a 50% risk reduction in the secondary intervention group. Of interest, , a short term worsening of DR was seen  in the first two years of the study among the intensive control group in the secondary intervention cohort.  

The United Kingdom Prospective Diabetes Study (UKPDS) studied type 2 diabetics. The intensive treatment group achieved an HgbA1C of 7.0% versus the conventional treatment group, resulting in a 30% risk reduction.  The role of hypertension was also studied. In the intensive treatment group (mean BP of 144/82) a 35% risk reduction was achieved versus conventional control (154/87).

Results from both the DCCT and the UKPDS— study suggests the following treatment goals:

1. HbgA1C of 7.0% or less
2. Fasting plasma glucose of 110 mg/dL or less
3. Systolic BP less than 130, diastolic less than 85
4. LDL less than 110 (from ETDRS, Early Treatment Diabetic Retinopathy Study and other sources)

·         The best treatment is to prevent the development of retinopathy as much as possible. Strict control of your blood sugar will significantly reduce long-term risk of vision loss from diabetic retinopathy. If high blood pressure and kidney problems are present, they need to be treated.

·         There is a blood test called HbA1C which is a great way to monitor your control.  In a non-diabetic, normally about 4% of all hemoglobin cells in the body have glucose attached to them.  This number goes up in diabetics.  A well controlled diabetic typically has a HBA1C level of under 7%. Check with your primary care provider and understand what you own level should be. 

·         Along the same lines, fasting blood sugar is a good marker of diabetic control.  A fasting blood sugar of 110 of less is generally considered very good control.