How Is Diabetic Retinopathy Diagnosed?
Since diabetic retinopathy (DR) typically won’t have symptoms until so late in its progression that any successful treatment is unlikely, the best diagnostic approach is via screening. Early detection of changes that are unnoticed by the patient can allow early treatment to be more beneficial.
Screening can be done by an ophthalmologist or an appropriately trained specialist, and thereafter serial retinal photographs can be used to follow the progress of eye conditions. Ophthalmoscopy with the help of pupil dilation is used in conjunction with retinal photography.
Type 1 DM is diagnosed more quickly than Type 2 DM which has an insidious onset. This allows Type 1 DM to be diagnosed earlier, before any eye damage occurs. Initial screening in Type 1 DM should begin within 3-5 years of diagnosis; it is unusual for retinopathy to begin before that.
With Type 2 DM, due to its insidious onset, eye damage may already have occurred by the time of diagnosis, so screening should begin immediately upon diagnosis. If there is no retinopathy, repeat screens can be done every 2-3 years; if there is, then annual exams should be scheduled.
Pregnancy with pre-existing diabetes accelerates the progression of any retinopathy, so women with diabetes should have comprehensive eye exams before any planned pregnancy or immediately if pregnancy occurs first. After delivery, screens should be done more frequently than in diabetics without a recent pregnancy.
The frequency of screening should be individualized, based on the presence or absence of abnormal findings or retinopathy.