What is represented by ETDRS in a diabetic vision chart?

What is represented by ETDRS in a diabetic vision chart? 

• ELECTIVE TREATMENT FOR DIABETIC RETINOPATHY SCALES 

• EXTENDED RX FOR DIABETES REVIEW STUDY 

• EARLY TREATMENT DIABETIC RETINOPATHY STUDY

• EYE TEST DRUM REVIEW STUDY

ANS (C) 

The Early Treatment Diabetic Retinopathy Study (ETDRS) evaluated the effectiveness of laser treatment for the leaking phase of diabetic retinopathy. Patients with macular edema (leaking near or within the center part of the retina, that part which is used for reading, driving etc, see photo), were randomly assigned to receive either laser treatment to the leaking microaneurysms or were simply observed without treatment. The results showed that timely laser treatment reduced the risk of moderately severe visual loss by about three-fold at three years after treatment and significantly increased the likelihood of moderate visual gain. More importantly, this study provides the treating retinal specialist with a detailed guide as to when laser therapy is necessary based upon the location of leaking areas. With this knowledge, we can treat patients at the appropriate time so as to prevent vision loss and conversely, avoid unnecessary treatment for those for whom it is not beneficial.