To the Editor.
—In the December 1985 issue of the Archives we published data from the Early Treatment Diabetic Retinopathy Study (ETDRS) that demonstratedthat focal photocoagulation of "clinically significant" diabetic macular edema substantially reduces the risk of visual loss.1 As part of the ongoing monitoring of the 23 clinics in this study, we discovered that one of our clinics was not carefully following the study protocol. As a consequence, their data cannot be considered comparable with data from the other clinics. No data from this clinic will be included in any future ETDRS analyses or publications.We have reproduced all of the figures and tables presented in the December 1985 article after deleting the data from this clinic and find essentially no changes in our published results (Table). For example, the Figure shows the comparison of the percentage of eyes that experienced visual loss of 15 or more letters
Aiello LM, Ferris FL. Photocoagulation for Diabetic Macular Edema. Arch Ophthalmol. 1987;105(9):1163. doi:10.1001/archopht.1987.01060090021004