To the Editor.
—We reanalyzed the Diabetic Retinopathy Study (DRS) data to address the questions posed by Dr Schiodte1 in the October issue of the Archives concerning the possible effects on intraocular pressure (IOP) of the treatment type (argon laser vs xenon arc photocoagulator) and the use or nonuse of retrobulbar anesthesia. Difference scores for IOP were computed from data for each pair of treated and untreated eyes. Using multiple independent t tests, group means were then compared at each of the ten visits at which IOP was recorded during the first five years of follow-up after randomization. There was no statistical significance (P >.01) or clinical significance (all mean differences were <0.5 mm Hg) found in any of the comparisons examined between either of the treatment groups or the retrobulbar anesthesia groups.Our analysis of the data collected in the DRS revealed no evidence supporting the notion that
Kaufman SC, Ferris FL, Swartz M, Chantry K. Intraocular Pressure in the Diabetic Retinopathy Study. Arch Ophthalmol. 1989;107(3):318. doi:10.1001/archopht.1989.01070010328010