Multicentre trial of xenon-arc photocoagulation in the treatment of diabetic retinopathy. A Randomized controlled study. Interim report.

An interim analysis of the cases in the British Multicentre Photocoagulation Trial shows that treated eyes with maculopathy retain better visual acuity than untreated eyes. The difference of the change in the mean visual acuities of the treated and untreated eyes is small but statistically significant. In those with new vessels as the predominant feature, there is a trend for treated eyes to have better visual acuity than untreated eyes, but the difference in the mean visual acuity of the two groups is not statistically significant.