Knowledge of Diabetic Retinopathy before and 18 Years after the Airlie House Symposium on Treatment of Diabetic Retinopathy

In 1968, The Airlie House Symposium evaluated the current knowledge of the natural history of diabetic retinopathy. The effects of tight metabolic control, pituitary ablation, and photocoagulation were discussed at length. Xenon arc photocoagulation was the mainstay of therapy and was usually applied focally to individual patches of new vessels. Photocoagulation of background retinopathy was rarely done. Panretinal photocoagulation was in its infancy, the ruby laser was newly introduced, there were no data on the use of the argon laser, and automated vitrectomy had not been introduced. Participants in the symposium set the stage for the acquisition of valid clinical data from which important therapeutic conclusions have subsequently been drawn by (1) summarizing the areas of consensus and disagreement, (2) devising a standard classification of diabetic retinopathy, and (3) proposing controlled clinical trials for unanswered questions.