Abstract
A long-term comparative clinical trial with oral hypoglycemic agents was performed to evaluate their efficacy in diabetic retinopathy. In the preceding papers, the objective of the trial, methods used, background factors of the patients and the results of analyses of medical data on the control of diabetes were discussed. This paper deals with the ophthalmologic evaluation of diabetic retinopathy as the main aspect of the trial. Ophthalmoscopy and photofluorography of the eye ground were performed in all cases to compare the results obtained before with those after treatment (at 18 to 24 months). Three new methods for evaluating the disease were introduced: classification according to the severity of the disease, evaluation by paired comparison and ranking of photofluorographic findings (by a panel of three ophthalmologists). All procedures of evaluation were performed by a blind technique. It was found that the results of evaluation varied with the method employed: the rate of aggravation was lower with Gliclazide (SE) when estimated according to the severity of the disease, whereas no difference existed among the groups when the parameter was evaluated by the paired comparison method. The rate of aggravation estimated by ranking of photofluorographic findings, in turn, was higher with SE than with other sulfonylureas (SU). Evaluation of individual parameters also yielded results that varied considerably from method to method, indicating the questionable validity of the combination of the methods of evaluation employed. Reasonably uniform results were obtained, however, with regard to the incidence of progression to proliferative retinopathy, which was higher with SU with a figure of 6.6 per cent compared to 1.8 per cent with SE and 0.8 per cent with Diet; such a tendency was confirmed by the funduscopic findings. It was thus concluded the SE is an oral hypoglycemic agent that is both effective and safe in the treatment of diabetes and worthwhile, particularly in case of diabetic retinopathy.
