In addition to the results of our clinical trial of epalrestat in diabetic retinopathy (the open study), the current progress in the clinical trials of aldose reductase inhibitors for the 'triopathy' of complications (neuropathy, retinopathy and nephropathy) in Japan is reported. No data from the placebo-controlled double-blind studies in Japan are shown because a detailed analysis of the effects of epalrestat on diabetic neuropathy and retinopathy is now under way. However, it must be stressed that in the phase III placebo-controlled double-blind studies in neuropathy and retinopathy, epalrestat was effective.