AKR1B1 and retinal disorder: Epalrestat is a carboxylic acid derivative that inhibits aldose reductase, a rate-limiting enzyme of the polyol pathways.[1–3] In hyperglycemia, epalrestat, an uncompetitive aldose reductase inhibitor, significantly reduces intracellular sorbitol accumulation, which has been related in the pathogenesis of late-onset diabetic complication like neuropathy, retinopathy and nephropathy.[2–3]