More recently, the detection of AR in the pericytes of retinal capillaries -- cells that are involved very early in the evolution of diabetic retinopathy -- suggests that this enzyme may also play a role in the pathogenesis of this disorder. Scientists now know that AR is present in nerve tissue, and they speculate that in diabetes it induces the depletion of myo -inositol, which leads to the lessening of nerve conduction velocity in diabetic neuropathy.