[Dyschromatopsia: manifestation or epiphenomenon in the course of diabetic neuropathy]

We performed a study in 92 diabetic patients (76 Type 1 and 16 Type 2) without retinopathy to determine the relation between diabetic dyschromatopsia and neuropathy, which has been evoked in previous studies. Color vision was explored with Lanthony's desaturated D 15 panel. Peripheral nervous function was explored with an electrophysiological score which has been beforehand validated. Moreover evoked visual potentials were performed in 38 diabetic subjects in order to determine whether dyschromatopsia was related to an impairment of central optic pathways. Fifty-one among the 92 diabetic subjects had a blue-yellow dyschromatopsia. Among the recorded parameters, only peripheral nervous impairment was significantly more frequent in the group with dyschromatopsia than in the group without. Ten among 38 diabetics had impairment of the evoked visual potentials. Frequency of alteration of evoked visual potentials was not different between the group with and the group without dyschromatopsia. Our results confirm the relationship between dyschromatopsia and the alteration of the nervous function in diabetic subjects. In return, lack of significant modification of evoked visual potentials among diabetic patients with dyschromatopsia and the blue-yellow axis of dyschromatopsia are in opposition with a direct neurological origin of dyschromatopsia. We therefore evoke a common process in the beginning of the diabetic dyschromatopsia and of peripheral neuropathy.