Optical disease in multiple sclerosis. Results of a transversal study in 57 patients living in Martinique

Introduction: The optical disease observed concurrent with multiple scleros is Is poorly known in blacks because of the rare occurrence of this patholo gy in the black population, The few studies currently available suggest mor e severe problems in black subjects than in Caucasians. Martinique has subj ects who are genetically close or even identical but who acquired multiple sclerosis in two very different endemic areas: some in Martinique and other s in France. Patients and methods: We performed an ophthalmological transversal descript ive study in a population of 57 black multiple sclerosis patients living in Martinique, selected according to the Poser criteria. Patients were divide d into two groups: an M group (26 cases) made up of patients who had never left Martinique or the West Indies and an FM group (31 patients) made up of patients who had lived at least one year in France between the ages of 5 a nd 15. Results: At least one episode of retrobulbar optic neuritis was observed in 16 cases (61.5%) in the M group and in 11 cases (31.5%) in the FM group. T he number of eyes with either one episode or more of retrobulbar optic neur itis or papillitis was higher in the M group, 26 cases (50%) than in the FM group, 14 cases (22.6%). Multiple sclerosis began by a disease of the opti c nerve in 12 cases (46%) in the M group and in 7 cases (22.6%) in the FM g roup. The mean visual acuity is 20/30 in the M group and 20/20 in the FM gr oup. The mean value of the p 100 wave was 131 ms in the M group and 113ms i n the FM group. Discussion: Multiple sclerosis observed in the black population living in M artinique (M group) is characterized by frequent and severe visual problems . The visual phenotype of the FM group is quite similar to the visual pheno type of Caucasians. More than ethnic and genetic factors, the tropical area of acquisition should have an influence on the visual phenotype. For unkno wn reasons, the optical problems appear severe when multiple sclerosis is a cquired in a low endemic area.