Approaches to the epidemiology of NOHL in the region of Madrid: Survey of neuro-ophthalmologists

Abstract

Objective: To estimate the epidemiology of Leber's optic neuropathy (NOHL) in the Region of Madrid.

Material and methods: The neuro-ophthalmologists who work at public hospitals of the CAM were interviewed by telephone. They were asked about the number of patients with NOHL that they had diagnosed during the time that they had been responsible for the neuro-ophthalmology department of that public hospital. The time worked and the population attended by the hospital were used to calculate the number of inhabitant-years in follow-up by each center during the corresponding period. The basic information of each case (date of birth, mutation, date of visual loss) was registered to avoid duplications.

Results: Our work estimates a global incidence of 2.34 cases for 10,000,000 inhabitants-year and a prevalence estimated from incidence of one case for each 106.682 inhabitants. This prevalence was very similar in all the studied areas and considerably lower than that reported by other studies.

Conclusion: This work constitutes the first approach to the epidemiology of this disease in Spain. The prevalence of LHON in the region of Madrid, is probably lower than that reported in the literature in other regions. The prevalence and the incidence were homogeneously low in the 26 studied areas.

Keywords: Atrofia óptica; Discapacidad visual; Enfermedad mitocondrial; Enfermedad rara; Mitochondrial disease; Nervio óptico; Optic atrophy; Optic nerve; Rare disease; Visual disability.