[Clinical manifestation and molecular identification of patients with Leber's hereditary optic neuropathy in a national reference center for neuro-ophthalmology in Cuba]. / Manifestaciones clínicas e identificación molecular de pacientes con neuropatía óptica hereditaria de Leber en un centro de referencia nacional para la neuroftalmología en Cuba.

INTRODUCTION: Leber's hereditary optic neuropathy (LHON) is a mitochondrial disorder, confirmed at a molecular level 10 years ago. This had permitted better understanding of the condition. Since 1998, the Instituto de Neurología y Neurocirugía has used these techniques for the study of mutations which are considered to be the origin of the disorder. PATIENTS AND METHODS: We describe the characteristics of 14 cases from 10 families with LHON and the molecular confirmation found between 1994 and 1998 in the Instituto de Neurología Neurocirugía de Cuba. We also review the few cases seen in the previous 18 years. These were from only two families. They were diagnosed on clinical grounds and in view of maternal inheritance. RESULTS AND CONCLUSIONS: In 80% of the families in which the presence of primary mutations was investigated there was A117789, and in 20% A3460G. The average age of appearance was 28 years. The ages of onset were within the limits of 11 years and 48 years. There were 43% women. Two cases were considered to be sporadic. The clinical features corresponded to those described in such cases, with severe visual defects, central scotomas, very reduced colour vision and severely altered visual evoked potentials, with normal diffuse light and pattern electroretinograms. An improvement in visual acuity of 0.2 was seen in two cases. Microangiopathy, described as characteristic of the early stages of this disorder was detected in five cases, in at least one eye. The others had different degrees of optic atrophy. Two generations of one complete family, all with mutation 3460, were studied. In several families with this mutation alterations were found in the colour vision test of Farnsworth Munsell Hue 100 and also microangiospathy of the retina.

[Leber's hereditary optic neuropathy and its possible relation to a recent epidemic in Cuba]. / Neuropatía óptica hereditaria de Leber y su posible relación con la reciente epidemia de Cuba.

INTRODUCTION: This century, the greatest epidemic affecting the nervous system was notified in Cuba seven years ago. At the present time the epidemic continues although to a lesser extent. The clinical findings of the illness were mainly bilateral optic neuropathy sometimes accompanied by other symptoms and peripheral neuropathy. The similarity of the optic form of the illness with Leber's hereditary optic neuropathy, and their common risk factors, were obvious from the beginning. PATIENTS AND METHODS: Statistics from the national reference department of neuro-ophthalmology of the Instituto de Neurologia de Cuba were reviewed. From these it was evident that the number of cases of Leber's hereditary optic neuropathy had increased in recent years, coinciding with the period of epidemic and endemic Cuban neuropathy. Many of these patients had previously been diagnosed as having epidemic optic neuropathy. RESULTS: We describe the characteristics of a group of these patients and discuss the differences and possible relationship between the two conditions. In the case of epidemic optic neuropathy, there is strikingly simultaneous loss of vision, less visual changes with much smaller cecocentral scotomas, loss of ganglion fibres of the retina around the papillomacular bundle, a good response to multivitamin treatment, and increased frequency of association with peripheral sensory neuropathy. CONCLUSION: This analysis reinforces the hypothesis that many patients with Leber's hereditary optic neuropathy, which started at the time of the epidemic, were incorrectly classified as suffering from this, and also perhaps their condition worsened due to the toxic nutritional features common to both conditions.