Leber's hereditary optic neuropathy
Leber's optic atrophy ( Synonym: hereditary optic neuropathy liver (LHON ), Leber's optic neuropathy, Leber's hereditary optic atrophy or liver atrophy ) is a rare hereditary disease of the ganglion cells of the optic nerve and belongs to the group of mitochondrial disorders. An initially often unilateral onset followed within a maximum period of nine months as a rule, the disease of the other eye.
As the disease progresses it comes to loss ( degeneration) of fibers of the optic nerve, especially in its temporal range. This leads to decreased perception of the colors red and green, the central visual field loss with a corresponding loss of visual acuity and eventually blindness. The funduscopy shows a typical finding of the fundus with Pseudopapillenödem and watered-down papilla, arteries extensions and peripapillary telangiectasia. A complete loss of visual acuity can already directly present in disease occurrence or evolve continuously over a period of up to two years. The prospect of a restoration of visual acuity is low. In severe cases, additional neurological and cardiac symptoms may occur.
The frequency ( prevalence) of Leber's optic atrophy is approximately 1:50,000. Other sources speak of 1:100,000 mainly affects men between the ages of 15 and 35. For women and children, the disease is less prevalent. It can be inherited only by women to their children ( maternal ), but not from diseased men or those who are indeed genetic material, but otherwise clinically healthy. The cause of a defect in complex I of the respiratory chain is suspected. The defect is due to point mutations in the positions 3460, 11778 and 14484 of the mitochondrial genome. The diagnosis is made based on the clinical picture and requires a molecular genetic detection of the point mutation. Not infrequently, a retrobulbar neuritis is assumed at the beginning of the disease. There is as yet no established therapy. An effective treatment time is intensively studied for.
Leber's optic atrophy was named after the German ophthalmologist Theodor Carl Gustav of liver, first described the late 19th century the disease.
Clinical picture
Subjective signs exist at the beginning of the disease in a diminution in the color recognition for red and green, followed by loss of central vision. Through the central scotoma patients often try to look with parafoveolaren retina an object, giving the impression that they would see past the object. In about half the cases Leber optic atrophy begins on one side and then attacks over a period of days to months the other eye. The Endsehschärfe, which occurs after a maximum of about two years, is around 2-5 percent. The derivation of a pattern - VEP provides a rule for all pattern sizes no significant responses to stimulation.
The fundus has initially in the acute stage a abgeblasste papilla, which also occur in other diseases of the optic nerve head and can often lead to an initial misdiagnosis and treatment in the absence of molecular genetic investigation. It comes in the further course to hyperaemia, dilation of arterioles tortuous vessels and peripapillary telangiectasia. The perimetric studies show a clear central Farbskotom for red and green, followed by a relative and later absolute central scotoma for white. Due to the primary degeneration of the retina and the optic nerve may lead to secondary changes in the optic tract and lateral geniculate body.
Therapy
As a negative impact of cyanide -containing substances is suspected on the disease process, the absence of tobacco, alcohol and other blue acidic foods (nuts, bitter almonds, cabbage, etc.) is displayed. An effective treatment is yet not known, but an extensive study at the Universities of Munich and Newcastle showed in the use of the active ingredient Idebenone significant progress. The approval of a new drug for the indication of LHON in the European market has meanwhile requested.