Hereditary optic neuropathies

Hereditary neuropathies of the optic nerve are genetic defects that cause loss of vision, sometimes in combination with cardiac or neurological abnormalities. Effective treatment does not exist.

Hereditary neuropathies of the optic nerve are usually detected in childhood or adolescence with bilateral symmetrical central loss of vision. The decrease in vision is usually permanent and in some cases progressing. By the time of detection of optic nerve atrophy, its damage has already occurred.

The dominant atrophy of the optic nerve is inherited by an autosomal dominant pathway. This is the most common of the hereditary optic nerve neuropathy with a prevalence rate of 1:10 000-50 000. It is considered visual abiotrophy, premature degeneration of the optic nerve leading to progressive loss of vision. The onset of the disease is in the first decade of life.

With hereditary optic neurology, Leber has an anomaly of mitochondrial DNA, the function of cellular respiration is affected. Although the violation of mitochondrial DNA occurs throughout the body, the primary manifestation is loss of vision. 80-90% of cases of disease in males. The disease has a maternal type of inheritance, all descendants of the woman carrying this sign will inherit it, but only women can transmit it, since the mitochondria are in the cytoplasm of the cell, and the cytoplasm of the descendant (zygote) is determined by the cytoplasm of the egg.

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Symptoms of hereditary neuropathies of the optic nerve

Most patients with a dominant atrophy of the optic nerve do not have concomitant neurological anomalies, although nystagmus and hearing loss are reported. The only symptom is a slowly progressing bilateral loss of vision, usually minor to adulthood. The entire disc of the optic nerve or at times only the temporal part is pale without visible vessels. Characterized by a violation of the perception of yellow-blue flowers. To confirm the diagnosis, molecular genetic testing is performed.

The loss of vision in hereditary optic neuropathy Leber usually begins between 15 and 35 years (within the limits of 1 to 80 years). A painless loss of central vision in one eye is usually replaced by loss of vision in the other eye in weeks or months. It is reported of a simultaneous loss of vision. Most patients have vision less than 20/200 (0.1). Ophthalmoscopic examination can reveal telangiectatic microangiopathy, edema of the layer of nerve fibers around the optic nerve disk and absence of bleeding of the dye during fluorescent angiography. In the end, atrophy of the optic nerve develops.

A subgroup of patients with hereditary optic neuropathy of Leber has a violation of cardiac conduction, an ECG is needed. Other patients may have minimal neurological disorders, such as postural tremor, lack of achilles reflexes, dystonia, spasticity, or multiple sclerosis.

Treatment of hereditary neuropathies of the optic nerve

There is no effective treatment of hereditary optico-neopathies. For hereditary optic neurology, Leber's appointment of glucocorticoids, vitamin supplements and antioxidants is ineffective. In a small study, the use of quinine analogues in the early phase was found. Theoretically justified are the recommendations to avoid substances like alcohol that can deplete the mitochondrial function, but their effectiveness is not proven. Patients should avoid smoking and excessive intake of alcohol. For cardiac and neurological anomalies, patients should be referred to specialists. Help devices with low vision can be useful. Genetic consultation is recommended.