eye disorders
Hereditary Optic Neuropathies
Symptoms and Signs of Hereditary Optic Neuropathies
Most patients with dominant optic atrophy have no associated neurologic abnormalities, although nystagmus and hearing loss have been reported. The only symptom is slowly progressive bilateral vision loss, usually mild until late in life. The entire optic disk or, at times, only the temporal portion is pale without visible vessels. A blue-yellow color vision deficit is characteristic. Vision loss in patients with Leber hereditary optic neuropathy typically begins between 15 and 35 years (range, 1 to 80 years). Painless central vision loss in one eye is usually followed weeks to months later by loss in the other eye. Simultaneous vision loss has been reported. Most patients lose vision and develop worse than 20/200 acuity. Ophthalmoscopic examination may show telangiectatic microangiopathy, swelling of the nerve fiber layer around the optic disk, and an absence of leakage onfluoresceinangiography. Eventually, optic atrophy supervenes. Some patients with Leber hereditary optic neuropathy have cardiac conduction defects. Other patients have minor neurologic abnormalities, such as a postural tremor, loss of ankle reflexes, dystonia, spasticity, or a multiple sclerosis–like illness. 