The optic nerve connects the eye to the brain and carries visual signals from the retina that enables us to see. Consequently, any disease that damages this nerve can result in vision loss. A number of gene mutations lead to defects of such nerve conduction which may begin with damage to the nerve cells of the retina. The optic nerve appears pale (atrophied).
The clinical disease is highly variable among patients. Visual symptoms and hearing loss may have a subtle onset in early childhood. Loss of vision is progressive. Eye movements may become restricted and there are often associated neurological symptoms such as unsteadiness, muscle cramps, and stiffness in walking. The eyelids may appear to droop and some patients are nearsighted.
The inheritance pattern is autosomal dominant with affected parents passing on the disorders to their children with a 50% probability for each child.
The diagnosis is most likely made by an ophthalmologist in consultation with a neurologist. A full evaluation is necessary since there are other conditions, both ocular and neurological, with similar features. No treatment for the neurological disease is available but visual functioning can be improved with the help of low vision devices. Little is known about the natural history of this condition and its impact on longevity.