Optic atrophy 6
Overview
An early onset form of progressive optic nerve dysfunction which results in impaired vision. Vision loss progresses very slowly. The eye disorder is caused by a genetic defect (8q21-q22)
Symptoms
* Progressive vision loss * Photophobia * Red green color blindness * Pale optic disk
Causes
Optic atrophy usually results from central nervous system disorders (such as chiasmal tumors, syphilis, ischemic optic neuropathy, drugs, retinal vascular disease, or degenerative disease) or from end-stage glaucoma. Other causes include retinitis pigmentosa; chronic papilledema and papillitis; glaucoma; trauma; central retinal artery or vein occlusion that interrupts the blood supply to the optic nerve, causing degeneration of ganglion cells; ingestion of toxins, such as methanol and quinine; and deficiencies of vitamin B 12, amino acids, and zinc. There are several rare forms of hereditary optic atrophy that can affect children and young adults.
Diagnosis
isual acuity testing reveals poor vision. An afferent pupillary defect is noted when pupils are examined. Fundus examination through a dilated pupil with an ophthalmoscope shows pallor of the nerve head from loss of microvascular circulation in the disk and deposit of fibrous or glial tissue. Visual field testing reveals a scotoma and, possibly, major visual field impairment.
Treatment
Optic atrophy is irreversible, so treatment aims to correct the underlying cause and prevent further vision loss. Steroids may be given to decrease inflammation and swelling, if the cause is found to be ischemic neuropathy. If a space-occupying lesion is the cause, neurosurgery may be required. In multiple sclerosis, optic neuritis often subsides spontaneously but may recur and improve repeatedly.