|The left optic nerve and the optic tracts.|
Optic atrophy is the loss of some or most of the fibers of the optic nerve. In medicine, "atrophy" usually means "shrunken but capable of regrowth", so some argue that "optic atrophy" as a pathological term is somewhat misleading and use "optic neuropathy" instead.
The optic nerve is part of the brain and has no capability for regeneration. Hence, there can be no recovery from optic atrophy and the term may refer to serious or mild, but always irreversible visual loss due to damage to the optic nerve. Three types of degeneration is seen trans synaptic , anterograde, retrograde.
Optic atrophy can be congenital or acquired.
If congenital, it is usually hereditary with an onset of deterioration in childhood and may be accompanied by nystagmus. Leber's Hereditary Optic Neuropathy, (LHON) or Leber Optic Atrophy is hereditary, but typically has its onset in 20-30 year old males. This is due to a mutation of the mitochondrial genome and hence is passed exclusively through the mothers.
Alternatively, congenital optic atrophy can be caused by a lack of oxygen during pregnancy, labour or in the early days of a child's life. Some drugs taken during pregnancy are also associated with optic atrophy.
The acquired type of optic atrophy may be due to blood supply changes in the eye or optic nerve (anterior ischemic optic neuropathy or posterior ischemic optic neuropathy), may be secondary to inflammation or swelling within the optic nerve (optic neuritis), may be a result of pressure against the optic nerve (such as from a tumour), or may be related to metabolic diseases (e.g., diabetes mellitus), trauma, glaucoma, or toxicity (caused by methanol, tobacco, or other poisons). It is also seen in vitamin B12 deficiency and Paget's disease of the bone.
- International Foundation for Optic Nerve Disease
- Leber's Hereditary Optic Neuropathy Trust
- Vision Support Guide