Search results
Results from the WOW.Com Content Network
Behr syndrome is characterized by the association of early-onset optic atrophy with spinocerebellar degeneration resulting in ataxia, pyramidal signs, peripheral neuropathy and developmental delay. [1] [2] Although it is an autosomal recessive disorder, heterozygotes may still manifest much attenuated symptoms. [3]
Optic neuropathy is damage to the optic nerve from any cause. The optic nerve is a bundle of millions of fibers in the retina that sends visual signals to the brain. Damage and death of these nerve cells, or neurons, leads to characteristic features of optic neuropathy.
There are several causes of toxic optic neuropathy. [1] Among these are: ingestion of methanol (wood alcohol), ethylene glycol (automotive antifreeze), disulfiram (used to treat chronic alcoholism), halogenated hydroquinolones (amebicidal medications), ethambutol and isoniazid (tuberculosis treatment), and antibiotics such as linezolid and chloramphenicol as well as chloroquine and the related ...
On examination the pupillary responses may be sluggish to light. One would not expect to find an afferent pupillary defect because optic neuropathies are often bilateral and symmetric. [2] The optic disc may appear mildly hyperemic with small splinter hemorrhages on or around the disc, or may appear nearly normal. Optic atrophy typically ...
The optic tract syndrome is characterized by a contralateral, incongruous homonymous hemianopia, contralateral relative afferent pupillary defect (RAPD), and optic atrophy due to retrograde axonal degeneration. [16] Causes of optic tract lesions are also classified into intrinsic and extrinsic forms.
As the initial swelling of the optic disc subsides, optic atrophy generally develops within one to two months after onset. A retrospective diagnosis of optic atrophy due to previous ischemic optic neuropathy is often possible when a small optic disc is detected in both the affected and the opposite eye, and when other tests for potential causes ...
Vision loss in dominant optic atrophy is due to optic nerve fiber loss from mitochondria dysfunction. Dominant optic atrophy is associated with mutation of the OPA1 gene [9] found on chromosome 3, region q28-qter. Also, 5 other chromosomal genes are described as causing optic atrophy: OPA2 (x-linked), OPA3 (dominant), OPA4 (dominant), OPA5 ...
Leber hereditary optic neuropathy is a condition related to changes in mitochondrial DNA. Although most DNA is packaged in chromosomes within the nucleus, mitochondria have a distinct mitochondrial genome composed of mtDNA. Mutations in the MT-ND1, MT-ND4, MT-ND4L, and MT-ND6 genes cause Leber hereditary optic neuropathy. [6]