An example of ragged red fibers It is important to differentiate<unk>  from other pathologies that may cause an<unk> . There are specific therapies used for these pathologies.<unk>  is diagnosed via muscle biopsy. On examination of muscle fibers stained with Gömöri trichrome stain, one can see an accumulation of enlarged mitochondria. This produces a dark red staining of the muscle fibers given the name “ragged red fibers”. While ragged red fibers are seen in normal aging, amounts in excess of normal aging give a diagnosis of a mitochondrial myopathy.Polymerase chain reaction (PCR), from a sample of blood or muscle tissue can determine a mutation of the mtDNA. Elevated acetylcholine receptor antibody level which is typically seen in myasthenia gravis has been seen in certain patients of mitochondrial associated<unk> . It is important to have a dilated eye exam to determine if there is pigmentary retinopathy that may signify Kearns–Sayre syndrome which is associated with cardiac abnormalities. MRI may be helpful in the diagnosis, in one study volumes of medial rectus, lateral rectus, and inferior rectus muscles in<unk>  were not smaller than normal (in contrast to the profound atrophy typical of neurogenic paralysis). Although volumes of the superior rectus muscle-levator complex and superior oblique were significantly reduced.
Chronic progressive external ophthalmoplegia
Subacute myelo-optic neuropathy
Recurrent painful ophthalmoplegic neuropathy
Positional alcohol nystagmus
Ocular myasthenia
Central facial palsy
Progressive bulbar palsy
Corneal-cerebellar syndrome