The afferent and efferent visual pathways within the central nervous system
are frequently involved in mitochondrial diseases. Neuro-ophthalmic signs
figure prominently and may be the presenting or even sole manifestation of
these disorders. The four most common neuro-ophthalmic abnormalities seen i
n mitochondrial disorders are bilateral optic neuropathy, ophthalmoplegia w
ith ptosis, pigmentary retinopathy, and retrochiasmal visual loss.