The retinal manifestations of mitochondrial myopathy. A study of 22 cases
M. A. Mullie, A. E. Harding, R. K. Petty, H. Ikeda, J. A. Morgan-Hughes and M. D. Sanders
In a series of 61 patients with the morphologic and histochemical features
of mitochondrial myopathy, 22 (36%) had pigmentary retinopathy. Three
patterns of retinopathy were identified. Eighteen patients had a "salt and
pepper" type of retinal appearance, which was usually associated with good
visual function. Two had many features of retinitis pigmentosa, and two
others showed generalized loss, or atrophy, of the retinal pigment
epithelium and choriocapillaris. These last four patients had markedly
reduced visual acuities, with optic atrophy and attenuated retinal vessels.
Electroretinography and electro-oculography were performed in 11 patients.
Both rod and cone mediated electroretinographic functions were subnormal in
eight patients, while only cone mediated functions were depressed in the
remaining three. The electro-oculographic changes were variable.
