[ERG and VECP in chronic progressive external ophthalmoplegia]

Eleven patients suffering from chronic progressive external ophthalmoplegia (CPEO) were examined by means of electroretinography (ERG) and the visually evoked cortical potential (VECP) with flash and checkerboard-reversal stimuli. One patient exhibited a Kearns-Sayre syndrome, and in two patients fundoscopy revealed pigmentary retinopathy; the fundi of the other 8 patients were normal. In 3 of the patients with pigmentary retinopathy the ERG was slightly disturbed or normal, the P100 latency in the VECP being normal. In three out of 8 patients without retinal pigmentary changes the ERG indicated retinopathy. In 2 cases this was the only finding offering an explanation for the reduced visual acuity. One patient exhibited a considerably prolonged P100 latency in the pattern-reversal VECP of one eye, which might have been indicative of lesions of the visual pathway associated with CPEO.