ELECTRORETINOGRAMS IN MICROCEPHALY WITH CHORIORETINAL DEGENERATION

We recorded full-field electroretinograms from a family with two daughters with microcephaly and chorioretinal degeneration and a third daughter and mother with microcephaly without chorioretinal degeneration. The two siblings with inferior chorioretinal degeneration showed electroretinographic responses to 0.5-Hz white light that were reduced 60% to 70% below normal, suggesting that the loss of photoreceptor function exceeded the areas of visible atrophy. The mother and third daughter had normal electroretinograms. The two siblings, ages 12 and 21 years, had virtually the same electroretinographic amplitudes. In a second family, a man with microcephaly and inferior chorioretinal degeneration, examined at ages 9 and 23 years, also showed 60% to 70% reduction in electroretinographic responses to 0.5-Hz white light and showed no change in amplitudes over the 14-year interval. These findings suggest that the chorioretinal degeneration sometimes associated with microcephaly is stable in young adult life, although the long-term prognosis remains to be defined.