Familial optic atrophy with negative electroretinograms
R. G. Weleber and Y. Miyake
Department of Ophthalmology, Oregon Health Sciences University, Portland.
We describe optic atrophy and abnormal electroretinographic findings in
affected members from two families. Central vision failed in the second to
third decade of life. Examination findings included visual acuities of
20/20 (1.0) to 20/500 (0.4), defective color vision, mild to moderate
myopia, pericentral or centrocecal scotomas, and, in four of five patients,
optic atrophy. Dark adaptometry found elevated cone and rod psychophysical
thresholds. Bright flash electroretinograms showed normal a-wave amplitude
and markedly subnormal b-wave amplitude. Rod responses were low normal to
moderately subnormal in amplitude with normal implicit times. Photopic
electroretinographic b-wave amplitudes varied from normal to mildly
subnormal. Cone implicit times were normal. Because negative
electroretinograms are not seen with other familial optic atrophies, the
association of optic atrophy with the abnormal negative electroretinogram
configuration in these patients represents a newly appreciated genetic
disorder.