Familial Optic Atrophy with Negative Electroretinograms

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.