The electrooculogram in heterozygote carriers of Usher syndrome, retinitis pigmentosa, neuronal ceroid lipofuscinosis, Senior syndrome and choroideremia

Electrooculographic studies were performed in 77 carriers of tapetoretinal dystrophies: Usher syndrome (20), retinitis pigmentosa (32), neuronal ceroid lipofuscinosis (6), Senior syndrome (2), and choroideremia (17). The carriers were matched for sex and age with normal controls.In carriers of Usher syndrome the eog Lp/Dt ratio was significantly lowered with 30% of the recordings having a subnormal value. There was a trend in carriers of retinitis pigmentosa to a subnormal eog. In contrast to previous studies there was no decrease in the eog Lp/Dt ratio in carriers of neuronal ceroid lipofuscinosis. Two carriers of Senior's syndrome had a normal eog. Carriers of choroideremia did not differ significantly from normal controls; however, the Lp/Dt ratio decreased with increasing age.An abnormal eog may be indicative of the carrier state in relatives of patients with tapetoretinal dystrophies.