Fig. 14. Electroretinographic responses of four males with choroideremia. Cone flicker responses to white 30-cps flicker remained detectable in the oldest male when rod responses to blue light were not detectable. Normal responses are shown for comparison. Time of stimulus onset is designated by vertical hatched lines in columns 1 and 2 and vertical shock artifacts in column 3. Arrows and vertical bar on rod responses to blue light show range of normal b-wave implicit times. Responses to single flashes of white light show reduced a- and b-wave amplitudes in all males. Arrows on white flicker responses show delayed implicit times in the affected males. (From Sieving PA, Niffenegger AB, Berson EL. Electroretinographic findings in selected pedigrees with choroideremia. Am J Ophthalmol 1986;101:361.)