Fig. 3. Electroretinogram (ERG) responses of a normal subject and four patients with sector or stationary retinal disease. Horizontal arrows (column 1) designate range of normal rod b-wave implicit times, and vertical bar defining this range [mean ± standard deviation (SD)] has been extended through responses of patients with sector retinitis pigmentosa. Responses (middle column) from patient with Oguchi disease are interrupted by reflex blinking so the latter part cannot be illustrated. Cone implicit times in column 3 are designated with arrows. (From Berson EL. Retinitis pigmentosa and allied diseases: electrophysiologic findings. Trans Am Acad Ophthalmol Otolaryngol 1976;81:659.)