[Clinical and electrophysiological studies on posterior retinitis pigmentosa]

On the basis of fundus appearance and angiographic fundus pictures, 48 cases of posterior retinitis pigmentosa were divided into pericentral type (20 cases), perimacular type (21 cases), and macular type (7 cases). We compared the 3 groups clinically and electrophysiologically. Visual acuity and visual field were progressively deteriorated in half of the cases of pericentral type two years after the initial visit. The waveform of flash electroretinogram (ERG) was negative in the pericentral type, subnormal in the perimacular type, and normal in the macular type. These ERG findings suggest that the rod function was more severely damaged in the pericentral type than in the other types. Contrary to the ERG findings, the pattern-evoked cortical potential was normal in the pericentral type, and we assumed there is less damage of the foveal function in the pericentral type.