Morphological findings in retinitis pigmentosa with early diffuse rod dysfunction.

The retina from the postmortem donor eye of a 64-year-old man with advanced autosomal dominant retinitis pigmentosa (RP) was studied with light and electron microscopy. Two children of the donor were tested with two-color, dark-adapted static perimetry and found to have Type 1 or D-type RP, the psychophysical subtype with early onset of severe rod dysfunction diffusely affecting the entire retina. In the macula of the donor retina, rods and cones were clustered in irregularly shaped patches, in association with pigmented retinal pigmented epithelial cells. Only cones in the middle of these patches possessed outer segments, and these were poorly organized. Of the few photoreceptors remaining outside of the macula, those in the superior retina had well-formed terminals and appeared to be rods. Rods were also observed superior to the disk and in the temporal mid-periphery. The few photoreceptors remaining in the inferior retina were also rod-like, but had less well-formed terminals. The retinal pigmented epithelium was relatively normal near surviving photoreceptors, but was depigmented, had thinned, or was absent in regions of photoreceptor dropout. These findings represent the first reported morphology of the retina from an eye donor with known psychophysical subtype of RP.