The atypical pigmentary retinopathy of Kearns-Sayre syndrome. A light and electron microscopic study.

Two postmortem eyes from a 52-year-old man with Kearns-Sayre syndrome were examined by light, scanning, and transmission electron microscopy. Prior to death, pronounced ptosis, total external ophthalmoplegia, an episodic ventricular cardiac arrhythmia, and an atypical pigmentary retinopathy characterized by "choroidal sclerosis" and pigment clumping were documented. Histopathologic examination revealed atrophy of the retinal pigment epithelium and outer retina that was most marked posteriorly. The preservation of photoreceptors appeared to mirror the health of the underlying retinal pigment epithelium. Numerous healthy appearing rods were present in the relatively well-preserved temporal retina. The pattern of photoreceptor degeneration observed in this form of "atypical retinitis pigmentosa" suggests that the primary defect may reside in the retinal pigment epithelium.