Ultrastructural Findings in an Autopsy Eye From a Patient With Usher's Syndrome Type II

Abstract

We studied an eye taken at autopsy from a 55-year-old woman with retinitis pigmentosa and partial deafness (Usher's syndrome type II). Two years before her death, her visual acuity was R.E.: 20/80 and L.E.: 20/50, and visual fields were constricted to a 30- to 40-degree diameter with a V4e white test light. Both rods and cones were present across the retina except for areas of the midperiphery; remaining photoreceptors had shortened or disrupted outer segments, or both, and some cones had inclusion bodies in inner segments. In the macula, most of the connecting cilia of photoreceptors appeared abnormal, with either extra microtubules or an apparent disruption of the nexin link between doublet microtubules. The pigment epithelium was abnormal across the eye, with diminished apical microvilli and basal infoldings of the plasma membrane. Possible mechanisms by which abnormal cilia could lead to photoreceptor cell death are considered.