Daniel R. Gold, DO, Departments of Neurology, Ophthalmology, Neurosurgery, Otolaryngology - Head & Neck Surgery, The Johns Hopkins School of Medicine
Three patients are presented here, each with poor vision (counting fingers or worse) related to retinitis pigmentosa in one patient (Usher's syndrome) and optic neuropathy in two patients, each of whom developed pendular nystagmus after vision loss developed. Visually mediated movements normally prevent the eyes from drifting away from a target, and afferent inputs are needed to calibrate eye movements. Especially in the two optic neuropathy patients who had neurologic involvement, multiple possible mechanisms for the nystagmus exist, 1) vision loss resulting in delayed response time for visual processing, and 2) the possibility of an unstable neural integrator from brainstem involvement.
Spencer S. Eccles Health Sciences Library, University of Utah