Abstract
Abstract: :
Purpose: The purpose of this report is to characterize "universal" long term, clinical and electrophysiological effects of extraocular muscle in a prospective, cohort, non–comparative case series of 75 patients with INS. Methods: Outcome Measures Included: Pre– and Post–Operative Binocular Best Optically Corrected, Acuity, Anomalous Head Posture, Expanded Nystagmus Acuity Function, Null Zone Position, Null Zone Width, Foveation Time and The NEI Visual Function Questionnaire. Results: Pts were 2.5 to 61 to yrs of age, 71% male, and 68% had strabismus, 48% had a head posture, and 56% had an associated sensory system deficit. Acuity increased .1 LogMar in 71 %, .2 LogMar in 53 % and .3 LogMar in 15% of INS patients. Patients <8 years old improved more than patients > 8 years in visual acuity (P=.01), head position (P=.04), and null position (P=.002); but not for null zone width (P=.88). In those operated on for an AHP with or without associated strabismus the AHP improved significantly. The NAFX and Foveation Time measured from eye movement recordings showed persistent, significant increases in all 15 patients in whom it was measured. Twelve of fifteen adults showed significant, persistent increases in the Visual Function Questionnaire. Conclusions: This report adds to the evidence that surgery on the extraocular muscles in patients with INS has independent neurological and visual results, and as such, should be considered "neurosurgical" and well as an "orthopedic."
Keywords: nystagmus • strabismus: treatment • eye movements