Abstract
Purpose:
The purpose of this report is to characterize the change in contrast sensitivity using a commercially available technique in patients with INS before and after eye muscle surgery.<br />
Methods:
This is a prospective, case series using the CSV-1000ER (VectorVision) contrast sensitivity (CS) test performed binocularly, with best corrected acuity, under office lighting (~85.0 candelas [cd] m2), before and 6 weeks after eye muscle surgery for nystagmus. The CS values are documented in log units. Sensitivity levels at each frequency ranged from 0.70 to 2.08 (3 cpd), 0.91 to 2.29 (6 cpd), 0.61 to 1.99 (12 cpd), 0.17 to 1.55 (18 cpd) log units. The Friedman test was used to evaluate the differences in the CS before and after surgery. The correlation between the absolute change in CS against the change in visual acuity was also evaluated using the Spearman correlation coefficient (r).<br />
Results:
25 patients with INS patients aged 12-55 years are included in this report. The INS patients’ best binocular acuity ranged from 20/125 to 20/30. Associated sensory system deficits included albinism, strabismus, amblyopia, and optic nerve dysplasia and retinal dystrophy. There was a statistically significant increase in CS at 6 weeks after surgery (P< .0012). There was no correlation between in visual acuity changes after surgery and the improvement in CS (r=.49, P=.10).<br />
Conclusions:
INS patients with or without sensory system deficits display deficiencies in CS function which improves after eye muscle surgery independent of changes in high spatial frequency acuity. Enhanced CS may explain the subjective improvement in vision patients report after eye muscle surgery for nystagmus. CS may have potential as a primary clinical outcome measure in interventional trials in patients with INS.