Bilateral Occlusion Reduces the Ocular Deviation in Intermittent Exotropia.

摘要: Purpose The most common form of strabismus, intermittent exotropia, is thought to become manifest when the drive fuse overcome by excessive divergent muscle tone. This principle tested examining alignment eyes in absence vision. We compare ocular deviation patients with exotropia under conditions monocular versus binocular occlusion. Methods prospective study a patient cohort referred our laboratory enrolled 18 typical findings well-controlled exotropia. Eye positions were recorded video eye trackers while looked at fixation spot distance 57 cm. One was occluded, and resulting measured. Both then re-measured. Results majority (11/18) had smaller both covered. Occlusion one resulted mean 13.5° ± 4.7°. reduced 6.0° 6.5° (paired t-test, P < 0.001), corresponding 56% reduction deviation. persisted during prolonged bilateral occlusion but reversed as soon vision restored. Conclusions Bilateral reveals fixation-free state that different from orthotropia usually less than occurs spontaneously viewing. finding demonstrates angle actively mediated visual feedback, which fixating capable providing alone.