Assessment of binocular functions in intermittent exotropia before and after surgical correction

Abstract

Background: Intermittent exotropia (IXT) is a common form of childhood exotropia. It is an exodeviation which is controlled by fusional mechanisms. Exotropia is usually preceded by exophoria, and the deviation is mostly noticed when children are tired, ill, inattentive or after long period of near work. The aim of this work was to detect if a patient with IXT had improved in binocular functions after surgical correction. Methods: This current study was carried out on 100 patients aged above 5 years old, both sexes, diagnosed with IXT. Assessment of binocular functions made through worth 4- dots test, Baglioni striated glasses test, four diopters base out prism test, titmus stereo test, TNO test and Frisby test.Results: Significant relation between motor alignement in near and in far and the fusion 6 months post-operative (p=0.001). Stereoacuity in log sec of arc, pre- and post-operative angle of deviation and worth four-dots test in far and in near showed significant difference in one week, one month, six months after operation. Preoperative stereoacuity measured by Titmus, TNO and Frisby had significant effect (P = 0.001, 0.007, 0.006 respectively). Better preoperative stereoacuity is associated with better postoperative motor outcome and alignment stability. Conclusions: Exotropia often disturbs the binocular functions. Bagolini test is less dissociative than worth four-dot test. Surgical correction of IXT causes improvement in sensory fusion. Successful motor alignment improves stereoacuity.