An Insight of Intermittent Exotropia Management and Its Complications

Intermittent exotropia (XT)is an exodeviation controlled by fusional mechanisms and usually preceded by exophoria. Unlike phoria, intermittent XTspontaneously breaks into manifest XT. Intermittent XT is a common form of childhood exotropia, accounting for about 50%- 90% of all the exotropia and affecting about 1% of the general population.Once intermittent XT becomes manifest, it either remains unchanged or gradually deteriorates.Rarely,it undergoes partial disappearance. Intermittent XT is usually first observed by the parents in early childhood as a spontaneous drifting out of one eye mostly when the child is tired, sick or day-dreaming. Symptoms of intermittent XT include blurred vision, asthenopia, visual fatigue, and rarely diplopia in older children and adults. The main goal of treatment in intermittent XT is to preserve the binocular vision. Several surgical approaches have been used successfully to treat exotropia. Bilateral lateral rectus recession (BLRR), unilateral lateral rectus recession and unilateral medial rectus resection, as well as bilateral medial rectus resection (BMRR) have all been used to treat this condition. The choice of procedure classically has been based on the measured distance/near incomitance. In Lateral rectus muscle recession; By moving a rectus muscle posterior to its original insertion site and reattaching it to the sclera, the length/tension curve of the muscle is changed. It produces the effect of “weakening “the muscle’s effect on the globe. For most recessions, this effect is seen clinically only as a change in the alignment of the eye. This weakening effect probably occurs due to reduction in the distance between the origin and new insertion of the muscle, and changes in the relationship between Tenon’s capsule, the rectus muscle pulleys and the intermuscular septum.