A systematic review of the effectiveness of treatments in altering the natural history of intermittent exotropia

Abstract

Evidence of effectiveness of interventions for treatment of childhood intermittent exotropia, X(T), is unclear. We conducted a systematic review to locate, appraise and synthesise evidence of effectiveness, including twelve electronic databases, supplemented with hand searches and expert contact. We included randomised controlled trials, quasi-experimental and cohort studies with a comparison group examining interventions for divergence excess, simulated divergence excess or basic type X(T) in children, up to and including 18 years of age, followed for at least 6 months. Dual data extraction and critical appraisal were conducted and a narrative synthesis undertaken. Eleven studies satisfied the eligibility criteria. Seven examined the comparative effectiveness of two surgical procedures; four compared surgery with other interventions, including botulinum toxin A therapy, orthoptic exercises, occlusion, binocular vision training and watchful waiting. The evidence retrieved was of limited extent and quality with differences across studies in terms of outcome assessment and most appropriate time-point for measuring long-term outcomes. There were mixed outcomes when comparing unilateral recession/resection (R&R) with bilateral lateral rectus recession (BLR) on improving angle of deviation, which makes it difficult to recommend either surgical option with confidence. While non-surgical interventions appear less effective in terms of improving angle of deviation, they are rarely associated with adverse outcomes. Given the limited evidence base, better designed studies are required to address the question of the most effective management for treatment of childhood X(T). Importantly, consensus is required on what constitutes a successful outcome as well as agreement on how this should be measured.

Comparison of surgery versus observation for small angle intermittent exotropia

“…Intermittent exotropia is the most common form of exodeviation in childhood 1,2 , and often requires surgical intervention. Surgery is considered when there is a progressively increasing angle of deviation, increasing frequency of deviation, deterioration in binocular vision or cosmetic problems 3,4 . The basic goal of surgery is to restore ocular alignment and to preserve binocular function.…”

Longitudinal Evaluation of Eye Misalignment and Eye Movements Following Surgical Correction of Strabismus in Monkeys

“…Strabismus correction surgery is well documented in the literature and practice with varying levels of permanence. 19,20 By various accounts, approximately 40% of the subjects that undergo surgery, develop significant recurrent strabismus, and may have to undergo multiple surgeries. 21,22 Although it is not known why surgery sometimes works and sometimes does not, it is possible to speculate that both central (brain) and peripheral (muscle) factors influence the outcome of strabismus correction surgery.…”

Investigation of The Effect of Oculo-Motor Exercises in Children with Intermittent Exotropia

“…İntermittan ekzotropyanın okul öncesi çocukların yaklaşık 1/30'ini etkilediği ve altta yatan en büyük sebebin doğum sırasındaki hipoksi olduğu bildirilmiştir (2). On dokuz yaş altı çocuklarda 32/100000 oranındaki görülme sıklığı, çocukların psikososyal yönden gelişimlerini olumsuz yönde etkilemekte ve ileriki yaşamlarında kişisel ilişkiler, iş hayatı gibi konularda endişe yaratmaktadır (3).…”