Management of Exotropia
Young children with intermittent exotropia and good fusional control should be observed without surgery, while constant or poorly controlled exotropia requires treatment, starting with refractive correction and progressing to surgical intervention when conservative measures fail. 1
Initial Assessment and Monitoring
All forms of exotropia require monitoring, with treatment decisions based on frequency of deviation, fusional control, and presence of amblyopia 1. Key indicators of progression include:
- Worsening fusional control at distance and near fixation 1
- Reduction in stereoacuity 1
- Development of suppression 1
- Transition from intermittent to constant deviation 1
Amblyopia, though uncommon in intermittent exotropia, must be treated if present before considering surgical intervention. 1
Non-Surgical Management
Refractive Correction (First-Line Treatment)
Corrective lenses should be prescribed for any clinically significant refractive error causing reduced vision, as improved retinal image clarity often improves exotropia control. 1
Specific refractive management:
- Myopia: Correct even mild amounts, as myopia occurs in >90% of exotropic patients by age 20 1
- High hyperopia: Prescribe full correction in children with exotropia and ≥4.00 D hyperopia, which can result in excellent alignment 2
- Mild-moderate hyperopia: Generally avoid correction, as reducing accommodative convergence worsens exodeviation control 1
- Astigmatism and anisometropia: Correct significant amounts 1
Overcorrecting Minus Lens Therapy
For suboptimal fusional control despite refractive correction, consider stimulating accommodative convergence by 1:
- Increasing myopic correction in myopes
- Reducing hyperopic correction in hyperopes
- Prescribing myopic correction in emmetropes
Important caveat: This therapy may be effective short-term but results often are not maintained and are associated with myopic shift in children ages 3-10 years 1. Older patients and adults frequently cannot tolerate this due to visual discomfort or decreased acuity 1.
Part-Time Patching
Part-time patching (2-6 hours daily) may improve fusional control and reduce deviation angle, particularly in ages 3-10 years 1. Two randomized trials found that deterioration is uncommon with or without patching, though patching may slightly lower deterioration probability 1. Patching can be prescribed on the preferred eye or alternated between eyes 1.
Vision Therapy/Orthoptics
For convergence insufficiency (older children/teenagers with intermittent exotropia at near, reduced fusional convergence amplitudes, remote near point of convergence), vision therapy/orthoptics is effective in improving control compared to observation alone 1, 3.
Surgical Management
Indications for Surgery
Surgery should be considered when 1, 4:
- Deviation is constant or present most/all of the time
- Deviation occurs frequently and is large enough to be unacceptable
- Non-surgical treatments have failed
- Progressive worsening of control despite conservative management
Referral to a pediatric ophthalmologist is recommended when diagnosis or management is difficult, or when initial conservative measures fail. 4
Surgical Techniques
Surgical options include 4:
- Bilateral lateral rectus muscle recessions
- Unilateral lateral rectus recession with medial rectus resection
Approximately 80% achieve good alignment at 6 months postoperatively, though long-term recurrence is common even after initially successful surgery 4. Surgery reduces distance and near deviation angles, improves photophobia, health-related quality of life, stereopsis, and Newcastle Control Score 3.
Special Considerations
Infantile exotropia (rare, presenting before age 1 in healthy children) typically requires surgical correction, with 10 of 12 patients in one series requiring surgery 5. These patients can achieve good visual acuity and satisfactory alignment, though oblique muscle overaction and dissociated vertical deviation are common 5.
Sensory exotropia (associated with unilateral/bilateral vision loss) is best treated surgically with recession/resection on the impaired eye 6.
Follow-Up
Children require ongoing evaluations every 6-12 months to monitor 4:
- Deviation control
- Visual acuity
- Binocularity
Critical pitfall: The optimal therapy for exotropia, long-term benefit of early surgical correction, and relative merits of bilateral versus unilateral surgery are not well established 1. Natural history data show mixed results, with some studies reporting stability or spontaneous improvement, while others show deterioration in 28% of children ages 12-35 months and 15% ages 3-10 years over 3 years 1.