As intermittent exotropia progresses, the exotropia becomes constant, meaning it is frequently in a state of outward deviation. It can be alternating, known as alternating exotropia, or one eye may have a tendency to fixate. If the exotropia begins before visual development is complete, it may involve monocular fixation and result in amblyopia. In most patients, exotropia occurs due to decompensation of intermittent exotropia, and these patients generally do not have amblyopia.

bubble_chart Clinical Manifestations

The clinical manifestations of constant exotropia depend on its {|###|} disease cause. It may result from decompensated intermittent exotropia, or poor vision in one eye leading to exotropia, known as sensory exotropia; or in infants, delayed medical or surgical intervention, leading to a lack of fusion and gradual development of exotropia.

A comprehensive examination should be performed, measuring the angle of deviation at distance and near, checking for A-V patterns and lateral incomitance, which is crucial due to the risk of overcorrection. Additionally, assess fixation patterns, perform cycloplegic refraction, and check for amblyopia.

bubble_chart Treatment Measures

1. Correcting refractive errors: For farsightedness +2.00D to +3.00D, correction may be omitted as appropriate; for +5.00D to +6.00D, the correction may be reduced by 2–3D as appropriate. Whether it is farsightedness astigmatism or myopia astigmatism, correction should be applied.

2. Treating amblyopia.

3. Orthoptic training.

4. Surgical treatment: For children over 6 months of age with constant strabismus, surgical treatment should be performed. The primary goal is to restore binocular single vision as much as possible. If one eye has amblyopia and the establishment of binocular vision is unlikely, the purpose of surgery is merely cosmetic, and no other preoperative treatments are necessary. As age increases, the tendency for exotropia to worsen may arise, and surgery can be performed after the age of 12.