Several types of comitant esotropia not associated with activation of the accommodative reflex may develop in later infancy (>6 months), childhood, or even adulthood. The causes of these acquired nonaccommodative esotropias are varied.
Basic Acquired Nonaccommodative Esotropia
Basic acquired nonaccommodative esotropia is a comitant esotropia that develops after age 6 months and is not associated with an accommodative component. As in infantile esotropia, the amount of hyperopia is not significant, and the angle of deviation is similar when measured at distance and near. Acquired esotropia may be acute in onset. In such cases, the patient immediately becomes aware of the deviation and may have diplopia. A careful evaluation is important to rule out an accommodative or paretic component. Temporary but prolonged disruption of binocular vision—such as may result from a hyphema, preseptal cellulitis, mechanical ptosis, or prolonged patching for amblyopia—is a known precipitating cause of acquired nonaccommodative esotropia. In patients with acquired nonaccommodative esotropia, fusion is thought to be tenuous, so this temporary disruption of binocular vision upsets the balance, resulting in esotropia. Because the onset of nonaccommodative esotropia in an older child may be a sign of an underlying neurologic disorder, neuroimaging and neurologic evaluation may be indicated, especially when other symptoms or signs of neurologic abnormality are present, such as lateral incomitance, deviation greater at distance than near, abnormal head position, or concomitant headache.
Many patients with acquired nonaccommodative esotropia have a history of normal binocular vision; thus, the prognosis for restoration of single binocular vision with prisms and/or surgery is good. Therapy consists of amblyopia treatment, if necessary, and surgical correction or botulinum toxin injection as soon as possible after the onset of the deviation. The Prism Adaptation Study showed a smaller undercorrection rate (approximately 10% less) when the amount of surgery was based on the prism-adapted angle.
Jacobs SM, Green-Simms A, Diehl NN, Mohney BG. Long-term follow-up of acquired nonaccommodative esotropia in a population-based cohort. Ophthalmology. 2011;118(6): 1170–1174.
Repka MX, Connett JE, Scott WE. The one-year surgical outcome after prism adaptation for the management of acquired esotropia. Ophthalmology. 1996;103(6):922–928.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.