Decompensated Esophoria as a Benign Cause of Acquired Esotropia

Purpose: To determine informative clinical and magnetic resonance imaging (MRI) characteristics of patients with symptomatic adult acquired, comitant esotropia due to decompensated esophoria.

Design: Retrospective, interventional case series.

Methods: Setting: Institutional.

Study population: Patients with decompensated esophoria who developed acute acquired comitant esotropia.

Observation procedures: Ophthalmic examination, stereopsis, and strabismus measurements at distance and near using prism cover tests in diagnostic gaze positions were performed. Patients underwent high-resolution surface coil MRI of extraocular muscles with target fixation, and MRI of the brain. Strabismus surgery was performed under topical anesthesia with adjustable sutures wherever possible. Paired t testing was used to evaluate postoperative changes with 0.05 considered significant.

Main outcome measure: Clinical and MRI characteristics, and surgical outcome of patients with decompensated esophoria.

Results: Eight cases were identified involving subjects of mean age 29 ± 9.4 (range: 20-48) years having gradually progressive intermittent horizontal, binocular diplopia for 10 months to 3 years. Mean preoperative esotropia was 31 ± 12 Δ at distance and 29 ± 12 Δ at near, although this was intermittent in 5 patients who exhibited enhanced fusional divergence. Neurologic evaluation and MRI of brain, orbits, and extraocular muscles were unremarkable in all cases. Orthotropia was successfully restored in all by standard or enhanced doses of bimedial rectus muscle recession surgery, improving mean stereoacuity from 535 to 68 arc seconds, although 5 patients exhibited 2-14 Δ asymptomatic residual esophoria.

Conclusion: Decompensated esophoria is a benign clinical entity causing acute, acquired, comitant esotropia treatable with enhanced medial rectus recession.