Age-related distance esotropia--fusional amplitudes and clinical course

Age-related distance esotropia (ARDET) is a form of acquired strabismus that affects elderly patients and manifests as an esotropia greater with distance fixation. Limited information exists regarding fusional amplitudes and deficient divergence in this disorder.

In this retrospective study, patient characteristics, ocular alignment and motility, and clinical course of patients with ARDET were recorded. Fusional amplitudes were analyzed to assess whether deficient divergence was present in patients with ARDET.

Twenty patients with ARDET were identified. Median age was 77.5 years (range, 59 to 89 years) and median best-corrected visual acuity was 20/25. Median esotropia angle with distance fixation was 5.5Δ (range, 2 to 18Δ); median angle with near fixation was esotropia 2.5Δ (range, exotropia 3Δ to esotropia 13Δ). Fusional divergence amplitudes were decreased in all but two patients. The median amplitude with distance fixation was 4.5Δ for break (range, 1 to 11Δ) and 2Δ for recovery (range, 0 to 9Δ). In 5 patients, the fusional divergence amplitude was as large or larger than the esotropia angle. Most patients remained stable throughout a mean follow-up of 18 months (range, 3 to 37 months). Nineteen patients were managed with prisms. Strabismus surgery was performed in one patient.

Fusional divergence amplitude was deficient in most but not all patients with ARDET. In this study, most patients with ARDET remained stable and free of diplopia with prism treatment.