Age-related distance esotropia.

PURPOSE: To describe a form of acquired esotropia occurring in older adults, which here is termed age-related distance esotropia.
METHODS: A retrospective consecutive case series of 26 patients with this condition was reviewed.
RESULTS: The patients ranged in age from 62 to 91 years old with a median age of 77 years. The distance deviation varied from 4 prism diopters (PD) ET (esotropia) to 20 PD ET, with a median angle of 9 PD ET. At near fixation, the measurements ranged from 9 PD ET' to 10 PD X' (exophoria), with a median deviation of 3 PD ET'. Ductions and versions were full, with no evidence of lateral rectus paresis. None of these patients had an obvious underlying neurologic disorder, such as tumor or stroke. Treatment consisted of prescribing the minimum prismatic correction that eliminated distance diplopia, which was then incorporated into the patients' current spectacles. This treatment successfully eliminated the symptoms in all patients. No patient in this study required surgery.
CONCLUSION: A distinctive form of strabismus occurs in older adults that is characterized by esotropia greater at distance than near fixation. The etiology of this disorder is unknown, but it is likely secondary to anatomical changes in the orbit and/or muscles associated with aging. Most patients are readily corrected by prisms but, surgical correction might be required in some cases.