Acute Acquired Comitant Esotropia in Adults; a Case Report

Purpose: The aim of this manuscript was to report the clinical char-acteristics of two patients suffering from acute acquired comitant esotropia presented in adulthood. Cases Report: Both patients reported intermittent diplopia especially during car driving before their diplopia becoming constant. They had 20/20 uncorrected visual acuity and a cyclorefraction of + 0.50 D with normal extraocular function except very mild lateral rectus underac-tion (< 1) in their both eyes. In alternate prism cover test, the manifest esotropia of 25 - 30 Δ was measured at both far and near distances. They did not show any signs of neurological disorders such as marked extraocular underaction or different esotropia on lateral gazes com-pared with esotropia in primary position. No abnormality was found on electromyography, visual field measurements and magnetic reso-nance imaging for both cases. Conclusion: Based on our clinical assessment, hereditary causes, mild lateral rectus underaction or inability to compensate esotro-pia due to decreased divergence amplitude and fusion could be considered as the probable risk factors for acute acquired comitant esotropia in adults, although the actual etiology of this disease has not been determined.