[Evaluation of preoperative prism adaptation in patients with acquired esotropia]

A prospective study was carried out of the evaluation preoperative prism adaptation in 77 patients with acquired esotropia. Sixty-three patients who showed a stable esodeviation with prisms of 10 prism diopter or less by alternate prism cover test and fusion response to the prisms were classified as prism responders and were randomly classified into two groups. Thirty-one patients of prism responders underwent surgery based on the prism adapted angle. Patients in the other 32 cases were assigned to undergo surgery for their initially measured angle. On the other hand, 14 patients who did not respond to prism adaptation underwent surgery for their preoperative measured angle of deviation. Success rates with deviations of 0 to 10 prism diopters measured 1 year after surgery by the alternative prism cover test at 5 m and with fusion on Bagolini's striated glasses test were highest (26 [84%] of 31 patients) in prism adaptation responders who underwent surgery for prism determined angle and lowest (3 [21%] of 14 patients) in the prism adaptation nonresponder who showed no fusion response to the prisms.