Long-term surgical outcomes of preoperative prism adaptation in patients with partially accommodative esotropia

To determine the long-term surgical outcomes of preoperative prism adaptation test (PAT) in patients with partially accommodative esotropia.

PAT was performed for the remaining esotropia after full correction of hyperopia. Prism adaptation (PA) responders were defined as patients with stable esodeviation between 0 and 8 prism diopters (PD) while developing sensory fusion throughout the prism adaptation period. Surgical success was defined as a deviation within 8 PD of both the far and near deviation angles at the last follow-up examination.

Of the 102 patients, 43 (42.2%) were PA responders, and 59 were PA non-responders (57.8%). After a mean follow-up duration of 6 years after surgery, the surgical success rate was significantly higher in PA responders (76.7% vs. 54.2%, p = 0.023). By multivariate analysis, good stereoacuity at near before surgery significantly correlated with successful outcomes after surgery (p = 0.001, β = 4.466). The risk factors of undercorrection were preoperative esotropia >35 PD (OR 3.067, p = 0.041), and preoperative hyperopia >+5.25 diopters (OR 3.099, p = 0.049). Among undercorrected patients, the annual decrease of esodeviation was significantly greater in PA responders (p = 0.043).

PA responders showed a better long-term success rate than in PA nonresponders. Patients with high hyperopia and large esotropia had a higher risk of undercorrection. Undercorrected patients eventually achieved good motor outcome with postoperative prism correction if they were PA responders before surgery.