Preoperative prism adaptation for acquired esotropia: Long-term results

Purpose: The efficacy of preoperative prism adaptation in subjects with acquired esotropia has been established at 6 and 12 months postoperatively. We evaluated the outcomes of subjects with acquired esotropia who had preoperative prism adaptation and were followed longer than 12 months. Methods: A retrospective analysis was undertaken of 2 groups of subjects with acquired esotropia who underwent bilateral medial rectus recessions based on the distance angle of deviation and were followed more than 12 months postoperatively. Group A subjects had preoperative prism adaptation to determine the target angle for corrective surgery. In Group B subjects, surgery was based on the maximum angle of strabismus at distance, determined by alternate prism cover test without preoperative prism adaptation. Results: We compared 17 subjects in Group A and 19 subjects in Group B. The postoperative follow-up period was 3 +/- 1.7 years in Group A and 4.8 +/- 1.8 years in Group B. The age at the last visit was 9.1 +/- 2 years in Group A and 10 +/- 2 years in Group B. Postoperative residual esotropia was 2.6 +/- 2.5 PD at distance in Group A patients and 6.6 +/- 5.9 PD in group B patients (P = .002). Residual esotropia at near was 3 +/- 3.8 PD in Group A and 11.5 +/- 8.12 PD in Group B (P < .01). More Group B subjects required bifocal spectacles to achieve optimal alignment at near (P = .001). Conclusion: Acquired esotropia subjects operated on for their distance prism-adapted angle maintained better motor alignment over a long-term follow-up period when compared with nonprism-adapted subjects operated on for their distance angle.