Prism adaptation versus conventional orthoptic measurement for symptomatic esophoria: a retrospective study

Purpose: Symptomatic esophoria (SE) is a latent esodeviation that progresses into a manifest esotropia, causing substantial discomfort such as diplopia, headaches, and asthenopia. Surgery for esophoria is prone to undercorrection, necessitating repeated interventions. Addition of preoperative prism adaptation testing (PAT) reveals significantly larger angles of deviation (AOD). The aim of this retrospective study was to compare rates of repeated surgical interventions in SE patients with or without PAT as a supplement to standard orthoptic evaluation. Methods: We reviewed records of patients with SE who underwent surgery at the Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark, from January 1, 2017, to August 31, 2023. We collected information on whether PAT was conducted, demographics, and medical and ophthalmological history. Primary outcome was the need for repeated intervention either by reoperation or by postoperative adjustment of sutures. Results: One hundred and five SE patients were included, with 61 in the non-PAT group and 44 in the PAT group. Repeated surgical interventions were less frequent in the PAT group (23%) compared to the non-PAT group (48%) (P 0.009). PAT resulted in an increase in median AOD at near and distance by 14PD and 16PD, respectively (p < .001 and p < .001). Conclusions: In this observational study, SE patients undergoing PAT had significantly lower rates of repeated surgical interventions and a significant increase in baseline AOD, compared to those who did not undergo PAT.