Outcomes for unilateral recession with and without prism adaptation test
Reviewed by Fiona Rowe

The aim of this study was to compare the residual deviation after unilateral medial rectus recession for patients who underwent prism adaptation test (PAT) with orthoptic measures and those that did not. This was a retrospective review of 41 patients (29 non-PAT and 12 PAT). Baseline angles at near and distance fixation were 18 and 16PD for non-PAT and 13 and 14PD for PAT; significant differences. There was no significant lateral incomitance for either group. Residual deviation was lower in the PAT than non-PAT group after last follow-up postoperatively: mean difference of 2.05 vs 4.39PD. 61% had diplopia postoperatively in the non-PAT group vs none in the PAT group. Surgical target was higher in PAT than non-PAT at 19 vs 16.5PD (non-significant) and therefore, median recession was higher at 5.5mm vs 5mm. Postoperative lateral incomitant was significantly more in the non-PAT group. Unilateral recession was typical for angles up to 20PD. PAT was therefore important as some may increase above 20PD leading to a choice for bilateral recessions. The authors state PAT is helpful in surgical planning. For unilateral recessions, the PAT group had a lower residual angle and were less prone to postoperatively lateral incomitance.

Undercorrection of symptomatic esophoria after unilateral median recession.
Hofsli M, Torp-Pedersen T, Saunte JP, et al.
STRABISMUS
2026;34(2):147–53.