RESUMO
The prism adaptation test (PAT) is a preoperative tool that may fine-tune surgical dosage and reduce under- and overcorrection in pediatric partially accommodative esotropia; however, it is resource intensive and the benefits are uncertain. PAT involves correction of esodeviation with prisms, with subsequent assessment for and quantification of change in angle of esodeviation, thereby augmenting the surgical target angle in a subset of patients. We evaluated PAT response and postoperative outcomes in a cohort of children who underwent bilateral medial rectus recession and found that 36% of patients showed a requirement for increase of prism dosage to retain orthotropia during PAT; these patients did better than those whose deviation was stable, with postoperative rate of motor success (defined as ≤10Δ esotropia) of 100% versus 56%. PAT may be a useful positive prognostic test, and it also identifies a substantial patient population who may avoid undercorrection, the prism builders. However, this cohort may do better postoperatively regardless of the target angle for surgery. Additional randomized studies are required to demonstrate definitive benefit of PAT. Identification of the builder phenotype prior to commencing adaptation may reduce the workload involved in the PAT technique.