Prism Adaptation Test (PAT) in the Surgical Management of Acquired Esotropia

Abstract

To the Editor. —I read with great interest the article published by the Prism Adaptation Study Research Group1in the September 1990 issue of theArchives. Patients with fusion and normal retinal correspondence (NRC) were eliminated from the study because they had little or no potential to benefit from prism adaptation. It has been my experience as well as that of other authors2-4that esotropic patients with NRC fusion, even bifoveal fusion (40 seconds of arc stereoacuity), can manifest a substantial angle buildup with prisms. Most, if not all, of these patients do benefit when undergoing surgery for the built-up angle.4If this group of patients had been included, a larger percentage of esotropic patients would have been found to benefit from presurgical prism adaptation test (PAT). If patients with fusion and NRC were eliminated from the study at the start, and the responders were patients who