Comparison of simultaneous prism and cover test (SPCT) with prism and alternate cover test (PACT) measurements with final power of press-on prism power dispensed

Abstract

Diplopic patients with smaller angles of misalignment are often treated with Press-On membrane prism, and sometimes will report failure with prism treatment. One possible explanation is that the prism power was greater than the manifest deviation with correction provided for the deviation measured by prism alternate cover test (PACT). This study explores the association of strabismic angle obtained by simultaneous prism and cover test (SPCT) and PACT with the power of Press-On prism used in adults with symptomatic strabismus.