Comparison of Compass and Humphrey Perimeters in Detecting Glaucomatous Defects

Mean sensitivity with FAP is 1 dB lower than HFA, a finding due to different threshold strategies. Differences of global indices for FAP and HFA are small, which makes the 2 perimeters equivalent in the clinical setting. However, FAP seems more severe in evaluating glaucomatous damage, with absolute scotoma areas larger than with HFA. We raise the hypothesis that such difference may be the result of the active compensation of eye movements available with FAP.