Comparison of Threshold Visual Perimetry and Objective Pupil Perimetry in Clinical Patients

Abstract

In an attempt to measure the visual field objectively, we have performed pupil perimetry, by which the pupil light reflex is monitored in response to perimetric light stimuli. The purpose of this study was to ascertain whether pupil perimetry reveals defects similar to those revealed by standard threshold perimetry in patients with various diseases. An infrared pupillometer was linked to an automated perimeter to record, at each perimetric location, 76 pupil contractions, which were comparable to the test locations of the Humphrey Field Analyzer (HFA 30-2 program; Humphrey, San Leandro, CA). One hundred eighteen patients with various diseases were investigated. Ninety-one patients (77.1%) maintained a pupil area large enough (more than 10 mm2 in area) to respond adequately to focal light stimuli throughout the test. The correlation between the pupil field and the threshold visual field was subjectively judged to be good in most cases. However, pupil perimetry showed less damage than that seen in threshold perimetry in six of nine patients who had Leber's hereditary optic neuropathy (LHON). Pupil perimetry is a good method for measuring the visual field objectively and has potential for clinical use in most of the cases.