Evaluation of Pupil Fields Using a Newly Developed Head-mounted Perimeter in Healthy Subjects

The purpose of this study was to evaluate the accuracy of pupil fields and determine the normative pupillary response data by age using a newly developed head-mounted perimeter.

A total of 100 healthy subjects (age, 20 to 68 y) were enrolled. The newly developed head-mounted perimeter "imo" was used to measure the percentage pupil constriction (PPC) as response to a stimulus at all 36 test points of the visual field. Goldmann size III and V stimuli at 0, 8, and 11 decibels (dB) under 31.4, 6, and 3 apostilbs (asb) background were presented. The PPC correlations (r) of the right and left eyes were examined. Reproducibility was determined with the coefficient of variation (CV) and a Bland-Altman plot. By a simple bootstrap method, the mean PPC were analyzed as normative data in all 36 test points.

Excellent correlation between both eyes was obtained for Goldmann size V stimuli, target luminance of 0 dB, and a background luminance of 31.4 asb (r=0.83; P<0.001). From the test-retest CV peripheral areas have low reproducibility compared with central areas. With a Goldmann size V target, there was a steeper decline of the PPC from the center field to the periphery field, and the temporal field PPC was larger than the nasal field. No major differences were observed between the PPC data and the age groups by decade (eg, center 3 degrees; P=0.223-0.913).

Normative PPC data might well be useful for assessing objective visual fields with the newly developed head-mounted perimeter.