Abstract
Purpose :
In conventional visual field testing, a subject has to occlude one eye during testing, However, on a head-mounted perimeter such as the imo® it is possible to conduct perimetry assessment under binocular conditions, i.e. without occlusion. It has been previously reported that pupil diameter is smaller under binocular testing conditions when compared to monocular testing. The visual field sensitivity significantly decreases if the pupil diameter is less than 2mm. The difference in pupil size also may alter contrast sensitivity and aberration.
We conducted perimetry testing with the imo® head-mounted perimeter, and investigated the difference in pupil area and diamiter between monocular and binocular testing conditions.
Methods :
Twenty-two subjects with glaucoma (34.8±7.3 y.o.) underwent visual field testing using imo® 24plus (1-2) AIZE examination. A pupil image was taken each time a test target was presented, and the pupil diameter was measured. We compared the pupil diameter between monocular and binocular testing conditions. Furthermore, 10 healthy volunteers (53.1±11.0 y.o.)underwent visual field testing using a single 20dB intensity custom program. A CMOS sensor built into the imo® was used to image the pupil at 300 fps, and the pupil area and diameter were analyzed using ImageJ software. We compared the average pupil area and diameter of each subject between the monocular and binocular testing conditions.
Results :
During 24plus(1-2) examinations, the average pupil diameter with one eye occluded and without eye occlusion was found to be 4.1±0.8mm and 4.6±1.1mm respectively (p<0.05). During testing for healthy volunteers, the average pupil area and diameter in binocular testing were 13.3±3.6 mm2 and 4.2mm. The average pupil area and diameter in monocular testing were 22.0±7.6mm2 and 5.3mm. Under monocular testing conditions, the pupil area was significantly larger than binocular testing (p<0.05). Therefore, these results suggest that the pupil area difference in monocular and binocular testing conditions might not affect imo® testing results.
Conclusions :
There was a 28% difference in pupil diameter between monocular and binocular testing using the imo® head-mounted perimeter.
This is a 2020 ARVO Annual Meeting abstract.