Pupillary response dynamics of mydriasis measured with multifocal pupillography.

Abstract

Purpose : Multifocal pupillography is potentially limited by the need for mydriasis for ocular examinations. We examined the time course and pupil response dynamics of mydriasis.

Methods : Normal participants were confirmed by a slit-lamp exam, Matrix visual fields, macular and retinal nerve fibre layer OCT. Pupil responses of 26 participants were recorded with video cameras under infrared illumination. The stimuli extended form fixation to ±30°, shown at 150 cd/m² on a 10 cd/m² background. The dichoptic stimuli comprised 44 independent stimulus regions/eye with a mean stimulus interval of 4 seconds/region. Predilation mfPOP was done, followed by post-dilation tests at 1, 2, 4, 6, 8, 12, 24 and 48 hours. A linear mixed effects model was fitted to contraction amplitudes and time to peak responses to determine the independent effects of mydriasis on mfPOP.

Results : Significant extra delays were recorded at 2 hrs post dilation (15.8 ± 1.2 ms, P < 0.00001). Response delays peaked at 4 hrs (31.0 ± 1.1 ms, P < 0.00001) and thereafter quickened towards baseline delays at 24 hrs. Amplitudes were more affected than delays with significant losses presenting at 4 hrs (4.0 ± 0.18 dB, P < 0.00001). Pupil response amplitudes increased towards baseline after 24 hrs, however amplitudes rebounded to significant losses at 48 hrs.

Conclusions : Pupillary response dynamics to mydriasis demonstrated that amplitudes were more affected than response delays and peaked at 24 and 4 hrs, respectively and did not recover to baseline until 48 and 12 hrs.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.