The effect of pupillary dilatation on visual field testing in glaucoma

Abstract

Introduction The concern on the effect of pupillary dilatation on visual field parameters in patients with glaucoma comes from the fact that patients usually seek field examination after their pupils have been dilated for fundus examination. Aim To investigate the influence of pupillary dilatation on visual field testing in patients with glaucoma, by using automated static perimetry. Patients and methods A prospective comparative noninterventional clinical study was conducted on 20 eyes (11 patients) with open-angle glaucoma. Two consecutive visual field examinations were performed on each eye of all participants. The first was done on the undilated normal pupil size, whereas the second was done after dilating the pupil to 6–8 mm. Results After pupillary dilatation, fixation losses were significantly higher. There was no significant difference in false-negative or false-positive results. There was improvement in the mean deviation with no statistical significance. Pattern standard deviation showed also improvement, which was statistically significant. Discussion and conclusion It was found that pupillary dilatation caused variability and difference in the visual field parameters, which emphasizes the importance of consistent pupillary size in performing the serial automated visual field tests, especially in patients with glaucoma to allow standardized judgment on the patient’s progression.