Effects of Mydriasis with 1% Tropicamide on Goldman I Microperimetry

Background. Microperimetry is a visual field test that examines the fundus to test retinal sensitivity by correlating retinal structure and function. Currently, there are no clear guidelines on whether the test should be done before or after pupil dilation. Interestingly, not many studies have investigated the link between pupil dilation on microperimetry performance. The purpose of this study was to investigate the effects of mydriasis on microperimetry performance. Objectives. It was assessed how dilated and un-dilated pupil impact microperimetry performance, threshold sensitivity and fixation. It was also investigated how mydriasis impacts static stimuli in microperimetry. Additionally, how demographical variables such as eye color may affect microperimetry outcomes in dilated eyes. Methods. 24 participants with healthy eyes participated in within-subject experiment. 1% tropicamide was administered in one eye and the other eye was left untreated. Both eyes were tested with microperimetry before and after the treatment. Pupil size, perimetry scores, fixation stability, false negative (FN) and false positive scores (FP) were recorded. Results. The pupil size did not show significance impact on the microperimetry performance. Fixation stability was "very stable" before and after the treatment. There was a significant difference in before treatment group between the control and treated eye. FN and FP scores were within the acceptable limits. Eye color had no impact on microperimetry performance in dilated eyes. Conclusions. The study shows that mydriasis has no significant impact on microperimetry performance. Healthy individuals may safely be tested with microperimetry pre-dilated or un-dilated, based on clinicians' evaluations