Iris cross-sectional area decreases with pupil dilation and its dynamic behavior is a risk factor in angle closure

Abstract

PURPOSE: To estimate the change in iris cross-sectional (CS) area with pupil dilation using anterior segment optical coherence tomography comparing eyes with angle closure (AC) to open angle glaucoma (OAG). METHODS: Sixty-five patients from the Wilmer Glaucoma service, 36 with definite or suspected OAG and 29 with definite or suspected AC, underwent anterior segment optical coherence tomography imaging under 3 conditions (pupil constriction to light, physiologic dilation in the dark, and after pharmacologic dilation). The nasal and temporal iris CS areas were measured with custom software, 3 times in each of 4 meridians. The principal outcome variables were iris CS area and change in iris CS..