Purpose: A role of the choroid has been suggested in the pathophysiology of angle closure. We assessed the choroidal thickness (CT) in Caucasian patients with primary angle closure (PAC) and in a subgroup of patients with plateau iris using swept-source optical coherence tomography (SS-OCT) compared to normal eyes.
Methods: This prospective cohort study in a hospital-based population in a tertiary center compared consecutive patients with PAC to healthy controls. A subgroup analysis of patients with plateau iris was also performed. Choroidal thickness was measured by SS-OCT in the subfoveal area (SFCT) and at 1- and 3-mm eccentricity superiorly, inferiorly, nasally and temporally from the fovea.
Results: Compared to the 25 eyes of 13 control patients [7 women, mean (SD) age, 56.6 (15.7) years], the 45 eyes of 25 patients with PAC [15 women, mean (SD) age, 55.7 (10.7) years] had a significantly increased SFCT. SFCT was 355.36 μm (SD 85.97) in PAC eyes versus 286.08 μm (SD 98.09) in control eyes (p = 0.009). The CT was also significantly increased compared to control eyes in other macular areas (p < 0.05), except at 3 mm temporal to the fovea. In the plateau iris subgroup, a not significant (except 3 mm nasal to the fovea) trend toward an increased CT was observed in all studied macular areas compared to control eyes.
Conclusion: In eyes of Caucasian patients with PAC, the CT is increased compared to controls. Increased CT could contribute to the pathophysiology of PAC with a possible choroidal expansion and dysfunction of choroidal ganglion cells.
Keywords: Angle closure; Choroidal thickness; Glaucoma; Optical coherence tomography.