Anterior Choroidal Thickness Increased in Primary Open-Angle Glaucoma and Primary Angle-Closure Disease Eyes Evidenced by Ultrasound Biomicroscopy and SS-OCT.

Purpose: To compare the anterior and posterior choroid thickness (ACT and PCT, respectively) in primary open-angle glaucoma (POAG), primary angle-closure disease (PACD), and healthy control subjects.

Methods: A total of 29 POAG patients (56 eyes), 37 PACD patients (64 eyes), and 34 healthy volunteers (68 eyes) were enrolled in this study; 50 POAG eyes were divided into 25 early/moderate-stage and 25 advanced-stage eyes by visual field loss, while 64 PACD eyes were classified as primary angle-closure suspect (PACS), 8 eyes; primary angle closure (PAC), 18 eyes; and primary angle-closure glaucoma (PACG), 38 eyes. Ultrasound biomicroscopy (UBM) was used to measure the ACT at a distance of 4 mm from the root of iris in all participants. ACT and PCT were measured using UBM and swept-source optical coherence tomography (SS-OCT), respectively. A 4-mm distance from the iris root was self-defined as the anterior choroid that well matched the real anterior choroid.

Results: The mean ACT measured by UBM was 0.45 ± 0.057 mm in POAG eyes, 0.38 ± 0.050 mm in PACD eyes, and 0.30 ± 0.050 mm in healthy eyes. Both the POAG and PACD eyes had a thicker anterior choroid than healthy eyes (P < 0.01). Compared to early/moderate-stage eyes of POAG, advanced-stage eyes had similar ACT (P > 0.05). PACG eyes had a thinner anterior choroid than PAC/PACS eyes (P < 0.05). However, no statistically significant difference was noted for POAG, PACD, and normal control eyes' PCT using SS-OCT (P > 0.05).

Conclusions: POAG/PACD eyes had a thicker anterior choroid than the controls. However, there was no significant difference in the PCT among the groups. The anterior choroid might play a role in the pathogenesis of glaucoma, warranting further investigation.