AIM: To investigate the relationship between choroidal thickness and anterior chamber segment in subjects with eyes with narrow or open-angle. METHODS: The subfoveal choroidal thickness was measured with enhanced depth -imaging optical coherence tomography and anterior chamber parameters were measured with ultrasound biomicroscopy in one eye of 23 subjects with open-angle eyes and 38 subjects with narrow-angle eyes. The mean age was 59.52 +/- 7.04y for narrow-angle subjects and 60.76 +/- 7.23y for open angle subjects (P=0.514). Multivariate linear regression analysis was performed to assess the association between choroidal thickness and narrow -angle parameters. RESULTS: There were no differences in subfoveal choroidal thickness between open - and narrow-angle subjects (P=0.231). Anterior chamber parameters, including central anterior chamber depth, trabecular iris angle, iris thickness 500 mu m from the scleral spur (IT500), and ciliary body thickness at 1 mm and 2 mm from the sclera! spur (CBT1, CBT2) showed significant differences between the two groups (P<0.05). Subfoveal choroidal thickness showed negative correlation (beta=-0.496, P=0.016) only with anterior chamber depth in the open angle group and with age (beta=-0.442, P=0.003) and 11500 (beta=-0.399, P=0.008) in the narrow-angle group. However, subfoveal choroidal thickness was not correlated with trabecular iris angle, anterior chamber depth, ciliary body thickness, or central corneal thickness in the narrow-angle group. CONCLUSION: Choroidal thickness does not differ in the two groups and has not correlated with anterior chamber parameters in narrow-angle subjects, suggesting a lack of relationship between choroidal thickness and primary angle-closure glaucoma.