Abstract
INTRODUCTION: This study aimed to investigate anterior segment parameters of eyes, with anterior chamber depth (ACD) less than 2.8 mm and axial length greater than 25.0 mm. METHODS: This cross-sectional study included 180 myopic eyes of 180 consecutive patients with axial length greater than 25.0 mm. Patients were divided into low ACD (ACD < 2.8 mm, n = 56) and normal ACD (ACD ≥ 2.8 mm, n = 124) groups. Anterior segment parameters were measured using Scheimpflug imaging and ultrasound biomicroscopy. A general linear model was used to compare parameters between the two groups, after adjusting for age and spherical equivalent. RESULTS: Compared with the normal ACD group, the low ACD group had lower values for the following parameters: corneal diameter, trabecular-anterior iris surface angle, angle-opening distance at 500 μm, anterior chamber volume, anterior chamber width, anterior vault, iris thickness at 500 μm, ciliary sulcus-to-sulcus diameter, distance between cornea and sulcus, trabecular-ciliary process distance, maximum ciliary body thickness, ciliary process length, relative anterior vault, relative distance between cornea and sulcus, and relative lens position (general linear model, p < 0.05). In contrast, central corneal thickness, iris curvature, lens thickness, lens vault, and iris-ciliary angle were greater in the low ACD group (general linear model, p < 0.05). CONCLUSION: A smaller anterior segment, as well as a thicker and more anteriorly positioned lens, may correlate with shallow ACD in eyes with long axial length.