Comparison of the anterior chamber angle structure between children and adults.

PURPOSE: To investigate the anterior chamber structure in children and adults with a similar axial length (AL).

METHODS: A total of 50 children (mean age, 7.1 ± 3.3 years; range, 3-16) with mainly refractive error and 50 adults (mean age, 73.7 ± 7.8 years; range, 50-85) with short AL were included. The mean AL was 22.21 ± 0.88 mm (range, 20.67-23.97 mm) in children; 22.34 ± 0.53 mm (range, 20.50-22.96 mm), in adults. The corneal curvature, spherical equivalent, AL, central corneal thickness (CCT), inter-scleral spur distance, perpendicular distance, anterior chamber depth (ACD), angle opening distance (AOD), and lens vault were measured. An independent t test and a stepwise regression analysis were used to analyze the data.

RESULTS: There were no significant differences between groups in AL, spherical equivalent, and perpendicular distance. By comparison, the children had larger corneal curvature (children:adults = 7.70:7.40 mm), longer inter-scleral spur distance (11.65:11.20 mm), greater CCT (560:522 μm), deeper anterior chamber (3.05:2.53 mm), and larger AOD (0.56:0.37 mm) than adults (all P < 0.01). The lens vault was smaller in the children than in the adults (0.04:0.54, P < 0.01). The predictive factors for lens vault were the ACD (coefficient = -0.407), inter-scleral spur distance (0.307), AOD (-0.650), group (children, -0.108) and corneal curvature (-0.214). The predictive factors for the AOD were the lens vault (-0.310), inter-scleral spur distance (0.140), and corneal curvature (-0.143).

CONCLUSIONS: In our cohort, the anterior chamber angle (the semicircle structure of the anterior segment) in children was larger than in adults. This may partially explain why, despite having a short AL, children rarely develop primary angle closure.