Abstract: To study the changes in anterior chamber configuration by panoramic ultrasound biomicroscopy. Phacoemulsification and IOL implantation were performed in 40 eyes in 40 cases with co-existing CACG and cataract and 40 eyes of 40 controls with age-related cataract. The anterior chamber diameter and Anterior Chamber Depth (ACD) were measured with panoramic ultrasound biomicroscopy before and 2 months after the surgery. The anterior chamber diameter in patients with CACG and co-existing cataract was 9.93±0.39 mm before surgery and 11.45±0.53 mm after surgery. The corresponding values found in controls were 11.47±0.62 mm and 11.93±0.39 mm. In both groups, the anterior chamber diameter was widened significantly 2 months after surgery and the ACD was deepened. Anterior chamber diameter in patients with CACG and co-existing cataract is less than that in patients with age-related cataract. After phacoemulsification and IOL implantation, the anterior chamber diameter is increased.