Quantitative ultrasound biomicroscopy study of biometry of the lens and anterior chamber.

Purpose: To quantify the changes induced by cataract extraction (CE) in angle recess area (ARA), angle opening distance at 250 and 500 µm (AOD250, AOD500), and aqueous depth (AQD) in comparison with axial lens thickness (LT) and to reveal effects of LT and lens position (LP) on angle parameters and AQD using ultrasound biomicroscopy (UBM).

Methods: Thirty-five eyes of 35 patients (22 male; mean age 69.5 ± 7.8 years) with senile or presenile cataract who consecutively underwent cataract surgery were enrolled in this institutional study. We performed UBM examinations before and 1 month after surgery under a standard protocol. Axial images of the anterior segment and radial sections of the angle at 4 quadrants were obtained. Aqueous depth and LT were measured in immersion A-scan mode and we used UBM Pro 2000® software for the ARA, AOD250, and AOD500.

Results: Aqueous depth and angle parameters at 4 quadrants were increased significantly after CE (p<0.05). The mean LT was 4.53 ± 0.37 mm and LP was 4.96 ± 0.25 mm preoperatively. There were statistically significant correlations between LT, LP, and AQD and angle parameters preoperatively. We also determined statistically significant correlations between LT, LP, and postoperative changes in AQD and angle parameters In comparison with LT, the mean increases in AQD, ARA, AOD250, and AOD500 were 0.21, 0.014, 0.012, and 0.017 times, respectively.

Conclusions: The results suggest that LT is as a significant factor as LPon the final dimensions of the anterior chamber and angle.