Ultrasound Biomicroscopic Assessment of the Changes in Angle Relationships after Laser Iridotomy in Primary Angle-Closure Glaucoma

ABSTRACT

PURPOSE: To identify the essential morphologic characteristics concerned with angle closure in chronic primary angle-closure glaucoma (PACG) and to assess the changes in quantified values for angle relationships after laser iridotomy (LI) in them using ultrasound biomicroscopy (UBM). METHODS: Anterior segment imaging and quantitative assessment of angle relationships were obtained in 25 eyes of 25 patients with chronic PACG using UBM (UBM plus2000 system, Paradigm(R) Inc., Utah, USA) before and 2 weeks after LI. RESULTS: The mean anterior chamber depth (ACD), anterior chamber angle (ACA), angle-opening distance (AOD500), and trabecular-iris distance (TID) were 2.16 mm, 12.73 degrees, 0.128 mm, and 0.101 mm, respectively. All our results were significantly smaller than previously reported quantified values in normal adult. In comparison between before and after LI, ACD and iris thickness (IT) did not change significantly, whereas ACA, AOD500, AOD250, and TID all significantly increased after LI. CONCLUSIONS: Using UBM, we identified the essential morphologic characteristics concerned with angle closure in chronic PACG and quantitatively demonstrated the result of treatment based on the changes of angle relationships after LI.