Evaluation of Anterior Segment Changes After Laser Peripheral Iridotomy and Trabeculectomy in Primary Angle Closure Glaucoma Using Sirius Scheimpflug Imaging

Purpose: To evaluate changes in anterior segment morphology following laser peripheral iridotomy (LPI) and trabeculectomy in primary angle closure glaucoma (PACG) using Sirius Scheimpug imaging. Methods: In this prospective study, PACG patients undergoing LPI and trabeculectomy were imaged pre- and post-procedure using the Sirius Scheimpug system. Anterior segment parameters including anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), iris curvature (I-Curv), and lens vault (LV) were analyzed and compared. Results: 72 eyes of 36 PACG patients were analyzed. At 1 month post-LPI, there was signicant widening of ACA (p<0.001), attening of I-Curv (p=0.002), and lowering of LV (p<0.001) with no change in ACD or ACV. After trabeculectomy, ACD and ACV increased signicantly (p<0.001), along with further ACA widening (p=0.03) and I-Curv attening (p=0.01). LV remained reduced. Conclusions: Sirius imaging allows quantitative assessment of anterior segment changes after LPI and trabeculectomy in PACG. LPI induced morphologic changes consistent with iris prole attening and angle widening. Trabeculectomy additionally increased anterior chamber depth and volume. Scheimpug imaging enables understanding of biomechanical effects of glaucoma surgery.