Purpose: To evaluate quantitatively, by means of ultrasound biomicroscopy (UBM), changes in the anterior segment configuration, including the ciliary processes, induced by cataract surgery in eyes with primary angle closure.
Design: Retrospective interventional case series.
Participants: Thirty-one eyes of 31 patients with primary angle closure or primary angle-closure glaucoma were treated with cataract surgery. Before cataract surgery, 10 eyes had been treated with laser peripheral iridotomy, and 1 with laser peripheral iridoplasty.
Methods: Configuration of the anterior chamber was examined by means of UBM before and at 3 months after cataract surgery.
Main outcome measures: Using UBM, anterior chamber depth (ACD), angle opening distance at points 500 mum from the scleral spur (AOD500), and trabecular-ciliary process distance (TCPD) were measured.
Results: Not only ACD and AOD500, but also TCPD, increased significantly after cataract surgery, compared with measurements obtained before surgery (P<0.001). Postoperative AOD500 was correlated significantly with postoperative TCPD (r = 0.72, P<0.001) and with the amount of change of TCPD caused by cataract surgery (Delta TCPD) (r = 0.52, P<0.01).
Conclusions: Cataract surgery attenuated anterior positioning of the ciliary processes in eyes with primary angle closure, concomitant with significant widening of the angle. Cataract surgery resulted in not only complete dissolution of lens volume and pupillary block, but also attenuation of the anterior positioning of the ciliary processes, all of which contributed to postoperative widening of the angle in eyes with primary angle closure.