Shallow Anterior Chamber After Trabeculectomy: Risk Reduction by Use of Removable Compression Sutures

PURPOSE:: To evaluate the risk of shallow anterior chamber after trabeculectomy with removable compression sutures. METHODS:: A total of 263 eyes affected by primary open-angle glaucoma that was unresponsive to medical treatments were divided into 2 groups: 126 eyes were treated with conventional trabeculectomy (group A) and 137 with a modified surgery technique using 3 removable compression 10-0 nylon sutures (group B). All the participants received intraoperative antimetabolites (mitomycin 0.04%). Increased intraocular pressure (IOP) of >14 mm Hg in the eyes of group B patients was followed by removal of compression sutures. Best corrected visual acuity, slit lamp examination, IOP, and anterior chamber depth were evaluated 1, 7, 30, 60, 90, and 180 days after surgery. RESULTS:: On the first postoperative day, 12 eyes from group A (9.5%) exhibited a shallow anterior chamber with marked hypotony and no eyes in group B showed flat anterior chamber at any control evaluation (P<0.001). The day after surgery, group A showed a mean IOP of 5.3 mm Hg (±2.02), whereas group B had a mean of 7.4 mm Hg (±2.10). At 7 days postoperation, the values for IOP were 10.95 (±1.55) and 11.7 mm Hg (±1.66) in groups A and B, respectively. One month later, mean IOP was 11.05 mm Hg (±1.08) for group A and 13.9 mm Hg (±3.26) for group B. The surgeon removed the compression sutures from all eyes with IOP>14 mm Hg (90%). The day after suture removal, mean IOP decreased to 10.45 mm Hg (±1.37). There was no significant statistical difference in visual acuity between the 2 groups at any point during follow-up (P>0.001). At 180 postoperative days the difference in mean IOP between the 2 groups was statistically significant (P<0.001). CONCLUSIONS:: The application of removable corneoscleral compression sutures during trabeculectomy reduced the risk of postoperative shallow anterior chamber and allowed for safe IOP control after the procedure giving further postoperative chance to reduce the intraocular pressure.