In this issue of the BJO (p 44), Stalmans et al describe their clinical results of a new technique for trabeculectomy, originally described by Wells et al.¹ In this modification of the traditional trabeculectomy procedure, there are three main alterations: (1) adjustable/removable sutures are placed along each lateral side of the trabeculectomy flap for intraoperative and postoperative adjustment; (2) an anterior chamber maintainer is placed to titrate the leakage from the trabeculectomy and to wash out inflammatory debris from the anterior chamber; and (3) a standardised excision is created using the Khaw punch instrument of 0.5 mm. The overall purported advantage of these changes is reduced complications related to early postoperative overfiltration.

The modern Cairns/Watson technique for trabeculectomy^2,3 was developed, in part, to avoid the overfiltration associated with full thickness sclerostomies. Clinical studies have demonstrated lower rates of hypotony and flat chamber with the guarded filtration approach.⁴ Subsequent progress with the use of antimetabolites, such as mitomycin C (MMC) and 5-fluorouracil (5-FU), have extended the efficacy of trabeculectomy procedures.^5,6 However, these agents have also led to an increased incidence of some complications, including chronic hypotony and bleb leakage.^5–8

Despite the improvements compared with full thickness filters, trabeculectomy remains a surgery associated with relatively high rates of complications (including hypotony and shallow/flat chamber), a substantial postoperative recovery period, and significant long term failure rates.^5–8 These factors have fuelled the search for safer and more effective outflow procedures. In particular, newer surgeries have been developed to avoid the hypotony and need for bleb formation. …