A simplified technique for non-penetrating deep sclerectomy

To present a modified technique for non-penetrating deep sclerotomy (NPDS) with limited use of sharp instruments.

A special fine spatula is used to separate the Descemet membrane from stromal tissue afterpreparing superficial and deep scleral flaps and opening the Schlemm's canal. Another specially designed spatula is used to protect the membrane when excising the overlying trabecular and stromal tissue. The other steps of the surgery are identical with the original Kozlov method. The modified surgery was performed by one surgeon experienced in NPDS, and three others starting their transition to this technique under the guidance of the first. Sixty-six patients (66 eyes) with primary open-angle glaucoma (51) or pseudo-exfoliature glaucoma (15) were treated with NPDS.

Two microperforations (3%) of the Descemet membrane were the only intraoperative complications. They did not require iridotomy or any special treatment. In the early postoperative period one 2-mm hyphema was observed, and in five cases there was transient hypotony. In one other case there was a choroidal detachment, which resolved spontaneously in less than two weeks. IOP the day after surgery ranged from 5 to 13 mmHg (mean 9.6) and after one year from 10 to 22 mmHg (mean 14.6). Late complications and IOP control were similar to conventional NPDS.

These procedures performed by one experienced and three inexperienced surgeons gave satisfactory results and the modified method can be recommended for surgeons beginning nonpenetrating glaucoma surgery, and should shorten their learning curve.