Suprachoroidal drainage with collagen sheet implant- a novel technique for non-penetrating glaucoma surgery.

Abstract

Our purpose was both to introduce the new technique of suprachoroidal drainage with collagen sheet implantation as a novel technique of non-penetrating glaucoma surgery and to present first results of a prospective pilot study. A superficial rectangular sclera flap of half-scleral thickness sized 4 × 4.5mm is dissected anteriorly until clear cornea. Then, a second scleral flap is created underneath the first one sized 3.5x4mm and is cut down full-thickness to the choroid exposing the suprachoroidal space. The flap is then bluntly prepared until the scleral spur is reached. Sharp dissection above the sclera spur exposes Schlemm's canal, which is located directly anteriorly. Schlemm's canal is unroofed, juxtacanalicular meshwork is peeled and the deep flap is cut off at its base. An absorbable collagen sheet (Ologen®, Dahlhausen, Cologne, Germany) is placed into the suprachoroidal space at the level of the ciliary body, and the superficial sclera flap is sutured tightly to prevent leakage. We prospectively analyzed 65 eyes that underwent suprachoroidal drainage with collagen sheet implantation. Mean reduction of intraocular pressure after 3months was 35.1% (from 21.0 ± 4.3mmHg to 13.5 ± 3.4mmHg)(p < 0.01) and after 12months 35.6% (from 21.0 ± 4.3mmHg to 13.5 ± 3.0 mmHg)(p < 0.01). The number of topical IOP-reducing medication decreased significantly from 3.5 ± 0.7 to 0.6 ± 0.9 and to 0.9 ± 1.1 after 3 and 12months, respectively (p < 0.01). No serious complications occurred. Suprachoroidal drainage with collagen sheet implantation seems to be a safe and effective surgical technique for non-penetrating glaucoma surgery that yields the opportunity of a sufficient IOP reduction for eyes unsuitable for canaloplasty.