New Suture Probe Canaloplasty Combined with Suprachoroidal Collagen Implantation

Abstract Purpose To present a modified surgery technique of suture probe canaloplasty with a specially prepared monofilament 4.0 polypropylene suture combined with suprachoroidal drainage (ScD) and collagen sheet implantation for non-penetrating glaucoma surgery.MethodsProspective study with a twelve months follow-up.In order to improve suture probe canaloplasty with a more stable und smoother probing device, a standard 4/0 polypropylene suture (Prolene™ by Ethicon) (thickness: ca. 250µm) is cut and shaped with an ophthalmic knife (MANI® Crescent Knife, Mani Inc 8-3 Kiyohara Industrial Park, Utsunomiya, Tochigi 321-3231, Japan) to create a blunt end without sharp or compressed edges. Schlemm´s canal is prepared with the standard technique of canaloplasty with suprachoroidal drainage. Then instead of using the canaloplasty microcatheter or the previously published 6.0 double-helix suture - Schlemm’s canal is probed with the blunt ending 4/0 prolene suture. In case of successful 360° probing a doubled 10/0 polypropylene tension suture is thread through the 4/0 suture, which is afterwards pulled backwards and tied at its ends. Schlemm’s canal is hereby tensioned with these 10/0 sutures. A special collagen sheet (Ologen®) is placed in suprachoroidal space, and the scleral flap is firmly sewed.Results115 eyes were included in this prospective study. In 113 cases the Schlemm´s canal could completely be probed with the suture and canaloplasty with ScD and collagen sheet implantation succeeded. In two cases the intervention was transformed to 360° suture trabeculotomy due to an intraoperative cheese-wiring. Twelve months after successful new suture probe canaloplasty with ScD and Collagen Implantation the IOP had decreased by 37.1% (from 21.6±6.0 mmHg with 3.3 different IOP lowering eye drops to 13.5±3.5mmHg with 1.0 eye drops). 16 Patients did not achieve sufficient IOP levels and underwent 360° suture trabeculotomy during the follow-up. One patient had to be treated with further glaucoma surgery to achieve a sufficient IOP level.Complications were hyphema, postoperative IOP elevation and transient hypotony. No serious or sight-threatening complications occurred.ConclusionNew suture probe canaloplasty with ScD and collagen sheet implantation yields the opportunity to conduct a cost-effective canaloplasty easier and less complicated than with the previously described method with the twisted 6/0 suture. The safety profile and IOP lowering effect is comparable. In cases where complete probing fails, there is still the opportunity to switch to suture trabeculotomy over the majorly probed part of Schlemm´s canal. The pressure lowering effect of the deep sclerectomy with ScD and suprachoroidal collagen sheet implant seems to have an additional impact on the sufficient pressure lowering procedure.