Histological Biocompatibility of a Stainless Steel Miniature Glaucoma Drainage Device in Humans: A Case Report

Abstract

The purpose of this study was to evaluate the histological biocompatibility of a stainless steel miniature glaucoma drainage device. Twenty-four months before death due to heart failure, this seventy-three-year-old female patient underwent filtration surgery for primary open-angle glaucoma uncontrolled in the right eye. The device was implanted at the limbus under a scleral flap. For histopathological evaluation, two corneoscleral specimens were embedded in methacrylate blocks sectioned to a thickness of 50 microns, polished and stained with periodic acid schiff. Some sections included a longitudinal cross-section of the implant. At the interface between the spur and the flange of the device and the cornea, there was a small shoulder of fibrous tissue. A thin, fibrous capsule covered the remainder of the body of the device up to the distal tip. No inflammatory cells occurred within the fibrous capsule. No material or blockage was noted within the lumen. Our results support the biological inertness of the device.

Prospective Randomized Study Comparing Combined Phaco-ExPress and Phacotrabeculectomy in Open Angle Glaucoma Treatment: 12-Month Follow-Up

“…The ExPress mini glaucoma shunt implantation was proposed as a less-invasive procedure, with lower rate of complications resulting from postoperative hypotension. de Feo et al reviewed postoperative test results in patients after the ExPress mini glaucoma shunt implementation and noted that the IOP decrease is comparable to the gold standard, that is, trabeculectomy, and emphasized lower risk of intra- and postoperative complications after the ExPress shunt implantation [ 13 ]. The ExPress mini glaucoma shunt is also used in eyes with advanced glaucoma, where it is necessary to maintain the target intraocular pressure at the lowest possible level [ 3 ].…”

Ex-PRESS Implantation versus Trabeculectomy in Open-Angle Glaucoma: A Meta-Analysis of Randomized Controlled Clinical Trials

“…In recent years, Ex-PRESS has been introduced as an alternative to trabeculectomy. Numerous studies have reported on the biocompatibility, safety, and efficacy of Ex-PRESS during its evolution over the last decade [18] – [20] . However, trials have usually shown conflicting results, making it difficult to draw conclusions.…”

Comparison of trabeculectomy and Ex-PRESS implantation in fellow eyes of the same patient: a prospective, randomised study

“…29 Numerous studies have reported on the biocompatibility, safety, and efficacy of the Ex-PRESS glaucoma filtration device during its evolution over the last decade. [30][31][32][33] The device is essentially a trans-scleral miniature tube that delivers aqueous from the anterior chamber to the sub-scleral and sub-conjunctival spaces (similar to trabeculectomy). Ex-PRESS implantation under a scleral flap may be viewed as a compromise between trabeculectomy and non-penetrating glaucoma surgery on account of the standardised flow restriction imposed by the miniature shunt.…”