Biocompatibility and feasibility of VisiPlate, a novel ultrathin, multichannel glaucoma drainage device

• Published in: Journal of materials science. Materials in medicine Vol. 32; no. 12; p. 141
• Main Authors: Kao, Brandon W., Meer, Elana, Barbolt, Thomas A., Lewis, Richard A., Ahmed, Iqbal Ike, Lee, Vivian, Nicaise, Samuel M., Griggs, Georgia, Miller-Ellis, Eydie G.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2021; Springer Nature B.V; Springer
• Subjects: Aluminum; Aluminum oxide; Animals; Biocompatibility; Biocompatibility Studies; Biocompatible Materials; Biomaterials; Biomedical Engineering and Bioengineering; Biomedical materials; Blindness; Ceramics; Chemistry and Materials Science; Composites; Congestion; Drainage facilities; Durability; Eye; Feasibility; Female; Fibrosis; Fluorescein; Glass; Glaucoma; Glaucoma - therapy; Glaucoma Drainage Implants; Histopathology; In vivo methods and tests; Intraocular pressure; Materials Science; Microchannels; Microelectromechanical systems; Natural Materials; Necrosis; Polymer Sciences; Rabbits; Regenerative Medicine/Tissue Engineering; Surfaces and Interfaces; Surgery; Surgical drains; Thin Films; Transplants & implants
• ISSN: 0957-4530; 1573-4838
• DOI: 10.1007/s10856-021-06613-8

Background Glaucoma is the leading cause of blindness worldwide. Glaucoma drainage devices and minimally invasive glaucoma surgeries (MIGS) often present with tradeoffs in safety and durability of efficacy. Using a rabbit model, we examined the biocompatibility and feasibility of VisiPlate, a novel, ultrathin, tubeless subconjunctival shunt comprised of a network of microchannels. Methods Six naive female New Zealand White rabbits received implants (three only in the right eye with contralateral eye untreated and three in both eyes) composed of a 400-nm-thick aluminum oxide core coated with 2 µm of parylene-C, manufactured with microelectromechanical systems (MEMS) techniques. Tonometry, slit lamp exam, clinical exam, fluorescein patency testing, and histopathology were performed. Results VisiPlate demonstrated IOP-lowering of 20–40% compared to baseline at each time point over the course of 3 months in the nine implanted eyes. All eyes developed blebs over the implant, and fluorescein testing demonstrated fluid patency at 22 days post-implantation. Slit lamp and clinical observations showed that VisiPlate was well tolerated, with low levels of conjunctival congestion, conjunctival swelling, aqueous flare, hyphema, and iris involvement from surgery that resolved over time. At sacrifice time points of 93 days and 180 days, the only notable observations were mild levels of conjunctival congestion in implanted eyes. Histopathology showed minimal tissue response and no obvious inflammation, fibrosis, or necrosis around the implant. Conclusions The results of this in vivo study demonstrate the biocompatibility and IOP-lowering effect of a multichannel, ultrathin subconjunctival shunt in a rabbit model. The data suggest that VisiPlate may safely enhance aqueous outflow and significantly reduce intraocular pressure.