Abstract
Purpose: :
The objective of this study was to evaluate the host response over time after suprachoroidal microstent device implantation in rabbit eyes.
Methods: :
The CyPass microstent is a polyimide tubular device. The microstent is implanted ab-interno through a one-millimeter small corneal paracentesis for internal aqueous drainage into the suprachoroidal space. Thirty rabbit eyes were equally divided into three groups of 10 eyes for histology evaluation at day 30, 90 and 180, respectively, post-implantation in a GLP study.
Results: :
Histologic evaluation for inflammation was performed in all 30 eyes at the pre-specified time points. At 30 days post-implantation, the device was well tolerated with absence of inflammatory reaction in all of the 10 eyes. At day 90 and day 180 post surgery, respectively, there was no adverse reaction of host tissues and no inflammatory response in any of the 10 at each respective time point with the exception of a single multi-nucleated cell in only one specimen at 180 days. At all time points, the device-host tissue interface was clear of any inflammatory cells and/or fibrosis. Furthermore, there was no change in the architecture of the surrounding interstitial tissue.
Conclusions: :
The suprachoroidal microstent device (CyPass) was well tolerated and biocompatible in the rabbit model with essentially no inflammatory tissue response over 6 months post implantation.
Keywords: intraocular pressure • outflow: ciliary muscle