Investigation of Surgical Techniques for Optimization of Long-Term Outcomes of LCP-Based Retinal Prosthesis Implantation

Transl Vis Sci Technol. 2018 Aug 24;7(4):17. doi: 10.1167/tvst.7.4.17. eCollection 2018 Aug.

Abstract

Purpose: To investigate reproducible surgical techniques to optimize the long-term safety of liquid crystal polymer (LCP)-based retinal prosthesis implantation.

Methods: An LCP-based retinal prosthesis is fabricated monolithically on a single-body LCP substrate with all components, including the package and electrode array. We implanted the electrode array into the suprachoroidal space and anchored the package and transition part to the sclera in rabbits (n = 11). The safety profile was assessed upon the completion of the surgery and postoperatively.

Results: The surgical procedures for implantation of the entire system were easily performed in nine eyes (81.8%) without any intraoperative complications. In the other two eyes (18.2%), surgical complications related to electrode insertion, including optic nerve damage and retinal tear, arose. In 10 eyes (90.9%), the devices were well tolerated for at least 3 months. However, in most eyes (nine; 81.8%), two complications began to appear after 3 months, postoperatively, including conjunctival erosion or dehiscence over the package or transition part. The electrode arrays were maintained safely in the suprachoroidal space after surgery without any complications, regardless of the status of the extraocular components in all cases except two intraoperative complications.

Conclusions: We established safe and reproducible surgical techniques for implantation of our LCP-based retinal prosthesis into the suprachoroidal space. Although issues related to surgical technique or device configuration were identified, further technical solutions would improve the long-term safety of device implantation.

Translational relevance: This study presents successful implantation of LCP-based retinal prosthesis. The technical solutions will permit an optimization of surgical techniques.

Keywords: liquid crystal polymer; retinal prosthesis; suprachoroidal; surgery.