Abstract
Purpose :
In treatment of blindness causing retinal dystrophies i.e., Retinitis pigmentosa (RP) retinal implants showed promising results. In recent years, larger devices restoring a greater field of vision were introduced. With larger size, implantation became more difficult. In this study, a novel implantation device was developed, fabricated, and tested in ex-vivo implantation surgeries. The goal was to demonstrate a reproducible, safe and in comparison, superior implantation method.
Methods :
For designing, modelling and fabrication, computer-based software was used. Anatomical dimensions of rabbit, pig and human eyes were collected from anatomical and histological data sources. The implantation devices were 3D-printed. Implantation surgery was performed on cadaveric porcine eyes. The implantation instrument was tested using a large area epiretinal stimulator, developed by this group. A standardized ophthalmologic surgical procedure was established. Intraocular pressure at various points of surgery was measured.
Results :
The implantation instrument for porcine eyes was fabricated with a length of 9.0 mm and adapted to the curvature of normal sighted human eyes with a diameter of 24.0 mm. The elliptical shaped aperture consists of 7.0 mm in length and 1.0 mm in width at its widest points. Apertures for scleral fixation were added. Further, a sealing plug closing the central aperture was introduced. During ex-vivo experiments, 3D-printed large-array port system (3D-PLAPS) improved ocular stability, sealed the incision and withstand elevated intraocular pressure during surgery. It was suitable for foldable retinal stimulators up to 14.0 mm and up to 7.0 mm in non-foldable state.
Conclusions :
The new implantation device showed practicability in implantation of large epiretinal stimulators. The newly established implantation needs to be tested in further in-vivo experiments.
The project is funded by the German Research Foundation Research Training Group 2610/1.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.