Abstract
Purpose:
With the advent of gene therapy for hereditary retinal diseases, and a growing interest in performing gene therapy on young children, techniques to perform retinal injections that avoid creating a hole in the retina are likely to be increasingly preferred. But trans-choroidal, sub-retinal injections, which avoid making a retinal hole, also require extreme precision positioning the needle. Therefore, we have attempted to reproduce this procedure using the DaVinci robot. Its motion scaling ability affords a 10:1 de-amplification of the surgeon’s range of movement, which reduces complications related to human tremor and yields increased precision.
Methods:
A Da Vinci Si(R) Surgical Robot, was utilized to perform trans-scleral sub-retinal injections in a porcine model. A Thornton fixation ring was utilized to stabilize the globe, the retina was directly visualized using only the Da Vinci camera, and ICG dye was injected in a sub-retinal fashion and directly visualized with the ICG filters on the Da Vinci system. The injection was made using a repurposed Butterfly needle, which was grasped and maneuvered by the large ridged forceps tool of the Da Vinci system. The injection itself was made by hand using a 10cc syringe attached to the tube of the Butterfly needle.
Results:
Trans-scleral, sub-retinal injection with the Da Vinci robot is possible, with appropriate modification of the instrumentation. There is a significant learning curve to be able to successfully perform such injections.
Conclusions:
Our results suggest that robotically assisted, trans-choroidal delivery of viral vectors for gene therapy may be effective in reducing the incidence of retinal detachment and other adverse outcomes. Stabilization of the eye is critical to successful sub-retinal injection. Larger (thicker than 25 gauge) needles are better able to penetrate the porcine sclera.