Abstract
Purpose :
Subretinal injections are increasing important for a variety of vitreoretinal procedures but require micrometer accuracy. We developed a novel optical coherence tomography (OCT) probe with an integrated light source that continuously images a microneedle tip to perform subretinal injections.
Methods :
A 36-gauge coplanar needle attached to a 25-gauge B-scan OCT (870 nm) probe with an integrated fiberoptic cable was introduced through a 23-gauge trocar into the vitreous cavity of fresh ex-vivo porcine eyes and a model eye. A modified split-screen heads-up display (TrueVision Systems Inc., Santa Barbara, CA) with the simultaneous en face 3D surgical microscope image on the left and the real-time unprocessed continuous B-scan OCT image from the probe on the right were used to view the surgical maneuvers. Observations were recorded.
Results :
The microneedle OCT probe with integrated light source successfully tracked the needle tip through the vitreous and retinal layers in real time to the desired subretinal location. The probe fit smoothly through a 23-gauge trocar. The integrated light source on the probe adequately illuminated the retinal surface without the need of an additional instrument. The integrated light source also produced a triangular shadow from the needle tip as it approached the retinal surface which provided additional positioning information above the retina. The heads-up display permitted simultaneous real-time visualization of the microscope en face and B-scan OCT images to provide wide-field and localized inputs. No focusing or tracking computer algorithms were required to maintain the needle tip image.
Conclusions :
The novel microneedle OCT with integrated light source probe demonstrated capacity for subretinal injection delivery using just one 23 -gauge trocar; thus greatly simplifying an advanced and challenging surgical procedure.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.