Title : A novel resistance sensing mechanical suprachoroidal injector: development and potential applications
Abstract:
We invented a novel resistance sensing mechanical principle which enables precise injection of flowable material into the superachoroidal space. Based on this principle, after three generations of iterative enhancements, the latest device has been optimized to administer with ease a liquid or viscoelastic substances into the suprachoroidal space of rabbit, porcine and donated human cadaver eyes. Building on this, we further propose a novel procedure of viscoelastic sheath protected suprachoroidal cannulation and subretinal injection. We can use the device to inject a viscoelastic material into the suprachoroidal space to facilitate dissection of the choroid from the sclera, further expanding the suprachoroidal space. Subsequently, a flexible cannula is introduced into this expanded space and carefully navigated toward the posterior segment of the eye. Using a microneedle housed within the cannula, targeted delivery of a therapeutic composition into the subretinal space could be achieved with precision, avoiding retinal penetration or vitreous removal. We have also developed a novel ab-externo suprachoroidal aqueous humor drainage MIGS implant. This implant, protected by the viscoelastic material, can be positioned into the supra-cilliary space with its anterior end located at the anterior chamber angle, forming a drainage canal between the anterior chamber and the superachoroidal space. In a rabbit model of steroid-induced glaucoma, our device demonstrated a promising effect on lowering intraocular pressure, along with an excellent safety profile. A subsequent design was developed to enhance the stability of this MIGS implant. Additionally, the use of our novel superachoroidal injector for suprachoroidal viscopexy in cases of acute rhegmatogenous retinal detachment represents a potential future application.
