A Lorentz-force actuated needle-free intraocular injection device

Abstract

Intravitreal injection is a common treatment in ophthalmology, but it can lead to considerable patient anxiety and numerous complications. Lorentz-force actuated needle-free jet injection has been shown to successfully deliver fluid to various layers of skin, and, by its nature, may reduce intravitreal injection anxiety and complications. The challenges of adapting current Lorentz-force actuated needle-free jet injection technology to intravitreal injection were investigated using a previously developed jet injection system. Two iterations of an intravitreal injection-specific control scheme were designed, implemented, and tested. Several tools were developed in tandem with the research, including intravitreal injection 3D reconstruction software, actuator-jet transfer function generation software, and bench-top eye injection staging equipment. From injection trials into ex vivo rabbit eyes, we find that needle-free jet injection can be used for intravitreal drug delivery. The new system is capable of delivering 40 [mu]L of fluid to the posterior vitreous humor, with an injection duration less than 100 ms and scleral entry site less than 350 [mu]m in diameter. A relationship has been developed between injection parameters and eye damage metrics that can be used for future parameter optimization, minimizing damage to the eye.