This Small Business Technology Transfer (STTR) Phase I project enables the development of laser-induced refractive index change (LIRIC) for non-invasive vision correction in cornea and hydrogel materials. In the United States, 150 million adults use some form of vision correction, and this number is projected to increase steadily with the aging population. LIRIC has the potential to transform how laser refractive surgery is performed and how hydrogel-based solutions (e.g., contact lenses, intraocular lenses) are produced. For use in the cornea, LIRIC is a process that can alter the optical quality of the cornea without cutting, ablating or removing tissue. Also, only a thin layer of the cornea is treated, which allows a patient to continuously adjust their optics as their prescription changes over their lifetime. This is vastly different from current laser refractive surgery techniques, which are highly invasive and do not allow for future adjustment. In hydrogel materials, traditional manufacturing techniques use diamond-turned molds to achieve desired lens shape. LIRIC can change the production paradigm by enabling just-in-time manufacturing, reducing inventory costs. Additionally, because arbitrary refractive corrections are achievable with LIRIC, patients will be able to receive prescriptions with customized corrections. This capability is unavailable using today's typical manufacturing methods.
The intellectual merit of this project resides in operating an ultrafast femtosecond laser below the damage threshold to modify the refractive index of corneal or hydrogel material. By dynamically changing laser parameters (power and/or scan velocity), it is possible to create arbitrary refractive-index profiles in cornea or hydrogel, enabling the optical correction of myopia, hyperopia, astigmatism, presbyopia and higher order aberrations. Research objectives for this proposal are centered around the optimization of the LIRIC process. By investigating the impact of laser parameters and optical design of the laser delivery system, it will be possible to enhance the efficacy and safety of in-vivo LIRIC. In addition, visual performance will also be assessed in eyes wearing LIRIC contact lenses. By correcting the eye's wavefront aberrations, LIRIC optical devices are expected to significantly improve visual quality in patients beyond the capacity of currently available techniques.
