SBIR-STTR Award

Presbyopia is a progressive, age-related loss of accommodation characterized by the loss of the ability of the natural crystalline lens to change its shape to enable focusing at varying distances. Conventional treatment has been limited to reading glasses, bifocals or contact lenses. Along with presbyopia, many of these patients also require spherical and astigmatic correction and in many cases develop cataracts requiring the implantation of an intraocular lens. The ideal solution for presbyopia would not only restore accommodative function but would also provide for precise, accurate and permanent correction of spherical and cylindrical refractive errors to enable the patient to be spectacle-free. Calhoun Vision proposes to develop an injectable silicone intraocular lens incorporating our proprietary light adjustable lens (LAL) material technology to provide for the restoration of accommodative power and the in-situ spherical and astigmatic refraction correction post-implantation to provide the patient with true spectacle independence for both near and distance vision. The primary objective of Phase I is to develop candidate silicone gel material formulations incorporating Calhoun Vision's proprietary light adjustable photopolymerization system for further development in Phase II. The following seven specific aims are proposed to meet the Phase I objective: (1) Develop a candidate UV absorbing silicone gel matrix material, (2) Develop LAL photopolymerization system(s) and incorporate into a silicone gel matrix, (3) Optimize the test formulations for viscosity, work time and cure time, (4) Optimize the test formulation for modulus (elasticity) in the cured lens and after photopolymerization, (5) Characterize the test formulation for optical clarity and refractive index, (6) Evaluate the photoreactivity of the macromer in cured test formulations, (7) Evaluate the material handling properties and cured lens formed in cadaver eyes for the test formulation(s) and (8) Select the candidate material for Phase II development based upon the test data generated above.

Thesaurus Terms:
biomaterial development /preparation, lens disorder, organosilicon compound, vision aid cataract, eye refraction disorder, implant, myopia, polymerization chromatography, human tissue, postmortem

Using proprietary light adjustable materials technology, Calhoun Vision's mission is to perfect vision in patients undergoing cataract and refractive surgery. The injectable, accommodating light adjustable intraocular lens system proposed to address presbyopia in the cataract patient is comprised of an injectable, gel-filled capsular lens with an adjustable, anterior capsule supported intraocular lens (AC-LAL). The ACLAL is formulated from Calhoun Vision's proprietary light adjustable silicone material which allows for in situ post-operative refractive correction of pre-existing and induced spherical and astigmatic errors. The capsular gel lens with modulus mimicking the young human lens promotes restoration of natural accommodative ability for cataract patients. The primary goal of this Phase II proposal is to demonstrate the in vivo performance of the proposed adjustable, injectable intraocular lens system in a primate model. This will be accomplished by: (1) Optimization of UV-absorbing gel material from Phase I for mechanical and optical properties, (2) Develop the AC-LAL design based upon proprietary light adjustable materials, (3) Demonstrate the safety of the ACLAL and gel material through biocompatibility studies, (4) Develop prototype packaging for sterile gel delivery into the eye, (5) Conduct in vitro testing to demonstrate accommodative amplitude, (6) Conduct rabbit studies to evaluate posterior capsule opacification with the proposed lens system, and (7) Demonstrate accommodation amplitude of the optimized adjustable, injectable lens system in a primate model. Presbyopia is a progressive, age-related loss of accommodation affecting 100 percent of the population which is characterized by the noticeable loss of near vision at the age of 40-45 years with complete loss of accommodation by the age of 50. Conventional treatment has been limited to reading glasses, bifocals or contact lenses. Calhoun Vision's proposed adjustable, injectable silicone intraocular lens incorporating our proprietary light adjustable lens (LAL) material technology may provide for the restoration of accommodative power with in situ post-implantation refraction correction to provide the patient with true spectacle independence for both near and distance vision