Simulation of diffusion in three unique situations for the novel capsule drug ring

This work reports the results of simulations of drug release from a capsule drug ring (CDR) and the diffusion of that drug throughout the eye. The capsule drug ring (CDR) was recently developed at the University of Utah and is designed to be implanted with an intraocular lens after a cataract surgery. The CDR contains the drug Avastin which targets the protein called VEGF to prevent it from building new blood vessels that contribute to macular degeneration. The capsule drug ring is designed to be placed in the lens capsule near the vitreous humor to allow the Avastin to travel across the vitreous humor to the retina at the back of the eye. As the design is new, and no similar devices have been tested or developed, no other attempts have been made to model this situation so there is no data/information available. Accordingly, this work reports on the modeling and simulation of the CDR drug release and the drug transport across the eye. This is the main objective of the work done in this research. Three unique situations were created using SolidWorks, and COMSOL was used to simulate Avastin transport inside the human eye. The three unique situations included an intravitreal injection of Avastin into the vitreous humor, the CDR with Avastin diffusing into the vitreous humor, and a constant drug flow of Avastin into the vitreous humor. Comparing the three situations, we found that the CDR provides approximately 13 times the amount of Avastin to the rear of the vitreous humor than a typical intravitreal injection of Avastin. Another finding was that the CDR exceeds the minimum daily dosage of Avastin to treat age-related macular degeneration for the first seven weeks, and continues to provide a substantial amount of Avastin to the rear of the vitreous humor for the full six months of simulation. The average concentration of the drug throughout the six months was estimated to be around 6 to 12 mol/m 3 of Avastin, which exceeds the estimated average concentration for intravitreal injection after six months of injections.