| Degenerative retinal diseases such as Retinitis Pigmentosa and Age-Related Macular Degeneration are, together, one of the leading causes of blindness in the United States. Retinal prostheses bypass the degenerated cells and apply electrical stimulation directly to the visual neural pathway, creating an artificial sensation of sight in subjects with retinal blindness. Current prostheses utilize a polymer electrode array, which is affixed to the retina using a retinal tack. The electrode array applies mechanical pressure to the retina, which can cause mechanical damage to the very cells which are required to transmit the applied signal. We can mitigate or relocate mechanical damage to the retina through electrode array design changes, but to do so, we must thoroughly understand the mechanical interface between the array and the retina.;I have generated a computerized model of the mechanical interaction of array and eye wall using solid modeling and Finite Element Analysis techniques. I describe and justify the choices made in the development of this model, define model inputs, provide results from ten studies, and validate the accuracy of model results through comparison to experimental data. This work is significant in that it combines a modifiable device and a complex series of biomaterials in the same model, demonstrating that it is feasible to satisfy the sometimes conflicting goals of product design and biomaterials modeling simultaneously. This model can now be used by retinal prosthesis developers to optimize electrode array design, reduce mechanical damage to the retina, and improve device efficacy. |
