# Project Details

### Description

Our role in this project is largely confined to modeling oxygen gradients in the vitreous cavity from a source of oxygen introduced into the eye. There is currently no comprehensive model of oxygen diffusion in the eye when the source is in the vitreous cavity. Modeling of oxygen diffusion from a vitreal source is important in the present project for several reasons. First, the model parameters can be varied to predict the effectiveness of oxygen generation, reducing the number of animal experiments required. Second, results from the model can be used to help optimize the design of the generator, as well as its operating parameters. Third, the model can allow adjustment of the parameters so that results from animals can rapidly be translated to the human eye. The model can provide a complete map in space and time of the distribution of oxygen in the vitreous cavity, whereas measurements can only be made in a small number of locations. The questions to be addressed with modeling include the following: What fraction of the oxygen generated reaches the retina? What production rate and what PO2 are required at the generator? How does the supply to the retina depend on the placement of electrodes? What is the time between turning the generator and obtaining an adequate PO2 at the retina? Does the generator need to be on continuously, or can it be intermittent?

The mathematical model describing oxygen transport in the post-vitrectomized vitreous cavity will be set up in the software program COMSOL Multiphysics (also known as FEMLAB). Dr. Linsenmeierâ€™s lab has experience using this software to predict diffusion in other conditions where analytical solutions cannot be obtained. Because we were not involved in the first year of the project, we expect that the rest of the team has obtained data that we can compare to mathematical models of diffusion in years two and three. If there is not sufficient data yet, there is still work to be done in year 2 in setting up the appropriate model(s) in FEMLAB. The modeling will involve both steady and unsteady state cases. A principal outcome from the model will be the ability to determine the match between the oxygen required by the retina and the amount that the generator can provide under different conditions. The unsteady state solution will be used to estimate the times required for diffusion when the generator is turned on and off.

I will also provide consultation on oxygen measurements and assistance in measuring oxygen in the eye if requested to do so. I will direct the modeling and analysis, and will employ either a graduate student part time, or a research technician part time in order to accomplish this work.

The mathematical model describing oxygen transport in the post-vitrectomized vitreous cavity will be set up in the software program COMSOL Multiphysics (also known as FEMLAB). Dr. Linsenmeierâ€™s lab has experience using this software to predict diffusion in other conditions where analytical solutions cannot be obtained. Because we were not involved in the first year of the project, we expect that the rest of the team has obtained data that we can compare to mathematical models of diffusion in years two and three. If there is not sufficient data yet, there is still work to be done in year 2 in setting up the appropriate model(s) in FEMLAB. The modeling will involve both steady and unsteady state cases. A principal outcome from the model will be the ability to determine the match between the oxygen required by the retina and the amount that the generator can provide under different conditions. The unsteady state solution will be used to estimate the times required for diffusion when the generator is turned on and off.

I will also provide consultation on oxygen measurements and assistance in measuring oxygen in the eye if requested to do so. I will direct the modeling and analysis, and will employ either a graduate student part time, or a research technician part time in order to accomplish this work.

Status | Finished |
---|---|

Effective start/end date | 9/30/15 â†’ 6/30/16 |

### Funding

- University of Southern California (69129923//5R01EY022059-03)
- Kennedy Institute - National Eye Clinic (69129923//5R01EY022059-03)