Mathematical model of TMA+ diffusion and prediction of light-dependent subretinal hydration in chick retina (original) (raw)

Investigative Ophthalmology &amp Visual Science

Abstract

To derive a mathematical model of TMA+ diffusion across the retina that can be used to estimate the amplitude and kinetics of the light-evoked increase in subretinal hydration and its effect on the concentration of other ions. All experimental data were obtained in chick retina-pigment epithelium-choroid preparations as described in the accompanying paper. Diffusional properties of the retina were derived from the time course of [TMA+]o in the subretinal space (SRS) after changes in the retinal perfusate. Then, the SRS volume changes underlying the light-induced [TMA+]o response can be derived using a mathematical model of TMA+ diffusion. Complete retinal depth series of light-evoked [TMA+]o responses could be simulated by producing a corresponding expansion of the SRS. Volume changes inferred from the diffusion model were 2.2 to 3.8 times larger and more prolonged than could be derived directly from delta [TMA+]o. The model predicted up to a 20% peak increase in subretinal-space hy...

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