[Determination of glucose diffusion coefficient in the human eye sclera]

The diffusion coefficients of aqueous glucose solutions in human sclera in vitro were estimated. The method is based on measurements of time-dependence of collimated transmittance of scleral samples under the action of biocompatible immersion liquids. It was shown that changes in collimated transmittance are connected with the matching between the indices of refraction of scleral scatterers and interstitial fluid. The dynamics of interstitial fluid replacement was registered by recording successively the collimated transmittance spectra in the range of 400-800 nm. For a quantitative description of the replacement process, a diffusion model was proposed, which assumes that the diffusion coefficient is constant throughout the volume of the scleral sample. Experimental results for glucose solutions of concentrations 0.18, 0.3, and 0.4 g/ml are presented. The diffusion coefficients were estimated by approximating the experimental data in the framework of the proposed model.