Simulation and analysis of light scattering by multilamellar bodies present in the human eye

Abstract

A modified computational model of the human eye was used to obtain and compare different probability density functions, radial profiles of light pattern distributions, and images of the point spread function formed in the human retina under the presence of different kinds of particles inside crystalline lenses suffering from cataracts. Specifically, this work uses simple particles without shells and multilamellar bodies (MLBs) with shells. The emergence of such particles alters the formation of images on the retina. Moreover, the MLBs change over time, which affects properties such as the refractive index of their shell. Hence, this work not only simulates the presence of such particles but also evaluates the incidence of particle parameters such as particle diameter, particle thickness, and shell refractive index, which are set based on reported experimental values. In addition, two wavelengths (400 nm and 700 nm) are used for light passing through the different layers of the computational model. The effects of these parameters on light scattering are analyzed using the simulation results. Further, in these results, the effects of light scattering on image formation can be seen when single particles, early-stage MLBs, or mature MLBs are incorporated in the model. Finally, it is found that particle diameter has the greatest impact on image formation.

Numerical model of the inhomogeneous scattering by the human lens

“…The mean size of these particles is around 2.13 microns in diameter. As it is shown by Costello et al [11] and Mendez-Aguilar et al [13], the size of these particles, together with the index jump between the vesicle shell, the inner body, and the external medium makes these vesicles highly efficient scatterers with a relatively high cross-section. In all of these works, the concentration of the vesicles within the human lens is deemed as constant for a given eye, but it can vary between eyes.…”

Improving accuracy of corneal power measurement with partial coherence interferometry after corneal refractive surgery using a multivariate polynomial approach

“…The use of mathematical methods to replicate medical phenomena has certainly broadened the area of research in the field of simulation and testing. On the other hand, it is difficult to reproduce any process occurring in the living organism using the limited tools offered by mathematics [ 30 – 32 ]. While artificial intelligence methods still have certain limitations, they should prove useful in this field of knowledge.…”

Análisis de la composición espectral del iluminante sobre distintas características del sistema visual humano en el rango mesópico

“…En el caso del cristalino con cataratas, la presencia de opacidades se traduce en un incremento en la presencia de cuerpos multilamelares (Costello et al, 2007), partículas compuestas por proteínas citoplasmáticas cubiertas por múltiples capas lipídicas, que alcanzan un tamaño de entre 1 μm y 4 μm (Méndez-Aguilar et al, 2017). Estas opacidades tienen dos consecuencias.…”