• Anna Ivanova

Determination of optical parameters of the porcine eye and development of a simulated model



Short summary of the article, Determination of optical parameters of the porcine eye and development of a simulated model by Regal et al.: This study evaluated the optical parameters of the cornea, lens, vitreous humor, sclera, iris, choroids and eyelid of the porcine eye for wavelengths between 400 and 1400 nm.


Recently, the number of laser surgery to correct optical aberrations has significantly increased. Improving the knowledge related to the interactions of light with the eye will enhance the efficiency of the surgery. For this reason, this study presents a complete optical characterization of the porcine eye.

There are few consistent values regarding the refractive index, the absorption and scattering coefficients in the literature. Furthermore, there are differences in the research methodologies in previous studies. For instance, researchers use different equipment, methods or animals to calculate these coefficients. Inconsistent results as well as the lack of data for some eye tissues have motivated this research.

The purpose of this study was to create an eye simulated model which eases the development of the new laser treatment by facilitating the understanding of the light propagation inside the porcine eye.

Kubelka-Munk and Inverse Adding-Doubling methods were used in spectroscopy measurement to determine the absorption and scattering coefficients. The refractive index was measured by ellipsometry. The different parameters were obtained for the cornea, lens, vitreous humor, sclera, iris, choroids and eyelid in the visible and infra-red regions. Afterwards, the results were implemented in a COMSOL Multiphysics® software to create a realistic eye model.

As expected, the refractive index decreases as the wavelength increases. These results complement those found in the literature and provide values for iris and choroids. The measurements were obtained from an average of at least three different samples for each element. The R2 of each fit was greater than 0.92.

This model gives a better understanding of the propagation of light in the eye by adding optical parts such as the iris, the sclera or the ciliary bodies. This research allows researchers to test different procedures related to light surgeries, such as being able to quantify the percentage of light absorbed for each part of the eye and see which parts are likely to have heat elevations.


Reference

Regal S, O'Connor D, Brige P, et al. Determination of Optical Parameters of the Porcine Eye and Development of a Simulated Model. J Biophotonics 2019;12:e201800398.

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