Optical properties of ocular tissues in the near infrared region

Near infrared characterization of optical properties of various tissue components of healthy human and bovine eyes has been performed. The indices of refraction (n) of these ocular tissues were determined using a Michelson interferometer. The total diffuse reflection (R-d) and total transmission (T-t) measurements have been taken for individual ocular tissue by using double-integrating spheres and infrared laser diodes. The Inverse Adding Doubling computational method based on the diffusion approximation and radiative transport theory is applied to the measured values of n, R-d, and T-t to calculate the optical absorption and scattering coefficients of the human and bovine ocular tissues. The scattering anisotropy value was determined by iteratively running the inverse adding doubling method program and a Monte Carlo simulation of light-tissue interaction until the minimum difference in experimental and computed values for R-d and T-t were realized. A comparison between the optical characterization of human and bovine ocular samples is also made.