OPTICAL-PROPERTIES OF OCULAR FUNDUS TISSUES - AN IN-VITRO STUDY USINGTHE DOUBLE-INTEGRATING-SPHERE TECHNIQUE AND INVERSE MONTE-CARLO SIMULATION

Various models have been published calculating the light transport at the ocular fundus either for interpretation of in vivo reflectance mea surements or for the prediction of photocoagulation effects. All these models took the absorption spectra of the pigments located at the ocu lar fundus, melanin, haemoglobin, xanthophyll, and the photoreceptor p igments, into account. However, light scattering inside the single fun dus layers has not been investigated in detail and was, therefore, neg lected in the calculations or only considered by very rough approximat ions. This paper presents measurements on specimens of retina, retinal pigment epithelium, choroid, and sclera using the double-integrating- sphere technique. Absorption coefficients, scattering coefficients, an d anisotropy of scattering were calculated by an inverse Monte Carlo s imulation from the measured collimated and diffuse transmittance and d iffuse reflectance. Conclusions are drawn for the interpretation of fu ndus reflectance measurements, which are a useful tool in diagnostics and photocoagulation dosimetry.