Monte Carlo modelling of the spectral reflectance of the human eye

• Published in: Physics in medicine & biology Vol. 47; no. 16; pp. 2863 - 2877
• Main Authors: Preece, S J, Claridge, E
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 21.08.2002; Institute of Physics
• Subjects: Algorithms; Biological and medical sciences; Choroid - physiology; Choroid - radiation effects; Computer Simulation; Eye - radiation effects; Fundus Oculi; Hemoglobins - analysis; Humans; Light; Medical sciences; Melanins - analysis; Models, Biological; Monte Carlo Method; Ocular Physiological Phenomena - radiation effects; Ophthalmoscopy - methods; Pigment Epithelium of Eye - physiology; Pigment Epithelium of Eye - radiation effects; Reproducibility of Results; Retinal Pigments - analysis; Scattering, Radiation; Sensitivity and Specificity; Spectrophotometry - methods
• ISSN: 0031-9155; 1361-6560
• DOI: 10.1088/0031-9155/47/16/303

The interpretation of in vivo spectral reflectance measurements of the ocular fundus requires an accurate model of radiation transport within the eye. As well as considering the scattering and absorption processes, it is also necessary to account for appropriate histological variation. This variation results in experimentally measured spectra which vary, both with position in the eye, and between individuals. In this paper the results of a Monte Carlo simulation are presented. Three histological variables are considered: the RPE melanin concentration, the choriodal haemoglobin concentration and the choroidal melanin concentration. By considering these three variables, it is possible to generate model spectra which agree well with in vivo experimental measurements of the nasal fundus. The model has implications for the problem of extracting histological parameters from spectral reflectance measurements. These implications are discussed and a novel approach to interpretation of images of the ocular fundus suggested.