Light propagation in simulated tissue models was analysed by Monte Carlo method. For this purpose three tissue models were considered. Heart tissue without abnormality was considered as control. For other two models small spherical size tissues of different optical parameters inside the control tissue, at different depths, were introduced. Depending on the optical properties of the abnormalities the photon distributions within and on the surface of the tissues were altered. These results showed that the variation in the backscattered fraction of photons on the tissue surface helps in identifying and characterising the abnormality.