A mathematical model to calculate temperature distributions in human and rabbit eyes during hyperthermic treatment.

A mathematical model based on the finite difference method has been developed to calculate transient and steady state temperature distributions in normal unexposed human and rabbit eyes, and human and rabbit eyes heated by various heating techniques. The normal steady state temperature distributions in human and rabbit eyes are given. The model has been experimentally fitted to data obtained from measurements on rabbit eyes. The heat transfer from the choroid to the body core temperature of the rabbit is described by the heat transfer coefficient hs = 65 W m-2 degrees C-1, and from the cornea to the surrounding air temperature by hc = 20 W m-2 degrees C-1. The thermal conductivity and the specific heat of the lens of the rabbit eye were determined empirically to be 0.40 W m-1 degree C-1 and 3.0 J g-1 degree C-1 respectively. The thermal properties of the vitreous humour were taken to be equal to the thermal properties of water.