Theoretical basis of the measurement of choroidal blood flow using a radioactive inert gas clearance technique

A mathematical model for the diffusion of krypton in ocular tissues and its removal by blood flow has been developed to explain the complex clearance pattern found experimentally in the rabbit--an animal which has predominantly a choroidal circulation. Comparison of theoretical and experimental results has shown that the initial slope of the clearance curve is a measure of choroidal blood flow for values of blood flow over 500 ml/100 g/min. The shape of the curve at later times has been shown to be attributable predominantly to the diffusion of krypton into other ocular tissues.