Physical model for absorption of intraocular gas.

PURPOSE To present a physical model for intraocular absorption of an inert gas used as a tamponade. METHODS The absorption kinetics of gas in contact with the retinal surface is examined, including the changing geometry of the shrinking gas bubble inside the eye. RESULTS An analytic solution is derived that predicts how the bubble dimensions change with time, yielding a formula for the lifetime of the gas bubble. Comparison to an experimental measurement shows that the analytic solution accurately replicates the time evolution of the bubble geometry. The result is also compared to an alternative exponential model, which does not predict a finite bubble lifetime. CONCLUSIONS Further experiments are needed to discriminate between the surface absorption and exponential models.