An age-dependent series of eye models for radiation dosimetry.

Several studies have been appeared, up to now, that indicate the effect of accurate simulation on dose received by different substructures of the eye, irradiated by external beams of short-range radiation such as electron. Different representations of the eye have consequently been introduced. Their accuracies depend on the purpose for which models are described or the degree of accuracy of information that models are based upon. All of developed models have presented the eye of an adult human, while the size, shape, and thickness of the eye substructures change with age. This work offers a series of age-dependent eye models including five models of different ages to investigate the influence of the individual age on doses to eye substructures. The absorbed dose conversion coefficients were calculated using Monte Carlo MCNP code for 17 monoenergetic broad electron beams in the range of 100 keV to 10 MeV and for 0°, 30° and 45° angles of incidence. Results showed the strong dependency of sclera and iris doses to the age (PDD above 105), for low-energies electrons. Increasing the electron energy, the PDD decreases severely for these substructure which means dose fluctuation in the age-dependent eye models reduces. For higher energies, dose fluctuations due to age become small and for some substructures could be negligible. Highlights - A series of age-dependent eye models was developed based on the realistic anatomy. - Dose conversion coefficients of eye substructures were calculated for each models. - 17 monoenergetic electron beams and three angles of incidence were considered. - Fluctuations of doses to eye sections due to the age were obtained.