Aging changes of dose conversion coefficients for proton exposure to the eye

Highlights: • Incorporation of age-dependent eye models into appropriate voxel phantoms. • Considering broad proton beams with energies between 10 MeV to 8 GeV as the source. • Calculation eye substructures dose conversion coefficients for three incident angles. • Studying aging changes of dose conversion for different eye substructures. In this work, the effects of aging changes of ocular substructure on proton dose conversion coefficients have been investigated. To this end, age-dependent eye models were incorporated into appropriate voxel phantoms. A broad parallel proton beam within the range of 10 MeV to 8 GeV and three incidence angles of 0, 30, and ${45}^{°}$ was considered as a source. Results show that for low energy protons, dose conversions are strongly dependent on the age and so aging changes of ocular substructure may cause discrepancies up to 60%, 120%, and 100% in dose conversion coefficients at incidence angles of 0, 30 and ${45}^{°}$, respectively. Also, it was found from the results that for proton energies above 60 MeV, proton fluence to dose conversion coefficients of eye substructures are independent of the age.