[1] Univ Iowa, Coll Med, Dept Ophthalmol, Vet Adm Hosp, Iowa City, IA 52242 USA
[2] Univ Iowa, Coll Med, Dept Neurol, Vet Adm Hosp, Iowa City, IA 52242 USA
[3] Univ Iowa, Coll Publ Hlth, Dept Biostat, Iowa City, IA USA
[4] Univ Melbourne, Sch Comp & Informat Syst, Melbourne, Vic, Australia
[5] Deakin Univ, Sch Med Optometry, Geelong, Vic, Australia
[6] Computat Optometry, Granada, Spain