[1] Univ Alabama Birmingham, Sch Med, Dept Neurol, Birmingham, AL 35294 USA
[2] Univ Alabama Birmingham, Sch Med, Dept Ophthalmol, Birmingham, AL 35294 USA
[3] Univ Alabama Birmingham, Sch Med, Dept Surg,Div Gen Surg, Sect Trauma Burns & Surg Crit Care, Birmingham, AL 35294 USA
[4] Univ Alabama Birmingham, Sch Publ Hlth, Dept Epidemiol & Int Hlth, Birmingham, AL 35294 USA