1. Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham B15 2TH, UK
2. Warfighter Eye Center, Malcolm Grow Medical Clinics and Surgery Center, Joint Base Andrews, MD 20762, USA
3. Department of Neurosurgery, 88th SGC/SGCO, Wright-Patterson Air Force Base, Dayton, OH 45433, USA
4. Department of Otolaryngology, 96th Medical Group, Eglin AFB, FL 32542, USA