The incidence of ocular trauma due to blast forces has increased dramatically with the introduction of new explosives technology into modern warfare.
The availability of these volatile materials, coupled with the tactics of contemporary terrorism, has caused a rise in the number of homemade bombs capable of extreme physical harm.
The United States Department of Defense classifies IEDs as explosive machines that are constructed exclusively (i.e., without mass production) and result in the direct physical harm of surrounding individuals.
The use of these bombs by insurgents has been the number one cause of death and injury among Coalition soldiers since the start of Operation Iraqi Freedom in April 2003.
[2][3] Further classification of IEDs falls under the mechanism of delivery – vehicle-based, boat-borne, animal-borne, suicide bomber – and the resultant effect upon detonation: The discharge of a bomb is characterized by the near-instantaneous sublimation of solids or rapid vaporization of liquids into the gas phase.
Despite their frequency on the warfront, the home-produced nature of these mines makes classifying patient presentations difficult for military healthcare providers.
[1][2][3] Additionally, researchers have implicated both the auditory canals and the orbitals as potential routes for wave propagation into the central nervous system[5][7][8] Ocular trauma is the fourth most common injury sustained in military combat today.
As a result, physicians have devised a concise algorithm for the treatment of patients with ocular injuries secondary to blast trauma.
Primary blast ocular trauma therefore comprises non-penetrating mechanical injuries such as hyphemas, ruptured globes, conjunctival hemorrhage, serous retinitis, and orbital fracture.
In contact with a blast wave, the skull becomes elastic due to its deformable foundation – the external environment, the cerebrospinal fluid of the dura, and the brain itself.
[2][3] If a clinically significant increase in intraocular pressure is detected with orbital compartment syndrome, the ophthalmologist may perform an emergency canthotomy on the lateral canthus.
[2][3] Suturing the laceration after the removal of foreign bodies depends on the location of global fissure: 10-0 nylon with cyanoacrylate glue is commonly used on the cornea, and processed human pericardium may be employed if it is surgically available.
Patients with closed globe injuries require observation and follow-up examination with an optometrist, including slit lamp microscope and dilated fundus inspection.
All patients that have sustained a traumatic brain injury in the absence of ocular trauma are still recommended to obtain examination by an optometrist.
[2] In the event that a victim of globe penetrating trauma cannot perceive any light within two weeks of surgical intervention, the ophthalmologist may choose to enucleate as a preventative measure against sympathetic ophthalmia.
However, this procedure is extremely rare, and current reports indicate that only one soldier in OIF has undergone enucleation in a tertiary care facility to prevent sympathetic ophthalmia.
These forms of eye protection are available in non-prescription and prescription lenses, and their use has been made mandatory at all times when soldiers are in areas of potential conflict.
[8] Despite the success of goggles and lenses against ballistic and secondary trauma, BLPS, SPECS, and SWDG forms of eye armor do not protect against primary-blast injuries.
Moss et al. (2009) used model human heads outfitted with helmets approved for use in OEF and OIF and subjected them to blast waves at 194G for 2.1 milliseconds.