Causes of combat ocular trauma-related blindness from Operation Iraqi Freedom and Enduring Freedom

Abstract

BACKGROUND 

The incidence of eye injuries in military service members is high in the combat setting. This is the first study that identifies the primary reason for poor visual acuity (worse than 20/200).

METHODS 

This is a retrospective, noncomparative, interventional case series analyzing US Operation Iraqi and Enduring Freedom members who were evacuated from the theater of operations to Walter Reed Army Medical Center from 2001 through 2011. Primary outcome measures were the length of follow-up, globe survival, and anatomic causes of blindness. Secondary outcome measures included surgical procedures performed, use of eye protection, nonocular injuries, incidence of traumatic brain injury, source of injury, visual outcomes, and predictability of Ocular Trauma Score (OTS) on visual outcome. Univariate analysis was performed using χ² and Fisher’s exact test. A p < 0.01 was considered significant because of the multiple hypotheses tested.

RESULTS 

There were 265 eyes of 239 patients who had final best-corrected visual acuity of worse than 20/200. The average age was 27.4 years (range, 19–53 years). Of the patients, 97.5% were male, and 28.9% had documented use of eye protection. The average follow-up was 350.19 days (range, 3–2,421 days). There were 128 right-eye and 133 left-eye injuries, with a total of 26 bilateral injuries. There were 206 open-globe and 56 closed-globe injuries, which were further subdivided into zones. Open-globe Zone III injuries (81.6%) were the number one cause of blindness, and most injuries were caused by improvised explosive devices (64.2%). Enucleation was the most common surgery performed (40.6%) and therefore the leading cause of blindness, followed by a multifactorial cause and direct traumatic optic neuropathy.

CONCLUSION 

Ocular trauma is common among combat injuries. Close to a third of service members that experience an ocular trauma become legally blind. Further research is needed to focus on strategies to prevent injury and improve visual outcomes.

LEVEL OF EVIDENCE 

Prognostic/epidemiologic study, level V.