Motor Vehicle Crash-associated Eye Injuries Presenting to U.S. Emergency Departments

Grayson W. Armstrong, BA; Allison J. Chen, BA; James G. Linakis, MD, PhD; Michael J. Mello, MD, MPH; Paul B. Greenberg, MD

Disclosures

Western J Emerg Med. 2014;15(6):693-700. 

In This Article

Discussion

To our knowledge, this is the first study to characterize and identify risk factors associated with ED-treated nonfatal MVC-associated eye injuries using a national ED database. This study underscores the importance of several trends that differ from previous literature on MVC-associated eye injuries: a recent decline in the incidence of ED-treated injuries, a decreased risk among the elderly, and an increased risk among males, adolescents (age 15 to 19) and African Americans.[3–5,15–16]

We found that the incidence of ED-treated MVC-associated eye injuries decreased during our study period. In contrast, McGwin and colleagues[3] cited an increasing trend in the risk of eye injuries from MVCs; however, their study did not focus specifically on ED-treated injuries, surveyed a different time period (1988–2001), and used a different injury database. The mandated inclusion of dual front-seat airbags in passenger cars during their study period resulted in higher rates of minor MVC-eye injuries (i.e. corneal abrasions) despite a simultaneous reduction in severe MVC-eye injuries.[4,5,17] Advanced frontal airbag systems, mandated in model year 2006, represented an improvement over previous airbag technologies in their ability to sense occupant size, seat position, seatbelt use, and crash severity so as to deploy airbags at an appropriate level of power.[18,19] The advanced airbags may have decreased MVC eye-injury risk in our study period.

An estimated 9,280 to 11,600 eyeball injuries occur in the U.S. as a result of MVCs annually.[3] Our annual incidence of ED-treated MVC eyeball injuries fell within this predicted range with the exception of our 2003 (7,793 injuries) and 2008 (6,769 injuries) data. Hence, our findings suggest that the majority of MVC eyeball injuries occurring in the U.S. were seen in EDs.

Males in our study were at the greatest risk of suffering an ED-treated MVC eye injury, which is contrary to another MVC eye injury study but is consistent with males being injured more often in MVCs.[3,14] The increased risk of MVC injury among males has been linked to a higher incidence of loss-of-control crashes and a greater incidence of speeding.[20] Crashes of increased severity and with larger changes in velocity have been associated with an increased risk of MVC eye injury.[5]

While both drivers and passengers of vehicles involved in MVCs may sustain eye injuries, drivers were treated in EDs at a higher rate during our study period. This trend is echoed in the existing MVC eye injury literature.[3–5,21] After accounting for the relative abundance of drivers at risk of MVCs when compared to passengers, however, the relative risk of MVC-associated eye injury was found to be the same for both drivers and passengers.[3]

Adolescents aged 15 to 19 had the highest rate of MVC-associated eye injuries presenting to EDs. Among licensed drivers, those in the 16- to 24-year-old age group were found to have the highest rate of MVC eye injury visits. Previous studies have identified both young drivers (16 to 35 years of age) and older drivers (>43 years of age and >66 years of age) as being at the greatest risk of MVC eye injury.[3,16,22] Our results may be due to the increased rate of MVC among adolescents and young adults, which has been attributed to driving inexperience in the youngest age groups, an increased likelihood of undertaking risky driving practices, and a decreased use of seat belts.[23–27]

Researchers have hypothesized that mechanical changes that occur in the aging eye predispose older patients to an increased risk of MVC-associated eye injury and to different injury diagnoses and outcomes.[16,28] However, we found that after the age of 18, the risk of presenting to an ED with a MVC eye injury decreased with increasing age. Indeed, the elderly population had the lowest rate of MVC eye injury per person among adults. The elderly also had the lowest rate of MVC eye injury across nearly all diagnostic categories. Several explanations may account for our results. First, elderly persons increasingly forego driving motor vehicles voluntarily as they age.[29–30] Second, many states require elderly persons to undergo in-person license renewal as well as visual acuity and driving testing, which allows states to limit licensing of high-risk elderly drivers.[31–33] Lastly, elderly patients have the highest rate of seat belt use, a behavior known to decrease eye injury risk.[7,34] These findings are especially important in light of the rapidly increasing population of elderly individuals in the U.S.[35]

Our study found that African Americans had the highest rate of ED-treated MVC eye injuries. Praevious studies have found that African Americans use seat belts less often than other racial and ethnic populations, a practice shown to increase the risk of MVC eye injury.[3,7,36]

Similar to previous studies, we identified corneal abrasion/contusion, foreign body and hemorrhage as the most common ED-treated ocular diagnoses resulting from MVCs, especially after the deployment of an airbag.[3–7,37–40] While the NEISS-AIP is unable to provide detailed information regarding foreign body and hemorrhage diagnoses, existing case reports and reviews document the injury variability within these broad diagnostic categories.[40–44]

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