Characteristics of Open Globe Injuries in the United States From 2006 to 2014

Key Points

Question  What were the population-based characteristics of open globe injuries in the United States from 2006 to 2014 from the Nationwide Emergency Department Sample?

Findings  This cross-sectional study of 124 989 emergency department visits for open globe injuries found that the incidence of open globe injuries was 4.49 per 100 000 population, accounting for $793 million in total charges. Males and individuals with a low socioeconomic status were at increased risk, and the incidence of open globe injuries associated with falls increased during the study period.

Meanings  These results suggest preventive efforts for open globe injuries should target males, individuals at risk for falls, and those from a low socioeconomic background.

Importance  Open globe injuries can lead to substantial visual morbidity and lifelong sequelae. Interventions to reduce the burden of open globe injuries in the United States require a better understanding of these injuries through well-designed epidemiologic investigations.

Objective  To examine the incidence, common injury mechanisms, and economic burden of open globe injuries in the United States.

Design, Setting, and Participants  This retrospective, cross-sectional study of US nationwide emergency department (ED) data assessed all ED visits of patients with a primary diagnosis of open globe injury in the Nationwide Emergency Department Sample (NEDS) from January 1, 2006, to December 31, 2014. Data analysis was performed from August 29, 2018, to November 11, 2019.

Main Outcomes and Measures  Annual incidence of open globe injuries by age, sex, mechanism of injury, and concomitant diagnosis, as well as median charges associated with open globe injuries and variables associated with hospitalization.

Results  A total of 124 989 ED visits for open globe injuries were assessed, with an incidence of 4.49 per 100 000 population in the United States from 2006 to 2014 (mean [SD] age of study participants, 37.7 [22.5] years; 94 078 [75.3%] male). The incidence was highest in 2006 (5.88 per 100 000 population) and decreased by 0.3% per month between 2006 and 2014 (incidence rate ratio, 0.99; 95% CI, 0.99-0.99; P < .001). Open globe injuries occurred in 37 060 individuals (30.6%) of low socioeconomic status. The most common injury mechanism was being struck by or against an object or person (40 119 of all 124 989 injury mechanisms [32.1%]). Open globe injuries associated with falls increased 6.6% between 2006-2010 and 2011-2015 (95% CI, 1.04-1.08; P < .001) and were the most common injury mechanism in individuals older than 70 years. The total cost associated with open globe injuries was $793 million. The cost of ED visits increased from $865 during 2006-2010 to $1557 during 2011-2015. Inpatient costs similarly increased from $21 527 during 2006-2010 to $30 243 during 2011-2015.

Conclusions and Relevance  The incidence of open globe injuries in the United States decreased from 2006 to 2014. Although the data are from 5 to 13 years ago, these findings appear to provide valuable information for targeting preventive measures toward individuals at highest risk; targeting young men with lower socioeconomic status and individuals 70 years or older at an increased risk of falls may help lower the incidence of open globe injuries.

Ocular trauma remains the leading cause of monocular vision loss in the United States,¹ with one-third of serious eye injuries resulting in eventual blindness.² Globe rupture and perforation are prominent risk factors for blindness from ocular trauma.² Despite the associated visual morbidity, greater than 90% of ocular trauma cases are preventable.^3-5 Current data on open globe injuries are lacking. A few recent reports^6-8 have investigated the burden of ocular trauma in the United States; however, to our knowledge, no studies have specifically investigated the epidemiologic characteristics of open globe injuries. The severity, visual morbidity, and economic burden associated with open globe injuries make them more consequential to patients, health care systems, and society at large. Therefore, there is a need for these injuries to be studied and understood as a separate entity in the field of ocular trauma.

Quiz Ref IDThe purpose of our study was to fill this gap in knowledge by using the Nationwide Emergency Department Sample (NEDS) as a surveillance system for open globe injuries. Specifically, we investigated (1) temporal trends in the incidence of open globe injuries in the United States; (2) common injury mechanisms, associated injuries, and population at risk; (3) economic burden associated with emergency department (ED) visits and inpatient admissions; and (4) variables associated with inpatient hospitalization.

For this cross-sectional study, NEDS was queried to identify all ED visits in the United States from January 1, 2006, to December 31, 2014, with a primary diagnosis of open globe injury. This study was approved by the institutional review board of the Johns Hopkins Hospital and was conducted in adherence with the Declaration of Helsinki⁹ and US federal and state laws. Because this was a retrospective analysis of deidentified data, informed consent was not needed.

At present, NEDS is the largest all-payer ED database in the United States and is part of the Healthcare Cost and Utilization Project. It contains a 20% stratified sample of hospital-based EDs across the United States, with approximately 31 million ED visits each year from more than 950 hospitals. Analyses discussed and results presented in this study represent data that were weighted according to the NEDS sampling frame to generate national estimates. Additional information on the NEDS sampling strategy is available online.¹⁰ Data analysis was performed from August 29, 2018, to November 11, 2019.

Patients with a primary diagnosis of open globe injury and associated ocular comorbidities were identified using relevant International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes (eTable 1 and eTable 2 in the Supplement). Median charges per ED visit and inpatient hospitalization were calculated and inflation-adjusted using the Consumer Price Index for Hospital Services from the US Bureau of Labor Statistics.¹¹ The charges along with their 95% CIs were computed using an adaptation of the R svyquantile command (R Project for Statistical Computing), which uses the method of Woodruff¹² to compute a Wald-type CI.

Descriptive statistics were presented as numbers (percentages) for categorical variables and means (SEMs) for continuous variables. Annual incidence of open globe injuries was calculated using US census data; the total number of open globe visits during the study period were divided by the total US population in the same period. Univariable and multivariable logistic regression models were used to assess variables associated with inpatient hospital admissions. All P values were nominal and 2-sided, and P < .05 was considered to be statistically significant. All statistical analyses were performed using Stata/MP, version 14.2 (StataCorp).

Quiz Ref IDA total of 6.2 million ED visits for ocular trauma occurred in the United States during the 9-year study period (2006-2014), of which 124 989 were open globe injuries (mean [SD] age of study participants, 37.7 [22.5] years; 94 078 [75.3%] male), with an incidence of 4.49 per 100 000 population (Table 1). The incidence was highest in 2006 (5.88 per 100 000 population) and decreased by 0.3% per month (incidence rate ratio, 0.99; 95% CI, 0.99-0.99; P < .001) between 2006 and 2014. The incidence of open globe injuries was the lowest in 2014 (3.92 per 100 000 population) (Figure 1A). Open globe injuries occurred in 37 060 individuals (30.6%) of low socioeconomic status. A total of 44 247 patients (35.7%) had private insurance, 16 109 (13.0%) had Medicare, and 21 542 (17.4%) had Medicaid. A total of 70 068 patients (56.1%) were seen at metropolitan teaching hospitals, with 29 432 (23.5%) seen at a level I trauma center, 9338 (7.5%) at a level II trauma center, and 7689 (6.2%) at a level III trauma center. A total of 81 089 patients (64.9%) with open globe injuries were treated and discharged from the ED, whereas 25 367 patients (20.3%) were hospitalized. Seasonal variations were observed, with open globe injuries being more frequent during the summer months and least frequent in the winters.

Quiz Ref IDThe most common mechanism of injury overall was being struck by or against an object or person (40 119 [32.1%]), followed by cutting or piercing (18 828 [15.1%]), unintentional entry of foreign body to the eye and adnexa (18 227 [14.6%]), falls (11 992 [9.6%]), motor vehicle crash (3644 [2.9%]), injury by firearms (1737 [1.4%]), and injury by use of machinery (1232 [1.0%]) (Table 2). Analysis of temporal trends of injury mechanism found an increasing proportion of fall-related open globe injuries (Figure 1B). The number of fall-related open globe injuries increased 6.6% between 2006-2010 and 2011-2015 (odds ratio [OR], 1.06; 95% CI, 1.04-1.08; P < .001). Analysis of mechanism of injury was also conducted by stratifying the study population by age (eFigure in the Supplement). Cutting or piercing was a common injury mechanism in younger individuals, responsible for 4946 open globe injuries (18.7%) between the ages of 0 and 17 years. On the contrary, cutting or piercing was less common among those 70 years or older, with only 485 patients (4.2%) older than 70 years having such injuries. Motor vehicle crash–related open globe injuries were most common during the second and third decades of life. Falls were responsible for 53.1% of open globe injuries in individuals 70 years or older. Although women were more likely to experience open globe injuries secondary to falls (6279 [20.4%] of 30 850 vs 5714 [6.1%] of 94 075, P < .001), injuries related to machinery (1211 [1.3%] of 94 075 vs 21 [0.1%] of 30 850, P < .001) and foreign body (15 975 [17%] of 94 075 vs 2231 [7.2%] of 30 850, P < .001) entering the eye were more common in men.

In this cohort of patients, facial or orbital fractures were the most common concomitant ocular diagnosis associated with open globe injuries (6927 [5.5%]), followed by eyelid laceration (5547 [4.4%]). Common anterior segment injuries included traumatic cataract (3139 [2.5%]) and hyphema (1064 [0.9%]), whereas posterior segment injuries included vitreous hemorrhage (2719 [2.2%]), retinal hemorrhage (255 [0.2%]), retinal detachment (1465 [1.2%]), choroidal detachment (214 [0.4%]), and endophthalmitis (582 [0.5%]) (Figure 2A). Analysis for concomitant diagnosis was also conducted by stratifying the study population by age (Table 2 and Figure 2B). The percentage of individuals with concomitant facial or orbital fractures increased with older age, with 11.8% of individuals 70 years or older experiencing facial or orbital fractures compared with 1.3% of individuals aged 0 to 17 years. Concomitant diagnosis of hyphema and vitreous hemorrhage also increased with age, whereas traumatic cataract decreased with increasing patient age. A total of 1845 of 124 989 patients (1.5%) eventually needed enucleation. The rate of enucleation was higher among patients 70 years or older.

Univariable analysis found that older age was significantly associated with inpatient hospital admission, with the highest odds of hospitalization among patients 70 years or older (OR, 3.42 vs individuals <18 years of age; 95% CI, 2.87-4.07; P < .001). Patients were more likely to be admitted if they presented to a metropolitan teaching hospital (OR, 3.63; 95% CI, 2.77-4.77; P < .001) and if the hospital was a level I (OR, 5.41; 95% CI, 2.65-11.08; P < .001) or level II (OR, 2.98; 95% CI, 1.44-6.13; P = .003) trauma center. Mechanism of injury was associated with the odds of hospitalization, with patients with injuries secondary to firearms (OR, 5.62; 95% CI, 4.24-7.46; P < .001), falls (OR, 3.00; 95% CI, 2.65-3.41; P < .001), motor vehicle crash (OR, 2.91; 95% CI, 2.34-3.63; P < .001), and machinery use (OR, 1.77; 95% CI, 1.34-2.32; P < .001) being more likely to be hospitalized than those presenting with other injury mechanisms. Concomitant ocular diagnosis was also associated with increased odds of hospitalization. Odds were greatest among patients with facial or orbital fractures (OR, 8.50; 95% CI, 6.97-10.37; P < .001), endophthalmitis (OR, 7.18; 95% CI, 4.43-11.64; P < .001), choroidal hemorrhage (OR, 5.88; 95% CI, 3.69-9.38; P < .001), retrobulbar hemorrhage (OR, 5.66; 95% CI, 2.02-15.86; P = .001), and choroidal detachment (OR, 5.63; 95% CI, 2.16-14.72; P < .001) (Table 3 and eTable 3 in the Supplement).

Multivariable analysis found similar results, with individuals 70 years or older twice as likely to be hospitalized (OR, 1.99; 95% CI, 1.56-2.54; P < .001). Teaching hospital status (OR, 2.2; 95% CI, 1.26-3.96; P = .006) and level I trauma center designation (OR, 2.48; 95% CI, 1.02-6.06; P = .04) were also associated with increased odds of hospitalization; hospitals in the Midwest (OR, 0.40; 95% CI, 0.23-0.67; P < .001) and the South (OR, 0.46; 95% CI, 0.25-0.86; P = .02) had lower rates of hospitalization than those in the Northeast. Hospitalization rates were lower among Medicaid patients (OR, 0.54; 95% CI, 0.47-0.62; P < .001) and those who were privately insured (OR, 0.33; 95% CI, 0.27-0.39; P < .001) compared with Medicare patients. Firearm (OR, 3.62; 95% CI, 2.64-4.96; P < .001) and motor vehicle crash–related injuries (OR, 2.49; 95% CI, 1.98-3.13; P < .001) had the greatest odds of hospitalization. The presence of 1 concomitant diagnosis was associated with increased odds of hospitalization by 4.3 times (OR, 4.27; 95% CI, 3.75-4.87; P < .001), whereas having 2 or more concomitant diagnoses was associated with increased odds by 7.3 times (OR, 7.30; 95% CI, 5.25-10.17; P < .001).

The total costs associated with ED visits and hospital admissions of patients with ocular trauma was $9.5 billion, and although open globe injuries comprised only 2.0% of ocular trauma cases, they were responsible for 8.3% ($793 million) of the total ocular trauma charges. The total ED cost associated with open globe injuries was $241 million, and the total inpatient admission cost was $552 million. The median cost per ED visit was $1120 (95% CI, $980-$1282). When stratified according to age, the median ED cost per visit was highest ($1998; 95% CI, $1726-$2432) for patients 70 years or older. Compared with 2006-2010 ($865; 95% CI, $750-$1010), the median ED cost per visit approximately doubled during 2011-2015 ($1557; 95% CI, $1404-$1762). Charges were highest for metropolitan teaching hospitals ($1404; 95% CI, $1102-$1852) and hospitals that were designated trauma centers ($1748; 95% CI, $1553-$2024). The median inpatient charges for patients admitted from the ED were $24 503 (95% CI, $21 357-$28 450), with the charges highest for patients 70 years or older ($29 382; 95% CI, $24 970-$30 386). The inpatient charges increased from $21 257 (95% CI, $18 252-$25 518) during 2006-2010 to $30 243 (95% CI, $25 814-$36 207) during 2011-2015 and were highest for metropolitan nonteaching hospitals ($27 506; 95% CI, $24 970-$30 386) and trauma centers ($27 932; 95% CI, $25 292-$30 915). The ED and inpatient admission charges associated with open globe injures are summarized in eTable 4 in the Supplement.

Open globe injuries comprise 2.0% of ocular trauma cases in the United States but are responsible for 8.3% of costs for ocular trauma treatment. These findings are consistent with findings from other developed countries.¹³ Open globe injuries also substantially increase the burden of hospitalizations for ocular trauma. The reported inpatient admission rate among patients with ocular injuries is 1.4%.¹⁴ This burden is several folds higher in patients with open globe injuries; 20.3% of patients in our study were hospitalized after being evaluated in the ED. Although the direct costs associated with treatment, surgical intervention, and need for hospitalization remain high, the ensuing visual morbidity results in additional costs in the form of lost workdays, disability, reduced quality of life, and psychological outcomes.

Although the incidence of open globe injuries in the United States is decreasing, it remains higher than that reported by other developed countries,^15-17 highlighting the potential to lower the rate even further. Similar to other eye injuries,^14,18 open globe injuries most commonly affect young individuals, especially males. Younger men are more likely to work in environments that are more hazardous, and interpersonal injuries are also more common in this group.¹⁹ Poorer individuals also have more open globe injuries. This finding is particularly concerning because these individuals may lack the resources to seek timely medical care and may be less well equipped to deal with the ensuing visual morbidity and disability. Similar economic disparities in the rates of hospitalizations for ocular trauma have been previously reported.⁷

Although most mechanisms of injury decreased or were stable over the years, fall-related open globe injuries continued to increase in the United States. Previous studies^20,21 have identified falls as a frequent cause of open globe injuries in elderly individuals. In 2006, falls were responsible for 7.5% of open globe injuries compared with 10.9% in 2014, which represents a 45% increase during a 9-year study period. Falls alone were responsible for greater than 50% of open globe injuries in individuals 70 years or older and were associated with more than 3-fold increased odds of hospitalization. Similar patterns have been observed in other developed countries; in Australia, falls were responsible for 43% of open globe injuries, with most fall-related injuries occurring in elderly individuals (mean age, 73 years).²² These injuries also occurred more commonly in women, which is in line with a prior report.¹⁸ A previous study¹⁸ found particularly poor visual outcomes in eyes with fall-related open globe injuries, with eventual blindness in two-thirds of eyes. As the US population continues to age, ophthalmologists should be well prepared to handle an increasing number of fall-related eye injuries in the future. Because individuals with visual impairments may be particularly prone to falls, ophthalmology clinics can play a unique role in the risk assessment of individuals 65 years or older for falls and in providing education and counseling on fall prevention measures and appropriate referral to fall prevention programs. Prior intraocular surgery has been associated with fall-related open globe injuries.^22,23 A patient undergoing intraocular surgery with concomitant risk factors, such as increased risk of falls, should be appropriately counseled by ophthalmologists to prevent future risk of open globe injuries.

Firearm-related open globe injuries are associated with a poor visual outcome²⁴ and frequent hospitalizations, likely in part because of multiple injuries. In our study, the odds of hospitalization were 6 times greater in individuals with firearm-related open globe injury. Motor vehicle crashes have previously been reported as the most frequent injury mechanism for hospital-based ocular emergencies.^18,25 In this study, they were responsible for only 2.9% of open globe injuries and decreased as a cause of open globes during the study period. This finding is in line with data published using the National Electronic Injury Surveillance System All Injury Program, which reported a decrease in the rate of motor vehicle crash–associated eye injuries in the United States.²⁶ Enhanced seat belt enforcement campaigns and universal air bag requirements, as well as improvements in air bag technology, can partly explain this decrease.^1,10,11,27 Most open globe injuries occurred during the summer months; similar seasonal trends have been observed by prior studies,^6,28,29 and this finding can partly be explained by an increase in outdoor activities (recreational and labor) during the summer months.

The presence of orbital fractures is associated with a worse visual outcome in patients with open globe injuries, likely indicating a more severe injury to the globe.³⁰ Orbital fractures have been previously reported as the most common primary diagnosis among hospitalized patients with ocular trauma.⁷ Approximately 12% of patients older than 70 years had associated facial or orbital fracture, and these patients were 8.5 times more likely to be hospitalized.

The strengths of this study include its large, nationally representative sample size and completeness of data because the NEDS is a validated database and reporting is required. Limitations of our study include the study cohort having been identified using ICD-9-CM codes. Thus, it is possible that some diagnoses were inaccurately coded or that factors other than ocular trauma led to hospitalizations. In addition, the NEDS registry does not include information on some important clinical factors, such as visual acuity and severity of injury, and limitations exist in the classification of injury mechanisms. The absence of a national ocular trauma surveillance system in the United States makes it difficult for this information to be available to practitioners and researchers. Efforts to build and sustain such a system would facilitate higher-quality epidemiologic investigations in the future. Other efforts, such as incorporating ocular trauma in the Intelligent Research in Sight registry or reviving the US Eye Injury Registry, could produce the same benefit, making use of an already established platform. Furthermore, the data reported in our study are from 5 to 13 years ago, which can possibly affect the interpretation of results. However, despite these limitations, this study is the first, to our knowledge, to report the incidence and mechanisms of open globe injuries in the United States during a 9-year study period.

Quiz Ref IDThe incidence of open globe injuries in the United States seems to be decreasing. Fall-related open globe injuries, however, appear to continue to increase. The findings suggest that preventive resources should be targeted toward high-risk groups: young men, individuals with a low socioeconomic status, and those 70 years or older who are at increased risk of falls.

Accepted for Publication: November 20, 2019.

Corresponding Author: Fasika A. Woreta, MD, MPH, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, 600 N Wolfe St, Baltimore, MD 21218 (fworeta1@jhmi.edu).

Published Online: January 23, 2020. doi:10.1001/jamaophthalmol.2019.5823

Author Contributions: Mr Canner had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Mir, Srikumaran, Friedman, Woreta.

Acquisition, analysis, or interpretation of data: Mir, Canner, Zafar, Friedman, Woreta.

Drafting of the manuscript: Mir, Zafar, Woreta.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Mir, Canner, Zafar.

Administrative, technical, or material support: Mir, Canner.

Supervision: Woreta.

Conflict of Interest Disclosures: Dr Srikumaran reported receiving personal fees from Alcon and grants from the National Institutes of Health outside the submitted work. No other disclosures were reported.