A recent study of inpatient open-globe injuries in the United States found patients with one or more of these characteristics over-represented: individuals over 85 years old, young males, elderly females, patients of African-American descent, those on Medicare and those in the lowest income category.

The retrospective cohort study included patients with a primary diagnosis of open-globe injury in the National Inpatient Sample from 2009 to 2015. The researchers used 2010 census data to calculate annual incidence.

The researchers identified a total of 6,821 inpatient hospital discharge records that met their study criteria. They then calculated the estimated annual incidence over the five-year study period to be 1.58 per 100,000 people per year. Overall, these rates were highest among those 85 and older (7.71), those on Medicare (3.92), males (2.28), African Americans (2.38) and Native Americans (1.8). Rates were lowest among white people (1.21), females (0.89), those with private insurance (0.84) and Asians (0.69). Additionally, the researchers noted that young children had lower rates of open-globe injury than adolescents.

“This study’s results demonstrate the open-globe injuries requiring hospital admission are more prevalent among individuals with lower socioeconomic status as defined by insurance status or income and disproportionately impact minority populations,” the researchers wrote in their paper. However, they noted that their estimate of annual rate was lower than has been previously reported. “While we found an estimated 34,061 open globe injuries over a seven-year period, prior literature estimates over 12,000 individuals suffer an open-globe injury per year in the US. This disparity is likely multifactorial.”

The researchers theorized that factors may include the fact that their study assessed only inpatients, not outpatients, “thus resulting in an underestimation of the overall rate of open globe injuries in the US.” They also noted that public health improvements, more stringent workplace safety requirements, use of protective eyewear during sports and other activities, and firearm and automobile safety legislation likely led to a decline in the overall injury rate, “which is consistent with our trend toward a decreasing number of open globe injuries per year during our seven-year study.” The team concluded that further studies are needed to “delineate causes for socioeconomic differences in injury rates to guide future public health measures.”