Addressing the disparities in access in areas of lower employment and educational attainment is crucial to ensuring equitable access to eye care services for all populations, study suggests. Photo: Getty Images.

Studies have shown that eyecare providers (ECPs) are distributed unequally across the United States, with some suggesting that the disparity has increased over the years. The authors of a new study sought to investigate this at the zip code level and found many factors impact where ECPs choose to practice, including local quality education, cost of living, job opportunities and the presence of academic centers.

Data from the 2020 Centers for Medicare and Medicaid Services and American Community Survey were used to examine locations of 47,949 providers (17,631 ophthalmologists and 30,318 optometrists) and corresponding local socioeconomic variables (education, employment and income). The number of optometrists in the study is smaller than the total number of practicing ODs because the data primarily captures providers who participate in Medicare/Medicaid.

Optometrists in the study were found to be more evenly distributed across both urban and rural areas, whereas ophthalmologists were concentrated in metropolitan areas where there is greater access to advanced medical facilities and hospitals.

Among patient variables, higher unemployment and lower educational attainment are associated with lower expected ECP availability, whereas there is unexpectedly greater ECP availability in areas with lower median household income, the researchers noted in their article on the work for Translational Vision Science & Technology. Population density, market demand, health care infrastructure, availability of resources and historical patterns of health care delivery influences where the ECPs are located.

For every 1% increase in percentage of population over 25 years with a bachelor’s degree or higher, the expected number of providers increases by 4.4%. For every 1% increase in percentage unemployment, the expected number of providers decreases by 2.7%. However, for every $1,000 increase in median household income, the expected number of providers decreases by 1.6%.

“Areas with lower median household income often have a higher proportion of individuals eligible for Medicaid and other safety net programs,” the authors explained in their paper. “Additionally, market forces may influence the distribution of health care providers such as potentially increased patient volume, lower overhead costs in lower income areas or lower competition in areas of lower income.”

The usage of land may also differ between areas with lower median household income and higher median household income. “Land from areas of higher median household income may be allocated for larger residential properties, leaving less availability for ECPs,” the researchers noted. “In addition, ECP data for areas of higher median household income may not be available if they are only accepting private insurances. These factors can be complex and may not be directly correlated with the income levels of an area.”

The authors suggest that further studies are needed to examine regional differences in urban vs. rural areas. Although there may be a higher concentration of ECPs in areas of lower median household income, disparities in access to eye care services can still exist.

“Affordability, insurance coverage, transportation and other barriers can limit the ability of individuals in these areas to access the eye care they need, despite the presence of providers,” the authors concluded. “Addressing these barriers comprehensively is crucial to ensuring equitable access to eye care services for all populations.”

Tran MT, Gonzalez VV, Mead-Harvey C, Shen JF. Insights into eye care accessibility: geospatial distribution of eye care providers and socioeconomic factors by zipcode. Transl Vis Sci Technol. 2024;13(3):21.