Social determinants of health as risk factors for keratoconus in the All of Us database

Background/aims: Clinical risk factors for keratoconus (KCN) have previously been established. While the impact of the social determinants of health on the epidemiology and pathophysiology of KCN has been explored, further study of these associations is needed in large and diverse populations. This cross-sectional study determines how education level and income impact the prevalence of KCN in the USA using the National Institutes of Health 'All of Us' database.

Methods: Exposures included the highest level of education and annual household income. Multivariable logistic regression was used to examine the odds of KCN diagnosis at different levels of education and income, adjusting for sex assigned at birth, race, ethnicity, age, atopic conditions and eyecare access.

Results: The overall prevalence of KCN was 0.17% (429/255 334). In multivariable logistic regression, individuals with more than a high school education had a greater risk of having KCN than those with less than a high school equivalent (college 1-3 years: adjusted OR (aOR): 1.96; 95% CI 1.46 to 2.65; college graduate or advanced degree: aOR:2.19; 95% CI 1.61 to 3.00). There were no significant associations between income level and odds of keratoconus.

Conclusion: In the study population, higher education level was associated with an increased likelihood of keratoconus, while no correlation was seen between income and KCN prevalence. After adjusting for access to eye care in a secondary analysis, there was an association between increased education level and increased prevalence of KCN. Further studies are needed to fully understand the mechanism of this finding such as increased levels of dry eye secondary to computer vision syndrome in highly educated people.