Abstract / Summary
Background and Objectives: Amblyopia is traditionally considered a pediatric condition; however, it may persist into adulthood and remain underrecognized. We examined the associations between sociodemographic and systemic factors and claims-documented amblyopia prevalence in the 2019 California (CA) Medicare population. Materials and Methods: This cross-sectional study used 2019 CA Medicare claims data for 2,649,107 beneficiaries aged ≥65 years, with Part A and B coverage, and valid ZIP codes for Social Vulnerability Index (SVI) values. Amblyopia was identified using ICD-10-CM diagnosis codes (H53.0x) in Medicare claims. Exposures included age, sex, race and ethnicity, systemic disease burden measured by Charlson Comorbidity Index (CCI) score, and Centers for Disease Control and Prevention SVI quartile. Logistic regression assessed associations between these factors and amblyopia diagnosis; descriptive statistics characterized refractive error and strabismus distribution by amblyopia status. Results: Amblyopia was present in 8460 (0.3%) beneficiaries. The largest proportions were aged 65–69 (n = 737,527; 27.8%), identified as female (n = 1,509,401; 57.0%), and were non-Hispanic White (n = 1,660,167; 62.7%). In adjusted models, increased odds of amblyopia were associated with ages 70–84 years, with the highest odds at ages 75–79 (age 75–79 vs. 65–69 adjusted odds ratio [aOR]: 1.42, 95% CI: 1.33–1.51), female sex (aOR: 1.10, 95% CI: 1.05–1.15), and a higher CCI score (CCI score ≥ 5 vs. 0 aOR: 1.30, 95% CI: 1.21–1.40). Decreased odds were associated with age ≥ 85 years (aOR: 0.88, 95% CI: 0.81–0.95), racial and ethnic minoritization (Black vs. Non-Hispanic White aOR: 0.51, 95% CI: 0.44–0.59), and a higher SVI quartile (Q4 vs. Q1 aOR: 0.67, 95% CI: 0.62–0.71). Conclusions: Ages 70–84 years, female sex, and higher systemic disease burden were associated with increased likelihood of amblyopia, while age ≥ 85 years, racially and ethnically minoritized groups, and those with higher social vulnerability had a decreased likelihood of documented amblyopia. Further research is needed to examine factors affecting amblyopia screening, diagnosis, and treatment in conjunction with comorbid ocular diseases in the elderly, including whether these differences reflect disparities in healthcare access and diagnostic coding rather than true differences in prevalence.