The impact of social determinants of health has been well documented in many chronic diseases, including diabetes mellitus and cardiovascular disease.^1,2 The study, “Socioeconomic Correlates of Keratoconus Severity and Progression,”³ revealed the socioeconomic risk factors of keratoconus (KCN).

Here, I provide an overview of this study, and its value to corneal specialists.

Overview

This study, published in 2023 in Cornea, was a retrospective cohort study of 1,038 KCN patients who were assessed based on several social criteria. To accomplish this, the study’s researchers reviewed these patients’ EMRs for these socioeconomic traits: race, primary language spoken, insurance payer, and employment status.

Additionally, the researchers recorded the patients’ clinical characteristics, such as age, gender, BMI, and presence of comorbid conditions (e.g., diabetes, asthma/eczema, sleep apnea, and Down syndrome).

The study’s primary outcome measures were severity of KCN at presentation, KCN progression, and the need for corneal transplantation.

Results revealed:

• Non-White patients (odds ratio (OR) 1.83, P<0.001), non-English-speaking patients (OR 2.39, P=0.003), unemployed/disabled patients (OR 1.66, P<0.001), and patients insured by Medicaid (OR 2.00, P<0.001) were significantly more likely to have severe KCN (steep keratometry >52D) at presentation.
• Non-White patients (hazard ratio (HR) 1.34, P=0.04), Medicaid-insured patients (HR 1.38, P=0.05), patients younger than age 18 (HR 1.64, P=0.04), and male patients (HR 1.41, P=0.02) were at a significantly higher risk of KCN progression.
• Medicaid-covered patients were significantly more likely to present with severe KCN versus commercially insured patients.
• Medicaid-insured patients were at a significantly higher risk of requiring corneal collagen cross-linking (OR 2.09, P=0.001) and significantly less likely to obtain gas permeable or scleral contact lenses (OR 0.51, P=0.001) versus those who had commercial insurance.
• Medicaid-insured patients were significantly more likely to need a corneal transplantation (OR 3.38, P<0.001) versus commercially insured patients.

Value

Because KCN is a chronic, progressive disease that can lead to vision loss, it is imperative ophthalmologists evaluate these patients thoroughly. This study illustrates the importance of using socioeconomic risk factors to identify KCN patients who may be at a disproportionately higher risk of poor outcomes from the condition.

In particular, this study showed that Medicaid-insured patients are at a significantly higher risk of presenting with advanced KCN, KCN progression, and requiring corneal transplantation. Additionally, the study revealed that these patients have significantly lower rates of access to life-altering visual improvement through gas permeable or scleral lenses. CP

References:

1. Walker RJ, Smalls BL, Campbell JA, Strom Williams JL, Egede LE. Impact of social determinants of health on outcomes for type 2 diabetes: a systematic review. Endocrine. 2014;47(1):29-48.
2. Powell-Wiley TM, Baumer Y, Baah FO, et al. Social determinants of cardiovascular disease. Circ Res. 2022;130(5):782-799.
3. Ahmad TR, Kong AW, Turner ML, et al. Socioeconomic correlates of keratoconus severity and progression. Cornea. 2023;42(1):60-65.

DR. VAIDYA joined Chicago Cornea Consultants as a full-time associate in the summer of 2021. He is interested in corneal transplantation, refractive surgery, disorders of the eyelid, and oculoplastic surgery.