Findings from a recent study published in Eye reported changes in the prevalence of pediatric and adult optic neuritis (ON) in the United States.
Give me some background.
Optic neuritis is characterized by inflammation of the optic nerve with a variety of underlying etiologies. It typically manifests with:
- Unilateral, sudden, painful vision loss
- Decreased color vision and contrast sensitivity
- Relative afferent pupillary defect
Note: Data on the prevalence of ON is limited, with reported rates between 5.5 and 115.3 per 100,000.
- In fact: U.S. data is even more limited, with the largest study performed in a single county, demonstrating a prevalence of 115.3.
Meaning: “Available data on the prevalence of ON in the US is sparse, outdated, and not generalizable to the entire U.S. population, underpinning the need for our analysis,” the study authors noted.
Now talk about the study.
In this cross-sectional study, investigators analyzed data from 2016-2023 and included 14,870 patients (mean age 52 years, 60.7% female) with International Classification of Diseases, Tenth Revision (ICD-10) codes of:
- Retrobulbar neuritis (H46.1)
- Other ON (H46.8)
- Unspecified ON (H46.9)
Why: These codes were chosen to most accurately reflect primary ON that was not secondary to another cause.
The data collection: Assembled through a series of queries in the TriNetX platform, which contains deidentified electronic health record (EHR) data from over 113 million patients.
Findings?
In 2023, the prevalence of ON was 51.5 per 100,000 people in the overall population.
Females had 1.31 increased odds (95% confidence interval [CI] 1.27-1.36) of disease compared to males.
- Note: The reported ON prevalence was 54.3/100,000 for females and 41/100,000 for males.
Were there differences in ON prevalence based on race or ethnicity?
In 2023, the racial and ethnic breakdown of ON prevalence was as follows:
- Black populations: 57.8/100,000 (odds ratio [OR] 1.06, 95% CI 1.01-1.10)
- White populations: 54.7/100,000 (reference data)
- Hispanic or Latino populations: 45.8/100,000 (OR 0.84, 95% CI 0.79-0.89)
The prevalence of ON increased 1.08 times (95% CI 1.05-1.10) from 2016 to 2023, with the greatest increase seen in the Hispanic population.
How did age impact ON prevalence?
Stratified by age, those aged 45-54 years had the highest prevalence (71.3/100,000) of ON.
Significant increases in ON prevalence were also observed in the following age groups:
- 0-14 (2.96-fold increase)
- 15-24 (1.53-fold increase)
- 25-34 (1.51-fold increase)
Expert opinion?
One potential reason why females had a 31% increased odds of ON compared to males “is a greater prevalence of demyelinating diseases like multiple sclerosis (MS) in females,” the study authors explained.
Limitations?
These included:
- There were meaningful differences in representation between the TriNetX database and the general U.S. population
- This included an underrepresentation of Latino patients and an overrepresentation of patients from the Northeast, among other discrepancies
- Information on race and ethnicity may be self-reported or recorded by a provider—potentially leading to errors
- Some small subpopulation counts were rounded to 10 due to TriNetX’s deidentification requirements
- This resulted in the rounding of all counts 1-9 to 10, limiting the ability to draw fully accurate conclusions about certain subpopulations
- The reliance on ICD-10 diagnosis codes, which may not always be accurately applied in clinical settings and could not be verified by the authors
- Patients with ON signs/symptoms who were not able to be seen and diagnosed by a specialist were excluded
Take home.
These findings demonstrated racial, ethnic, and sex disparities in the distribution of ON, with Black patients and females being most often affected and an increasing prevalence reported in the Hispanic population.
Younger subpopulations also exhibited significant increases in ON prevalence, warranting additional investigation to identify the driving force behind the increasing rates.