Findings from a study recently published in Ophthalmology Science compared differences in glaucoma subtype, patient characteristics, and treatment between American Indians or Alaska Natives and other demographic groups.
Give me some background.
American Indian or Alaska Native individuals make up ~2.6% of the United States population and are disproportionately affected by health conditions such as:
- Cardiovascular disease
- Hypertension
- Diabetes
- Cirrhosis
- Poor mental health
Why: Disparities in healthcare from a history of colonialism, racism, and discrimination—resulting in a documented lack of access to care.
Anything to note from prior research?
Previous studies on glaucoma in American Indian or Alaska Native patients compared to the general U.S. population have provided mixed results, with some suggesting increased prevalence and others suggesting similar rates.
- However: These studies primarily evaluated patients >40 years of age and were limited to regional studies or individual tribes.
As such: Details regarding subtypes, incidence, and characteristics of glaucoma among American Indian or Alaska Native patients remain unclear on a broader scale.
Now talk about the study.
In this retrospective observational study, investigators utilized the Intelligent Research in Sight (IRIS) Registry to collect electronic health record (EHR) data on incidence and patient characteristic data from individuals with a glaucoma diagnosis between Jan. 1, 2011 and Dec. 31, 2020.
How: By including all patients with International Classification of Diseases, 9th and 10th editions (ICD-9 and ICD-10) diagnosis codes for the following types of glaucoma:
- Primary open-angle glaucoma (POAG)
- Juvenile open-angle glaucoma (JOAG)
- Pigmentary glaucoma (PG)
- Pseudoexfoliation glaucoma (PXG)
The following glaucoma treatments of the treating physician were evaluated for each subtype: selective laser trabeculoplasty (SLT), microinvasive glaucoma surgery (MIGS), incisional glaucoma surgery, and inferred subspecialty.
And what was measured?
Three main outcomes:
- Glaucoma incidence by subtype and race and ethnicity
- Incidence of incisional procedures, MIGS, and SLT in American Indian or Alaska Native patients
- Adjusted odds ratio (OR) for the likelihood of PXG and pigmentary glaucoma based on race and ethnicity
Next up: the findings.
The research team identified 6,270 American Indian or Alaska Native patients with incident glaucoma (0.34%).
Compared to other non-white demographic groups, American Indian or Alaska Native patients were over three times more frequently affected by PXG (4.49% vs. 1.60%) and PG (1.37% vs. 0.49%).
More American Indian or Alaska Native glaucoma patients underwent MIGS (15.24%) compared with patients of other races and ethnicities, with more MIGS procedures performed by a glaucoma specialist (33.9%).
Tell me more…
After adjusting for confounders, American Indian or Alaska Native patients had the highest odds of PXG diagnosis (OR: 2.12, 95% confidence interval [CI]: 1.85-2.42) compared to other demographic groups, and the second-highest odds of PG (OR: 1.33, 95% CI: 1.14-1.56).
Moreover: PG was more often diagnosed at younger ages (35-44 years old) among American Indian or Alaska Native patients.
Expert opinion?
“The higher percentage of MIGS and incisional surgery in [this] population could suggest more aggressive and severe disease in American Indian or Alaska Native patients at initial presentation, requiring earlier surgical intervention, as well as referral to a glaucoma specialist,” the study authors explained.
Any limitations?
A few, including:
- Data from academic medical centers was not included in the IRIS registry and practices that utilize paper charts were underrepresented
- As with other EHR analyses, there was a possibility of inaccurate documentation or misclassification
- While systemic disease covariates were included in the analysis, practices participating in the IRIS Registry may work in a private setting where extensive information regarding systemic comorbidities may not be available
- Some incident glaucoma cases in the study could be representative of prevalent disease
Take home.
These findings suggest that American Indian or Alaska Native patients have a notably increased burden of PG and PXG; however, due to the relatively smaller population size, these groups are historically less studied and may not be recognized as higher-risk.
- “Limited access to care, increased percentage of surgical interventions, and increased treatment by glaucoma specialists argue for focused examinations, earlier screenings, and appropriate referrals for American Indian or Alaska Native patients,” the study authors added.