乌鸦传媒視頻

Previous estimates of visual impairment have yielded mixed results due to differences in factors such as study design.¹ Nevertheless, data from national health surveys and population-based studies have revealed a possible disproportionate distribution of ophthalmic disease among vulnerable populations, including non-White individuals and those with lower socioeconomic status.^2-4

To better understand the extent of visual impairment in the U.S. population and to improve the generalizability of research findings, U.S. investigators conducted a retrospective, observational study that assessed impaired visual acuity, blindness, and potential risk factors, using the American Academy of Ophthalmology IRIS (Intelligent Research in Sight) registry, among patients in ophthalmology practices across the nation. Their findings were published in a recent issue of Ophthalmology.¹

The researchers found a prevalence of 6.98% for visual impairment and 0.98% for legal blindness and identified older age, public or no insurance, minority race/ethnicity, smoking, and rural areas as key risk factors for blindness. Racial/ethnic minorities and underinsured individuals appeared to be underrepresented in ophthalmology practices and overrepresented among patients who were blind. 

鈥淭hese findings provide a unique and comprehensive snapshot of the population of United States patients receiving care in ophthalmic practices,鈥� the authors commented in their report, 鈥渁nd suggest potential areas for improving patient outreach and use of care among vulnerable populations.鈥�¹

Analyzing IRIS

The research team analyzed 2018 data from approximately 19.5 million patients with visual acuity records available in the IRIS registry, currently the largest clinical single-specialty dataset in the country. Visual impairment (20/40 or worse) and legal blindness (20/200 or worse) were determined based on the distance-corrected visual acuity in the better-seeing eye and analyzed according to patient characteristics. 

Data from other population records, namely 2018 U.S. Census estimates and the National Health and Nutritional Examination Survey (NHANES) in 2007 and 2008, were used as part of the analysis. 

Impaired vision was evident in about 1.4 million (6.98%) IRIS patients and blindness in 190,817 (0.98%).

Risk of blindness by patient characteristics

Older age: Risk of blindness was highest among patients at least 85 years of age, compared with those 0-17 years of age (odds ratio [OR] 11.85; 95% confidence interval [CI] 10.33-13.59). 

Underinsured and minorities: An increased risk of blindness was apparent among patients with Medicaid (OR 3.85; 95% CI 3.57-4.15), no insurance (OR, 1.77; 95% CI 1.37-2.27), and Medicare (OR, 1.66; 95% CI 1.53-1.82), compared to those with commercial insurance. 

鈥淥ur findings鈥�suggest that the mere presence of some form of health insurance is not sufficient to address risk of blindness,鈥� the authors commented. 

Race/ethnicity: The risk of blindness was also increased among Black patients (OR 1.73; 95% CI 1.63-1.84), Hispanic patients (OR 1.59; 95% CI 1.46-1.74), and those in the mixed or unspecified racial/ethnic groups (OR 1.43; 95% CI 1.24-1.65), compared with White patients. There was no significant difference in risk of blindness between White and Asian patients. 

Smoking: Those who smoked had an elevated risk of blindness (OR 1.13; 95% CI 1.08-1.17). 

Rural locations: Those in rural areas also had a greater risk of blindness (OR 1.09; 95% CI 1.04-1.14). The authors noted that rural Western states, especially Alaska, Montana, South Dakota, and Wyoming, demonstrated the highest risk of blindness. 

Sex: No significant difference in risk of blindness was apparent between males and females. 

Representation in IRIS

Overall, 6.63% of White individuals were represented in the IRIS Registry versus 3.77% and 1.46% of Black and Hispanic individuals, respectively. Specifically, representation was 2-to-4 times greater for White than for Hispanic individuals and 11% to 85% greater for White than for Black individuals, depending on the age group analyzed (P<.001 for both comparisons). Underrepresentation, the extent of which varied by age, was also evident for Asian versus White individuals. 

NHANES versus IRIS

The overall prevalence of blindness was significantly lower in NHANES than the IRIS registry. The researchers pointed out that, among those 60 years of age or older, Black individuals had the lowest prevalence of blindness in NHANES at 0.54%, but the second highest in IRIS at 1.57%; this latter percentage was comparable to the prevalence for Hispanic individuals (1.60%) but notably higher than for White individuals (1.11%). 

In closing鈥�

In their conclusions, the authors noted that 鈥淭hese potential disparities may have substantial impact because patients with poor vision are at increased risk for falls, depression, inability to drive or live independently, and unemployment as well as increased mortality. Identifying and addressing the underlying reasons for disproportionately low use of eye care and disproportionately high prevalence of blind patients in vulnerable populations will be a critical public health priority.鈥�

Published: December 06, 2023