U.S. Latinos Have High Rates of Eye Disease and Visual Impairment
Latinos living in the United States have high rates of eye
disease and visual impairment, according to a research study,
and a significant number may be unaware of their eye disease.
This study, called the Los Angeles Latino Eye Study (LALES),
is the largest, most comprehensive epidemiological analysis
of visual impairment in Latinos conducted in the U.S. It was
funded by the National Eye Institute (NEI) and the National
Center on Minority Health and Health Disparities (NCMHD), two
components of the Federal government's National Institutes of
Health (NIH). Study results are published in the June, July
and August 2004 issues of the journal Ophthalmology.
Researchers found that Latinos had high rates of diabetic retinopathy,
an eye complication of diabetes; and open-angle glaucoma, a
disease that damages the optic nerve.
Study investigators gave a detailed health interview and clinical
examination to more than 6,300 Latinos, primarily Mexican-Americans,
aged 40 and older from the Los Angeles area, assessing their
risk factors for eye disease and measuring health-related and
vision-related quality of life. Each participant received a
blood test for diabetes and a comprehensive eye exam that included
photographs of the back of the eye.
"This research has provided much needed data on eye disease
among the fastest growing minority group in the United States,"
said Elias A. Zerhouni, M.D., director of the NIH.
"Several epidemiological studies have been conducted on
the prevalence and severity of major eye diseases in White and
Black populations, however there have been relatively few such
studies in Latino populations," said Paul A. Sieving, M.D.,
Ph.D., director of the NEI. "This study highlights the
importance of providing health education and vision care to
Latinos."
The researchers noted that many study participants did not
know they had an eye disease. One in five individuals with diabetes
was newly diagnosed during the LALES clinic exam, and 25 percent
of these individuals were found to have diabetic retinopathy.
Overall, almost half of all Latinos with diabetes had diabetic
retinopathy. Among those with any signs of age-related macular
degeneration (AMD), a condition that can lead to a loss of central
vision, only 57 percent reported ever visiting an eye care practitioner,
and only 21 percent did so annually. Seventy-five percent of
Latinos with glaucoma and ocular hypertension (high pressure
in the eye) were undiagnosed before participating in LALES.
"Because vision loss can often be reduced with regular
comprehensive eye exams and timely treatment, there is an increasing
need to implement culturally appropriate programs to detect
and manage eye diseases in this population," said Rohit
Varma, M.D., M.P.H., associate professor of ophthalmology and
preventive medicine at the Keck School of Medicine's Doheny
Eye Institute at the University of Southern California, and
director of the study. "This is especially true when you
consider that Latinos, compared with other ethnic groups in
the U.S., have a high prevalence of low vision, diabetic retinopathy
and glaucoma. Overall, Latinos were much more likely to have
received general medical care than to have received eye care."
The study found that:
- Three percent of LALES participants were visually impaired,
defined as best corrected visual acuity of 20/40 or worse in
the better seeing eye, and 0.4 percent were blind, defined as
best corrected visual acuity of 20/200 or worse in the better
seeing eye. Prevalence rates of visual impairment in Latinos
are higher than those reported in Whites and comparable to those
reported in Blacks. Visual impairment increased with age. Those
in their 70s and 80s were up to eight times more likely to have
visual impairment than their younger counterparts. Other risk
factors for visual impairment included female gender, low education,
unemployment, a history of eye disease, and diabetes.
- Nearly half of all study participants with diabetes almost
a quarter of the LALES population had some signs of diabetic
retinopathy. Longer duration of diabetes was associated with
a higher risk of retinopathy. In addition, more than 10 percent
of participants with diabetes had macular edema (fluid buildup
in the back of the eye), of whom 60 percent had cases severe
enough to require laser treatment. Latinos had a higher rate
of more severe vision-threatening diabetic retinopathy than
Whites.
- The overall prevalence of open-angle glaucoma among
Latinos in this study was nearly five percent. This rate increased
with age from about eight percent for those in their 60s to
15 percent for those in their 70s. This is higher than the rate
reported for Whites and similar to that for Blacks in this country.
Nearly four percent of Latinos had ocular hypertension, a risk
factor for glaucoma.
- About 10 percent of participants were considered to be at risk
for progression to more advanced stages of AMD, and close to a
quarter of these individuals had signs of AMD in both eyes. Only
25 individuals had advanced AMD, a prevalence rate of 0.5 percent.
Age was a strong predictor for development of more advanced stages
of AMD. While Latinos had the early signs of AMD at rates comparable
to Whites, the rates of advanced AMD were lower than seen in Whites
and comparable to Blacks.
- One in five adult Latinos had cataract. Half of Latinos
with cataract or other clouding of the lens were visually impaired.
- Latinos with visual impairment based on the study eye
examination reported lower visual function on a questionnaire.
In particular, those whose vision had worsened by two lines
or more on a standard eye chart were more likely to report a
lower quality of life.
"Census 2000 data show that 12.5 percent of residents
in this country, or 35 million people, are Latino," said
John Ruffin, Ph.D., director of the NCMHD. "That number
is projected to increase to 61.4 million by the year 2025. This
study re-affirms the significance of eye disease and visual
impairment among Latinos, and its importance to public health,"
Ruffin said.
In addition to support from the NEI and NCMHD, the LALES was
supported by Research to Prevent Blindness, Inc.
The National Eye Institute (NEI) conducts and supports research
that leads to sight-saving treatments and plays a key role in
reducing visual impairment and blindness. The NEI is part of
the National Institutes of Health (NIH), an agency of the U.S.
Department of Health and Human Services.
The NIH's National Center on Minority Health and Health Disparities
(NCMHD) conducts and supports research, training, information
dissemination and other programs aimed at reducing the disproportionately
high incidence and prevalence of disease, burden of illness,
and mortality experienced by certain American populations, including
racial and ethnic minorities and other groups with disparate
health status, such as the urban and rural poor.
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