NEW YORK (Reuters Health) - Japanese men with higher blood
pressure were more likely to have impaired color vision, a new
study has found.
Researchers said that for now, it's not clear what explains
According to Dr. Saadia Rashid, damage to certain parts of
the eye that occurs as a result of high blood pressure could
ultimately lead to vision loss. It's possible that impaired
color vision could be a sign of future problems related to high
blood pressure, also known as hypertension, said Rashid, an
ophthalmologist from Montefiore Medical Center in New York.
But the new study represents just a snapshot in time, and
longer-term studies are needed to tease out the relationship,
"It will be great if acquired color vision impairment can be
a harbinger of future hypertension-related complications,
however it is premature to state that," Rashid told Reuters
Health. She was not involved in the research.
Knowing that high blood pressure has been tied to certain
eye diseases, Dr. Takuhei Shoji from Saitama Medical University
in Japan and colleagues evaluated the relationship between color
vision and eye disease, heart-related risk factors and lifestyle
The researchers recruited men ages 20 to 60 years old who
were on active duty in the Japanese Self Defense Force in Kyoto.
Shoji's team looked at the men's medical records, measured
their blood pressure and gave them two tests to assess how
accurately they could see and discriminate different colors.
Both tests involve lining up a certain number of caps in order
Of the 872 men included in the study, 130 failed one test
and 31 failed the other.
After the researchers took into consideration other factors
such as men's weight, cholesterol, blood sugar levels and other
eye diseases, they found that as blood pressure values rose, the
odds of having impaired color vision increased as well.
The researchers note that the study design does not allow
them to look at changes in vision or blood pressure over time.
The study also can't prove high blood pressure caused
impairments in color vision.
Still, "The data are useful and important for further
investigations of many of these associations," the authors write
in the American Journal of Hypertension.
"Color vision testing is a higher order visual function and
the authors have suggested looking into it as a future early
marker of hypertensive disease," Rashid said.
She said it's possible that by lowering their blood pressure
people could reverse acquired color vision problems, but more
research is necessary to determine that as well.
One concern she has is that tests for color vision function
are more complicated than the regular eye tests most people get
at the doctor. Color vision tests are time consuming and hard to
do because they require specific lighting conditions, so they're
not readily available.
"Future research is needed to popularize this idea, and
perhaps come up with simpler ways of checking color vision, on
modalities such as home smartphones and devices as a home
screening tool," Rashid said.
"We have to wait for the research to catch up," Rashid
added. In the meantime, she said, controlling high blood
pressure is "critical" to prevent vision problems and other
She said people can screen their color vision at home with
an online color test challenge, such as the one online here: http://bit.ly/1bMzPEW.
The challenge is similar to the tests used in this study.
SOURCE: http://bit.ly/1lc3G93 American Journal of
Hypertension, online June 4, 2014.