comes in all shapes and sizes. Whether it arises in the
chronic form of arthritis or the sudden squeeze of cardiac
arrest, pain is the main motivator for a visit to the
may now have to note the eye color of their patients before
choosing a procedure to treat them. New research has shown
that women with dark brown and hazel eyes respond
differently to pain than those with light blue and green
the 2014 annual meeting of the American Pain Society, Inna
Belfer, M.D., Ph.D., an associate professor of anesthesiology
at the University of Pittsburgh, presented a study possibly
linking eye color to variations in pain tolerance.
study sample consisted of 58 healthy pregnant women at Magee-Womens
Hospital of the University of Pittsburgh Medical Center.
Twenty-four women were placed in the dark group, and the
remaining 34 were placed in the light group. Dr. Belfer and
her team measured responses to pain before and after giving
birth through a variety of quantitative standard testing,
questionnaires and surveys.
results indicated that women in the dark group experienced
more dramatic response to pain with increases in anxiety and
sleep disturbances than those in the light group.
was a small pilot study to start off," said Dr. Belfer.
"All we know now is super limited a hypothesis about
why there is a difference at this point would be too
optimistic but this could be a next step in finding a
genetic background of pain."
eye color as a genetic biomarker for pain thresholds will be
advantageous for the medical community.
now we dont know who is going to feel more severe pain
after standard surgery or develop chronic pain," said Dr.
Belfer, "This is a problem for both patients who are
suffering and society."
a visible indicator of a genetic signature that predicts pain
tolerance will "help to identify those targeted patients,
and the earlier you can identify them, you will be in better
shape for the future."
not the first research that has related phenotypic differences
and pain. Multiple studies have correlated red hair to
resistance to pain blockers and requirements for higher doses
of anesthesia. Dr. Belfer and her team also discovered three
studies that link eye color to physiological activity.
Belfer plans to continue the research on this topic by
expanding to studies including men, children and larger, more
comprehensive distinctions between groups.