Press Release: John Hopkins
University
A substance found in dark green leafy vegetables and egg
yolks may improve vision in people with retinitis pigmentosa
(RP) and other degenerative eye conditions, according to a
study published by a Johns Hopkins researcher, whose subjects
were recruited from the Internet and tested via e-mail.
Twelve of the 16 study participants with retinal
degenerative conditions reported that taking daily supplements
of the substance, called lutein, over a six-month period
significantly improved their vision. Lutein is an antioxidant
needed by the retina (the light-sensitive layer in the back of
the eye) to neutralize the damaging effects of short
wavelength light and free radicals. Study results were
published in the March issue of Optometry: Journal of the
American Optometric Association.
Study participants were recruited after a member of an
international retinal degeneration patient e-mail list noted
that several of her electronic pen pals said their vision
improved after adding lutein supplements to their diets. She
then asked Gislin Dagnelie, Ph.D., an assistant professor of
ophthalmology at Hopkins' Wilmer Eye Institute, for help in
designing vision tests for a study of the supplement.
The subjects took lutein supplements with
breakfast every day for six months, 40 mg/day for nine weeks
and 20 mg/day thereafter. Half of the participants also took
500 mg/day of DHA (a fatty acid found in fish oil), vitamin B
complex and digestive enzymes. Ten of the participants who
already were taking vitamin A and/or beta carotene continued
to take those supplements. They tested their vision on eye
charts sent as e-mail attachments and on wall charts they were
instructed to create, and returned data via weekly e-mails to
the study coordinators.
Besides the increase in visual acuity and
visual field size among most patients, the researchers noticed
that blue-eyed participants had substantially higher gains in
vision than dark-eyed participants. In addition, those who
took vitamin A and/or beta carotene supplements prior to the
study seemed to benefit more than those who did not. The
long-term effects of lutein supplements on the progression of
RP should be studied, Dagnelie says, and may explain the
results seen in this study.
While lutein needs more rigorous study in
direct observation of patients, Dagnelie says, scientists
should not underestimate the potential of the Internet to
conduct low-risk studies, particularly in cases where
specialized equipment is not needed to monitor results. He
adds that it is very important for participants in such
studies to be under local medical supervision, even if no side
effects are anticipated.
About 100,000 people have RP, a condition
that, over time, causes loss of night vision and peripheral
vision. Patients with severe RP eventually lose all their
sight.
