May 22, 2000
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.
Related Web sites:
Wilmer Eye Institute at Johns Hopkins: http://www.wilmer.jhu.edu
American Optometric Association: http://www.aoanet.org