subject: Retinitis Pigmentosa and Lutein [print this page] A report published in Archives of Ophthalmology showed that non-smoking sufferers of RP experienced a reduction in the rate of loss of vision following treatment with the protein lutein. The study divided its sample into two groups, one of which was given 10mg of lutein a day for 12 weeks, and then 30mg of lutein a day for 24 weeks, while the other group were given a placebo for 24 weeks, then lutein at 30mg for 24 weeks.
In both the studied groups, it was shown that there is a 6-week delay experienced between the start of taking lutein and it having any effects on the patient. It was further shown that the reduction in loss of vision was greatest in visual acuity (clarity of sight) and contrast sensitivity.
Lutein is already present in the light receptor cells in the retina and it is believed to serve as an antioxidant. A different study, carried out in year 2000 showed similar results, but also showed that people with blue eyes as well as those that were taking vitamin A (in a beta-carotene form, rather than in retinyl palmitate used in the current study) supplements experienced the greatest reduction in their vision loss.
There are concerns over the validity of this research though, especially as the authors of the paper used linear methods to predict loss of vision, where retinitis pigmentosa may not cause linear loss of sight. Other concerns have been raised over the safety of taking high doses of vitamin A for extended periods of time, as the study only showed that lutein is safe to take for extended periods of time in the short term.
