Study: Lutein and Retinitis Pigmentosa (2006)
Nutrient Supplementation for RP
Retinitis pigmentosa (RP) refers to a group of inherited progressive retinal dystrophies characterized by photoreceptor degeneration. The rods are affected initially, followed by gradual death of the cones. It's estimated that 1 in 4,000-5,000 people have RP worldwide. Since no generally accepted medical or surgical treatment can stop the course of the disease, researchers have undertaken studies with various nutritional supplements in hopes of improving visual function or slowing disease progression. Along with vitamin A, DHA and an omega-3 rich diet, lutein has recently been reported to be of potential benefit in RP.
Lutein May Benefit Visual Field and Acuity Spurred by previous studies suggesting lutein as a potential treatment with positive effects on macular pigment density, researchers from the Wilmer Eye Institute conducted a double-blind, randomized placebo-controlled trial with a cross-over design (1). Thirty four adult RP patients were randomized to 2 groups and followed for 48 weeks. One group received lutein supplements (10 mg/day for 12 weeks followed by 30 mg/day) for the first 24 weeks, then placebo for the following 24 weeks. The second group received placebo prior to lutein. Both groups were given a multi-vitamin and mineral supplement.
Lutein supplementation had a significant effect on central visual field. Visual acuity also improved slightly, though no effect on contrast sensitivity was observed. Comparing the development of vision measures against the natural loss expected to occur over 48 weeks, most measures showed reduced decline. These reductions were significant for normal illumination visual acuity and contrast sensitivity. The results, according to the authors, suggest that lutein supplementation improves visual field and may also modestly improve visual acuity.
H, et al. Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized double-masked placebo-controlled clinical trial. BMC Ophthalmology 6:23, 2006.