beta-carotene and Retinitis-Pigmentosa

Retinitis pigmentosa (RP) is the leading cause of incurable inherited blindness in the developed world, with an estimated prevalence of 1 in 3500 individuals. Therefore, it is important to develop new treatments for this disease.. To determine the effect of oral treatment with 9-cis β-carotene on visual function of patients with RP.. Randomized, double-masked, placebo-controlled, crossover clinical trial.. University tertiary medical facility.. Thirty-four patients with RP who were at least 18 years of age. Twenty-nine patients completed the study and were included in the analysis.. Patients were treated daily for 90 days with capsules containing 300 mg of 9-cis β-carotene-ich alga Dunaliella bardawil (β-carotene, approximately 20 mg) or placebo (starch). Following a 90-day washout period, they were treated for 90 days with the other capsules.. The primary outcomewas the change for both eyes from baseline to the end of each treatment in dark-adapted maximal electroretinographic b-wave amplitude. The secondary outcomes were the changes in light-adapted maximal b-wave amplitude, dark- and light-adapted visual field, and best-corrected visual acuity.. The mean change in dark-adapted maximal b-wave amplitude relative to initial baseline was +8.4 μV for 9-cis β-carotene vs −.9 μV for placebo (P = .001). Ten participants (34.5%) had an increase of more than 10 μV for both eyes (range, 11-42 μV) after 9-cis β-carotene treatment compared with no participants after placebo treatment. The percentage change in light-adapted b-wave response was +17.8%for 9-cis β-carotene vs −.0% for placebo (P = .01). No significant differences were found between the groups for visual field and best-corrected visual acuity. No adverse effects were observed.. Treatment with 9-cis β-carotene significantly increased retinal function in patients with RP under the tested conditions. The optimal therapeutic regimen will be determined in future, larger clinical trials. 9-cis β-Carotene may represent a new therapeutic approach for some patients with RP.. clinicaltrials.gov Identifier: NCT01256697.

Topics: Administration, Oral; Adult; Aged; beta Carotene; Chlorophyta; Cross-Over Studies; Dark Adaptation; Double-Blind Method; Electroretinography; Female; Humans; Light; Male; Middle Aged; Powders; Retina; Retinitis Pigmentosa; Treatment Outcome; Visual Acuity; Visual Fields; Vitamins; Young Adult

The retinoid cycle enzymes regenerate the visual chromophore 11-cis retinal to enable vision. Mutations in the genes encoding the proteins of the retinoid cycle are the leading cause for recessively inherited retinal dystrophies such as retinitis pigmentosa, Leber congenital amaurosis, congenital cone-rod dystrophy and fundus albipunctatus. Currently there is no treatment for these blinding diseases. In previous studies we demonstrated that oral treatment with the 9-cis-β-carotene rich Dunaliella Bardawil algae powder significantly improved visual and retinal functions in patients with retinitis pigmentosa and fundus albipunctatus. Here we developed a convenient and economical synthetic route for biologically active 9-cis-β-carotene from inexpensive building materials and demonstrated that the molecule is stable for at least one month. Synthetic 9-cis-β-carotene rescued cone photoreceptors from degeneration in eye cup cultures of mice with a retinoid cycle genetic defect. This study suggests that synthetic 9-cis-β-carotene may serve as an effective treatment for retinal dystrophies involving the retinoid cycle.

Topics: Animals; beta Carotene; Cells, Cultured; Chemistry Techniques, Synthetic; Disease Models, Animal; Mice; Photoreceptor Cells, Vertebrate; Provitamins; Retinal Degeneration; Retinal Diseases; Retinitis Pigmentosa

Topics: beta Carotene; Female; Humans; Male; Retinitis Pigmentosa; Vitamins

Topics: beta Carotene; Cardiovascular Diseases; Cataract; Humans; Lung Neoplasms; Lutein; Macular Degeneration; Radiodermatitis; Retinitis Pigmentosa; Xanthophylls; Zeaxanthins

It has been hypothesized that the macular carotenoid pigments lutein and zeaxanthin may protect against macular and retinal degenerations and dystrophies.. To test this hypothesis by objectively measuring lutein and zeaxanthin levels in a noninvasive manner in patients who have retinitis pigmentosa (RP), choroideremia (CHM), and Stargardt macular dystrophy and comparing them with an age-matched healthy control population.. Using resonance Raman spectroscopy, a novel objective noninvasive laser-optical technique, we measured macular carotenoid levels in 30 patients (54 eyes) who have RP, CHM, and Stargardt macular dystrophy and compared them with 76 age-matched subjects (129 eyes) who did not have macular pathologic conditions in a case-control study.. As a group, patients with RP and CHM had the same macular carotenoid levels as age-matched healthy control subjects (P =.76, 2-way analysis of variance). Patients with Stargardt macular dystrophy tended to have levels of macular carotenoid pigments that, on average, were about 50% lower than healthy controls (P =.02,unpaired 2-tailed t test).. The patients with RP and CHM had normal levels of macular carotenoids, suggesting that nutritional supplementation with macular carotenoids such as lutein, zeaxanthin, or both will be unlikely to affect the clinical course of RP and CHM. Although the number of patients with Stargardt macular dystrophy examined was limited, their macular carotenoid levels were usually lower than those of subjects of a similar age with no macular pathologic condition.

Topics: Adult; beta Carotene; Choroideremia; Female; Humans; Lutein; Macular Degeneration; Male; Middle Aged; Retinal Pigments; Retinitis Pigmentosa; Spectrum Analysis, Raman; Xanthophylls; Zeaxanthins

Topics: Aged; Alcoholism; beta Carotene; Cholagogues and Choleretics; Female; Humans; Liver Cirrhosis; Retinitis Pigmentosa; Ursodeoxycholic Acid

Topics: Adaptation, Ocular; beta Carotene; Blood; Carotenoids; Eye; Head; Humans; Intestinal Absorption; Metabolism; Retinitis Pigmentosa; Vitamin A Deficiency