Treatment With 9-cisβ-Carotene–Rich Powder in Patients With Retinitis Pigmentosa

Abstract

IMPORTANCE 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. OBJECTIVE To determine the effect of oral treatment with 9-cis β-carotene on visual function of patients with RP. DESIGN Randomized, double-masked, placebo-controlled, crossover clinical trial. SETTING University tertiary medical facility. PARTICIPANTS 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. INTERVENTIONS Patients were treated daily for 90 days with capsules containing 300 mg of 9-cis β-carotene-rich 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. MAIN OUTCOMES AND MEASURES The primary outcome was 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. RESULTS The mean change in dark-adapted maximal b-wave amplitude relative to initial baseline was +8.4 μV for 9-cis β-carotene vs −5.9 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 −3.0% 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. CONCLUSIONS AND RELEVANCE 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. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01256697

Effectiveness and safety of nutritional supplements in the treatment of hereditary retinal dystrophies: a systematic review

“…Finally, 8 studies informed in 13 articles were included in the present review. [9][10][11][12][13][14][15][16][17][18][19][20][21] Characteristics of studies…”

“…All are randomised controlled trials, with a parallel design, 9,10,13,14,16 a crossover design, 11,19,18 or a factorial design. 12 Except Lee et al which studied Best disease, 18 all included studies are on RP.…”

“…12 Except Lee et al which studied Best disease, 18 all included studies are on RP. [9][10][11][12][13][14][15][16][17][19][20][21] They assessed supplements based on vitamin A and vitamin E, 12 docosahexaenoic acid (DHA), 9,10,14,16,18 and the carotenoids lutein, 11,13 and β-carotene. 19 We did not identify eligible studies about other HRDs.…”

“…18 The study by Bahrami et al has an important limitation regarding the method used for data recording, as they were documented by participants on their own using their personal computers. 11 All studies performed intention-to-treat analysis with the exception of Rotenstreich et al 19 Figure 1 Flowchart for the selection of studies. …”

“…13 Finally, another carotenoid, 9-cis-β-carotene from Dunaliella alga, was supplemented for 3 months on a crossover basis in the study by Rotenstreich et al, allowing a 3-month washout period between treatments. 19 Visual acuity Table 3 summarises the results for visual acuity. Berson et al reported a decline of visual acuity per year in all groups, with the larger decline in the group supplemented with both Vitamin A and E; however, the authors reported no significant differences among the four study arms (P-values were not reported).…”