One-Year Outcomes of Oral Treatment With Alga Capsules Containing Low Levels of 9-cis-β-Carotene in RDH5-Related Fundus Albipunctatus

Abstract

This study aimed to clarify the effect of 1-year oral treatment with 9-cis-β-carotene-rich alga Dunaliella Bardawil (Dunaliella supplementation) using full-field electroretinography (ERG) in patients with RDH5-related fundus albipunctatus (FAP). Prospective interventional case series PARTICIPANTS: The study included 12 patients (23 eyes) with RDH5-related FAP. Twelve patients (23 eyes) with RDH5-related FAP received Dunaliella supplementation (total daily dose of β-carotene was 74.0 mg, comprising 28.4 mg 9-cis-β-carotene and 45.6 mg all-trans-β-carotene at a ratio of 1:1.6) for 1 year and underwent ophthalmic examinations, including full-field ERG at baseline, 3 months, and 1 year after the initial treatment. The main outcome was changes in the amplitudes of responses of full-field ERG before and after treatment. A linear mixed-effects model was used to evaluate the adjusted mean difference between the amplitude of each response pre-treatment and post-treatment. Prolonged dark adapted (DA) responses at 3 months revealed a significant impairment in the b-wave of DA 0.01 (adjusted mean difference; -34.7, 95% CI; -66.8 to -2.73, p = 0.041) and a-wave of DA 3.0 (-29.0, 95% CI; -50.6 to -7.41, p = 0.013) and DA10.0 (-40.4, 95% CI; -67.8 to -13.0, p = 0.007), which were also observed at 1 year. Additionally, prolonged DA and light adapted (LA) responses revealed statistically significant impairment at 1 year in the b-wave of DA 3.0 (-43.8, 95% CI; -82.9 to -4.78, p = 0.035), DA 10.0 (-59.7, 95% CI; -101.8 to -17.61, p = 0.009), LA 3.0 (-7.31, 95% CI; -13.6 to -1.04, p = 0.029), and in LA 3.0 flicker (-7.53, 95% CI; -12.7 to -2.34, p = 0.007). Our study results suggest that Dunaliella supplementation comprising low levels of 9-cis-β-carotene compared with those reported in a previous study (1:1 ratio) adversely affects ERG amplitudes in patients with RDH5-related FAP.