Treatment of a retinal dystrophy, fundus albipunctatus, with oral 9-cis-β-carotene

Background: Fundus albipunctatus is a retinal dystrophy caused by a mutation in the gene encoding 11-cis-retinol dehydrogenase which delays the recovery of rod photoreceptor cells from light stimulation leading to night blindness. A recent study of a mouse model of fundus albipunctatus treated with 9-cis-retinal showed an improvement in visual function and structure. Methods: Seven patients with fundus albipunctatus were given a daily food supplement of four capsules containing high-dose 9-cis-β-carotene for 90 days. The subjects were tested before and after treatment by visual field and electroretinogram in both eyes. This nonrandomised prospective phase I study was registered at http://www.clinicaltrials.gov (NCT00478530). Results: All patients showed significant improvements in peripheral visual field (mean deviation improved from -4.7762.0 to -3.28±2.28, p=0.009, t test) and a highly significant improvement in rod recovery rates measured electroretinographically (maximal scotopic bwave amplitude responses, improved from 197±49 μV to 292±48 μV, p<0.001, t test). No complications or side effects were observed. Conclusion: Oral treatment with 9-cis-β-carotene led to reversal of a human retinal dystrophy. This potential therapy is readily available and should be evaluated in retinal dystrophies of similar mechanisms such as various types of retinitis pigmentosa.