The Effect of Oral Administration of 9-cis Rich Powder of the Alga Dunaliella Bardawil on Visual Functions in Adolescent Patients With Retinitis Pigmentosa

The Effect of Oral Administration of 9-cis Rich Powder of the Alga Dunaliella Bardawil on Visual Functions in Adolescent Patients With Retinitis Pigmentosa

The Effect of Oral Administration of 9-cis β Carotene Rich Powder of the Alga Dunaliella Bardawil on Visual Functions in Adolescent Patients With Retinitis Pigmentosa

The aim of this study is to determine whether 9-cis-beta Caroten rich D. Brdawiil extract is effective in the treatment of retinitis pigmentosa in adolescent patients.

Retinitis pigmentosa is a genetically disease consisting of progressive retinal degeneration starting in the rods. Its prevalence is 1:4000 people and is the fourth most common blinding disease in Israel in 2004 [7% of all blindness]. The investigators treated a non-progressive form of the disease [Fundus Albipunctatus] by oral therapy of the food supplement made from alga Dunaliella Bardawil composed of approximately 50% 9-cis β-carotene. The 9-cis β -carotene has been shown to be a precursor of 9-cis retinoic acid both in-vitro in human intestinal mucosa and in-vivo in a ferret, perfused with 9-cis b-carotene. The night vision, as measured objectively by electroretinography (ERG) more than doubled in six patients tested following treatment. The visual field was also improved significantly. In a more recent study the investigators treated 29 retinitis pigmentosa patients with the 9-cis b Carotene algae Dunaliella Bardawil in a double masked placebo control cross over trial. Significant improvement in retinal function was recorded in 34% of the patients. As a natural extension of this study we will perform a double-masked, randomized, crossover, placebo-controlled study for adolescent patients. Longer treatment duration will be tested: a 24 week treatment with either the 9-cis β-carotene-rich capsules or placebo followed by an additional a 24 week treatment with the other capsules and a wash-out period of 24 weeks between this two type of treatments. We predict that with this study design a maximal/increased therapeutic effect as well as efficient washout will be achieved.

15 patients will first receive the capsules containing the alga Dunaliella Bardawil 9-cis beta-Carotene rich powder (5mg/Kg) for 24 weeks. After 24 weeks of washout period they will receive capsule containing placebo (Starch) for 24 weeks.

The other 15 Patients will receive first the placebo (Starch) capsules for 24 weeks. After 24 weeks of washout period they will receive capsules containing the alga Dunaliella Bardawil 9-cis beta-Carotene rich powder .

Using the protocol of the International Society for Clinical Electrophysiology of Vision and the "UTAS 3000" system (LKC Technologies, Gaithersburg, MD), full-field electroretinographic responses will be recorded from both eyes of each patient. For scotopic conditions, maximal ERG b-wave responses will be recorded following 30 minutes of dark adaptation.

Kinetic visual field for chromatic stimuli will be recorded in both eyes after 30 minutes of dark adaptation. Area of vision within the isopter will be measured by software in cm2.

Kinetic visual field will be recorded in both eyes. Area of vision within the isopter will be measured by software in cm2.

Using the protocol of the International Society for Clinical Electrophysiology of Vision and the UTAS 3000 system (LKC Technologies, Gaithersburg, MD), full-field photopic electroretinographic responses will be recorded from both eyes of each patient.

Inclusion Criteria: Written informed consent to participate in the study. Adolescent 12-18 years old. Electroretinogram (ERG) responses compatible with the diagnosis of Retinitis Pigmentosa Exclusion Criteria: Currently a smoker Current use of vitamin A/ β-carotene supplements Active arterial disease within 3 months prior to enrolment in the study, e.g. unstable angina, myocardial infarction, transient ischemic attack, stroke, coronary artery bypass graft surgery History of malignancy, excepting basal or squamous cell skin carcinoma Females who are pregnant, or breast feeding, or are premenopausal but not using chemical or mechanical contraception Uncontrolled hypertension, defined either as resting diastolic blood pressure >95 mmHg (taken from the mean of 3 readings) or as resting systolic blood pressure >180 mmHg History of alcohol abuse or drug abuse or both Intention to engage in vigorous exercise or an aggressive diet regimen Uncontrolled endocrine or metabolic disease Participation in another investigational drug study within 4 weeks prior to enrolment Serious or unstable medical or psychological condition which, in the opinion of the PI, would compromise the subject's safety or successful participation in the study Initiation of hormone replacement therapy or oral contraceptive therapy within 3 months prior to enrolment

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