Cone Rescue in Retinitis Pigmentosa by the Treatment of Lycium Barbarum
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Enrollment
- 50
- Locations
- 1
- Primary Endpoint
- ETDRS Visual Acuity (High Contrast)
Study Overview
Brief Summary
Objectives: To study the immediate effect and the persistent effect of Lycium barbarum (LB) treatment on retinal functions, especially the cone function, and retinal structure in patients with retinitis pigmentosa (RP) Design: Randomised controlled double-masked trial
Setting: Primary Care clinical trial
Participants: 120 RP subjects will be recruited from Ophthalmology department at The University of Hong Kong and the Retina Hong Kong. Interventions: Subjects will be randomly allocated to LB (treated with LB granules) or control (treated with placebo) groups for 1 year. After the 1st year, both groups will stop the treatment and all subjects will also have the same eye exam in 6-month period for the 2nd year.
Main outcome measures: The primary outcome is the total sensitivity scores of 30-2 & 60-4 programmes of Humphrey Visual Field Analysis (HVFA). The secondary outcomes are the b-wave amplitudes of Full-field Electroretinogram (ffERG) responses, the amplitudes of direct component and induced component of Multifocal Electroretinogram (mfERG), and the ETDRS visual acuity.
Detailed Description
The study was a randomized controlled trial with a double-masked, placebo-controlled design. All the subjects were randomly allocated into either LB (treatment) group or placebo (control) group.
All the eligible subjects had the eye examination, including VA using the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart, refractions, tonometry, external and internal ocular health assessments, and fundus photo-documentation. Three additional tests were conducted to investigate the functional and structural changes in the RP patients, including Ganzfeld Electroretinogram, Humphrey Visual Field Analyser (Zeiss, Dublin, USA) and Spectral-domain Optical Coherent Tomography (SD-OCT) (Heidelberg Engineering, USA).
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Double (Participant, Investigator)
Eligibility Criteria
- Ages
- 18 Years to 70 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Ocular conditions:
- •Retinitis pigmentosa;
- •best corrected VA LogMAR 0.20 or better;
- •Humphrey Visual Field Analysis (HVFA) 30-2 total mean defect > or = 250 Decibel;
- •Intra-ocular pressure (IOP) <21 mmHg;
- •van Herrick ratio < or = 0.5;
- •no other ocular diseases
- •Dietary conditions:
- •Fruit and vegetable intake <10 servings/day;
- •spinach or kale intake < or = serving/day;
- •dietary lutein intake < or = 5.4mg/day;
- •no intake of cod liver oil or omega-3 capsules;
- •dietary Lycium barbarum intake < or =10 fruits/week;
- •supplement intake < or = 5000 IU/day of Vit. A and < or = 30 IU/day of Vit. E;
- •alcoholic consumption < or = 3 beverages/day
Exclusion Criteria
- •BMI > 40;
- •intake of any anticoagulants (especially Warfarin),
- •pregnant or planning to be pregnant;
- •other clinically significant systemic diseases, eg. diabetes, liver disease and heart disease
Arms & Interventions
Lycium Barbarum
Daily Lycium Barbarum dosage: 10g of granules for 12 months
Intervention: Lycium Barbarum (Dietary Supplement)
Placebo
Placebo
Intervention: Placebo (Dietary Supplement)
Outcomes
Primary Outcomes
ETDRS Visual Acuity (High Contrast)
Time Frame: 12 months
The high contrast visual acuity will be measured at the time point of baseline and 12 months. Visual acuity is to measure the eye's ability to resolve fine detail with full refractive error correction. The change of acuity (sec of arc) between 12-month time point and baseline will be provided to show the effect of interventions. The changes of the treatment group will be compared with the changes of the placebo group to illustrate the treatment effect of Lycium Barbarum.
Secondary Outcomes
- Implicit Times of Flash Electroretinogram(12 months)
- Amplitudes of Flash Electroretinogram(12 months)
- Visual Field Sensitivity(12 months)
Investigators
Henry HL Chan, PhD
Associate Professor
The Hong Kong Polytechnic University