Cone Rescue in Retinitis Pigmentosa by the Treatment of Lycium Barbarum

January 28, 2019 updated by: Henry HL Chan, PhD, The Hong Kong Polytechnic University

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.

Study Overview

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 Type

Interventional

Enrollment (Actual)

50

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Hong Kong, Hong Kong
        • The Hong Kong Polytechnic University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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;
  • smoking;
  • other clinically significant systemic diseases, eg. diabetes, liver disease and heart disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
Placebo
Experimental: Lycium Barbarum
Daily Lycium Barbarum dosage: 10g of granules for 12 months
Traditional Chinese Herbs
Other Names:
  • Wolfberry

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.

12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Visual Field Sensitivity
Time Frame: 12 months

Humphrey Visual Field Analyser will be used to measure the brightness sensitivity across the central 30 degree visual field at time point of baseline and 12 months. Visual field is to measure the size of the field of view and the sensitivity of the corresponding locations of the field of view.

The change of sensitivity (dB) between 12-month time point and baseline will be provide to show the effects 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

12 months
Amplitudes of Flash Electroretinogram
Time Frame: 12 months

The cone responses from electroretinogram will be measured at the time point of baseline and 12 months. The cone response is related to the activity of the cone photoreceptor under light stimulation.

The change of cone response b-wave amplitude (uV) between 12-month and baseline will be provided to show the effect of interventions. The b-wave amplitude is to measure the magnitude of electrical responses of cone cells in the retina.

The changes of the treatment group will be compared with the changes of the placebo group to illustrate the treatment effect of Lycium Barbarum.

12 months
Implicit Times of Flash Electroretinogram
Time Frame: 12 months

The cone responses from electroretinogram will be measured at the time point of baseline and 12 months. The cone response is related to the activity of the cone photoreceptor under light stimulation.

The change of cone response b-wave implicit time (ms) between 12-month and baseline will be provided to show the effect of interventions. The b-wave implicit time is to measure the physiological changes of cone cells in the retina.

The changes of the treatment group will be compared with the changes of the placebo group to illustrate the treatment effect of Lycium Barbarum.

12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2014

Primary Completion (Actual)

April 1, 2016

Study Completion (Actual)

November 1, 2017

Study Registration Dates

First Submitted

September 17, 2014

First Submitted That Met QC Criteria

September 18, 2014

First Posted (Estimate)

September 19, 2014

Study Record Updates

Last Update Posted (Actual)

February 19, 2019

Last Update Submitted That Met QC Criteria

January 28, 2019

Last Verified

January 1, 2019

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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