Clinical Trial: Cone Rescue in Retinitis Pigmentosa by the Treatment of Lycium Barbarum

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Cone Rescue in Retinitis Pigmentosa by the Treatment of Lycium Barbarum

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.

Results: Lycium barbarum treatment provides the immediate effect and the persistent effect on retinal functions and structure in patients with retinitis pigmentosa to improve the cone activity. It does not cause any harmful effect to the subjects.

Conclusion: Cone rescue is an alternative approach to save the vision for RP patients. The result of this study will provide valuable information for the treatment of RP. The antioxidative effect of LB is believed to delay or minimize the cone degeneration in RP and the intake of LB will be a very economic way in the RP treatment.


Detailed Summary:
Sponsor: The Hong Kong Polytechnic University

Current Primary Outcome: Visual field sensitivity [ Time Frame: up to 18 months ]

Humphrey Visual Field Analyser will be used to measure the brightness sensitivity across the central visual field at time points of 0, 6, 12 and 18 months. The sensitivity (dB) 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


Original Primary Outcome: Visual field sensitivity [ Time Frame: up to 18 months ]

Humphrey Visual Field Analyser will be used to measure the brightness sensitivity across the central visual field at time points of 0, 6, 12 and 18 months


Current Secondary Outcome:

  • Amplitudes of electroretinogram [ Time Frame: 0, 6, 12 and 18 months ]
    The retinal electrical responses from electroretinogram will be measured at the time points of 0, 6, 12 and 18 months. The amplitude (uV) 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
  • Implicit times of electroretinogram [ Time Frame: 0, 6, 12 and 18 months ]
    The retinal electrical responses from electroretinogram will be measured at the time points of 0, 6, 12 and 18 months. The implicit time (msec) 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
  • ETDRS Visual Acuity [ Time Frame: 0, 6, 12 and 18 months ]
    The high contrast and low contrast Visual acuity will be measured at the time points of 0, 6, 12 and 18 months. The acuity (sec of arc) 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


Original Secondary Outcome: Electroretinogram [ Time Frame: 0, 6, 12 and 18 months ]

The amplitudes and implicit times of retinal electrical responses from electroretinogram will be measured at the time points of 0, 6, 12 and 18 months


Information By: The Hong Kong Polytechnic University

Dates:
Date Received: September 17, 2014
Date Started: November 2014
Date Completion: November 2017
Last Updated: February 22, 2017
Last Verified: February 2017