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Treatment of Bardet-Biedl-Syndrome With Metformin for Evaluation of a Possible Visual Improvement

Phase 2
Withdrawn
Conditions
Visual Impairment
Bardet-Biedl Syndrome
Interventions
Registration Number
NCT03490019
Lead Sponsor
University Hospital Tuebingen
Brief Summary

In this prospective pilot study without control group children and young adults (10-25 years old) diagnosed with Bardet-Biedl syndrome and treated with Metformin for their adipositas will be evaluated for a possible additional effect of Metformin on visual acuity.

Detailed Description

Within experiments with animals a positive effect of Metformin concerning the photo receptors was shown. Several patients of the university hospital Tübingen with Bardet-Biedl-Syndrome and Metformin therapy due to their adipositas reported a subjective improvement of the visual acuity which was confirmed by opthalmologic tests.

This will be checked in a prospective pilot study without control group including children and young adults (10-25 years old) diagnosed with Bardet-Biedl syndrome and treated with Metformin for their adipositas. Therefore a possible additional effect of Metformin on visual acuity will be evaluated under controlled conditions.

Recruitment & Eligibility

Status
WITHDRAWN
Sex
All
Target Recruitment
Not specified
Inclusion Criteria
  • clinically confirmed Bardet-Biedl-syndrome
  • Visual acuity between 0.05 and 0.8
  • Age >=10 year to <25 years
  • Visual field III4e or V4e with diameter >=5°, if II4e not seen
  • informed consent of patient and/or legal representative
Exclusion Criteria
  • Hypoglycaemia (<50mg/dl)
  • Therapy with Metformin within the last three months
  • Participation in another clinical trial
  • pregnancy, lactation
  • any contra indication concerning Metformin therapy
  • Renal failure (creatinine clearance < 60ml/min)
  • any acute disorder accompanied by clouding of consciousness
  • acute or chronic disorders possible accompanied by tissue hypoxia
  • Liver insufficiency, alcohol abuse
  • not fluent in German language

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Metformin TherapyMetforminMetformin therapy once daily for 24 weeks with a dose of 500, 850 or 1000 mg depending on body weight
Primary Outcome Measures
NameTimeMethod
Visual acuityBaseline to day 210

Course of visual acuity according to appropriate table

Secondary Outcome Measures
NameTimeMethod
Visual evoked potential (VEP) - latency timeBaseline to day 210

Course of results of measurement of VEP latency time

Electroretinogram (ERG) 30-Hz-FlickerBaseline to day 210

Course of values of ERG measured by 30-Hz-Flicker in all patients

FSTBaseline to day 210

Full-Field-Stimulus Threshold

Number of letters readBaseline to day 210

Course visual acuity defined as number of letters read

Results of Kinetic perimetryBaseline to day 210

Course of results of kinetic perimetry given by mapping the visual field sensitivity boundaries using Goldmann perimetry

Electroretinogram (ERG) standard flashBaseline to day 210

Course of values of ERG standard flash at 3 ods/m2

Results of Static perimetryBaseline to day 210

Course of results of static perimetry given by measurement of light contrast sensitivity within at least 5 central points.

Electroretinogram (ERG) dim-flashBaseline to day 210

Course of values of ERG dim-flash

Electroretinogram (ERG) cone-single-flashBaseline to day 210

Course of values of ERG cone-single-flash at 30cd/m2

Visual evoked potential (VEP) - amplitudeBaseline to day 210

Course of results of measurement of VEP amplitude

optical coherence tomography (OCT)Baseline to day 210

Course of central thickness of retina measured by OCT

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