The Role of Macular Pigment Carotenoids in the Pathogenesis and Treatment of Macular Telangiectasia Type 2 (MacTel)

This study is ongoing, but not recruiting participants.
Sponsor:
Information provided by (Responsible Party):
Paul S. Bernstein, University of Utah
ClinicalTrials.gov Identifier:
NCT01354093
First received: May 12, 2011
Last updated: June 11, 2014
Last verified: June 2014
  Purpose

Macular telangiectasia type 2 ("MacTel Type 2") is an uncommon eye disorder that results in slow vision loss beginning in middle age. The macula is the central part of the retina, which lines the back of the eye like the film of a camera. The macula is responsible for central or reading vision. Telangiectasis refers to dilated, leaky vessels, for example varicose veins in the legs. One of the earliest manifestations of macular telangiectasia type 2 is an acquired reduction and/or redistribution of the macular pigment carotenoids at the foveal center. Currently, the biochemical mechanisms and clinical significance underlying these changes are not known, but it seems likely that better understanding of this phenomenon could lead to new interventions against MacTel.

The objectives of this study are to image the maculas of MacTel subjects using two-wavelength autofluorescence imaging and resonance Raman imaging to target the 7-degree radius pigment ring characteristic of macular telangiectasia type 2 in order to gain further insight into the significance of this early clinical sign, and to evaluate whether supplementation with oral zeaxanthin can normalize macular pigment distribution in MacTel subjects


Condition Intervention
Idiopathic Juxtafoveal Telangiectasia
Drug: zeaxanthin

Study Type: Observational
Study Design: Time Perspective: Prospective
Official Title: Utah Center for the Collaborative Study of the Role of the Macular Pigment Carotenoids in the Pathogenesis and Treatment of MacTel

Further study details as provided by University of Utah:

Primary Outcome Measures:
  • Change from baseline in macular pigment distribution and concentration [ Time Frame: 1 year ] [ Designated as safety issue: No ]
    The primary outcome measure will be will be change from baseline in macular pigment distribution and concentration.


Secondary Outcome Measures:
  • Change in visual acuity [ Time Frame: 1 year ] [ Designated as safety issue: No ]
    Secondary outcome measures will be best-corrected visual acuity, contrast sensitivity, and changes in retinal thickness measured by spectral domain OCT (optical coherence tomography).


Estimated Enrollment: 10
Study Start Date: November 2011
Estimated Primary Completion Date: July 2015 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
MacTel Type 2 20 mg/day dose group
Participants will have macular telangiectasis type 2 as confirmed by the reading center. Participants will take 20 mg of zeaxanthin per day.
Drug: zeaxanthin
10 mg of EyePromise 10 (zeaxanthin) supplement, taken twice a day
MacTel Type 2 10 mg/day dose group
Participants will have macular telangiectasia type 2 as confirmed by the reading center. Participants will take 10 mg of zeaxanthin per day.
Drug: zeaxanthin
10 mg of EyePromise 10 (zeaxanthin) supplement, taken once a day

Detailed Description:

One of the earliest manifestations of macular telangiectasia type 2 ("MacTel") is an acquired reduction and/or redistribution of the macular pigment carotenoids at the foveal center. Currently, the biochemical mechanisms and clinical significance underlying these changes are not known, but it seems likely that better understanding of this phenomenon could lead to new interventions against MacTel.

Dr. Bernstein's laboratory at the Moran Eye Center of the University of Utah has focused for the past fifteen years on the role of the macular pigment carotenoids, lutein and zeaxanthin, in maintaining macular health. These xanthophyll carotenoids are derived exclusively from the diet, especially from green leafy vegetables and orange-yellow fruits and vegetables. They are thought to protect the macula from light-induced oxidative damage by virtue of their light-screening and antioxidant properties. Dietary supplement products, from infant formula to those aimed at seniors, primarily contain lutein; however the central macula (the fovea) actually has been shown to have higher concentrations of zeaxanthin.

Dr. Bernstein's lab has identified and characterized the binding proteins responsible for the uptake and stabilization of lutein and zeaxanthin in the macula, developed new, noninvasive methods to quantify and image carotenoids in the retina and many other non-ocular tissues, and has participated in intervention trials of lutein and zeaxanthin against age-related macular degeneration. As a leading site for identification of MacTel families in North America as part of the "MacTel Project", Dr. Bernstein and other researchers at the University of Utah have unique expertise in the biochemistry and biophysics of the macular pigment carotenoids that may help to hasten progress toward effective diagnosis and intervention against MacTel in a highly collaborative manner.

Macular Pigment Imaging:

Dr. Bernstein has extensive experience with various methods to image and quantify macular pigment in the living human eye, especially using autofluorescence imaging (AFI) and resonance Raman imaging (RRI). Dr. Bernstein is also currently utilizing these methods to evaluate age-related macular degeneration (AMD) patients participating in the "AREDS2" study.

The objectives of this study are two-fold:

  1. To image the maculas of MacTel subjects using two-wavelength autofluorescence imaging (AFI) and resonance Raman imaging (RRI) to target the 7-degree radius pigment ring characteristic of macular telangiectasia type 2 in order to gain further insight into the significance of this early clinical sign;
  2. To evaluate whether supplementation with oral zeaxanthin can normalize macular pigment distribution in MacTel subjects.

This is an open-label pilot study that will enroll up to ten patients affected with macular telangiectasia type 2 and evaluate them every six months for two years. All participants will take 20 mg of zeaxanthin supplement per day for the duration of the study. Macular pigment distributions will be determined using two-wavelength autofluorescence imaging and resonance Raman imaging.

  Eligibility

Ages Eligible for Study:   50 Years to 85 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Up to ten subjects of either gender who have MacTel (as confirmed by the MacTel central study Reading Center) will be invited to participate. Only those who can conveniently travel to the University of Utah for study evaluations will be approached since the project does not have sufficient funding to reimburse for travel expenses. Participants must agree to discontinue use of any other supplements containing substantial amounts of carotenoids for one month prior to the baseline visit and for the duration of the study.

Criteria

Inclusion Criteria:

  • Male or female subjects who have MacTel and can conveniently travel to the University of Utah for study evaluations
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01354093

Locations
United States, Utah
Moran Eye Center, University of Utah
Salt Lake City, Utah, United States, 84132
Sponsors and Collaborators
Paul S. Bernstein
Investigators
Principal Investigator: Paul S. Bernstein, M.D., Ph.D. University of Utah
  More Information

Additional Information:
Publications:

Responsible Party: Paul S. Bernstein, Professor of Ophthalmology, University of Utah
ClinicalTrials.gov Identifier: NCT01354093     History of Changes
Other Study ID Numbers: 48834
Study First Received: May 12, 2011
Last Updated: June 11, 2014
Health Authority: United States: Food and Drug Administration

Keywords provided by University of Utah:
MacTel
Macular telangiectasia type 2

Additional relevant MeSH terms:
Telangiectasis
Vascular Diseases
Cardiovascular Diseases
Carotenoids
Antioxidants
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Protective Agents
Physiological Effects of Drugs

ClinicalTrials.gov processed this record on August 19, 2014