Macular Pigment and Glaucoma Trial

 

This is a research study looking at the effects of oral dietary macular pigment (MP) supplementation in an individual with glaucoma. MP is a naturally occurring pigment located at the back of the eye. MP plays an important role to maintain good visual function including glare sensitivity. We have found that patients with glaucoma have reduced MP levels in their eye, which is a new finding. Studies have shown that oral dietary MP supplement can increase MP profiles to a normal level. Here, we would like to study whether dietary MP supplementation will reduce glare symptoms, which is a common complaint among glaucoma patients. We would also like to understand whether dietary MP supplementation will have any impact on glaucoma and the individual’s quality of life.

 

Please read carefully.

 

WHAT IS THE PURPOSE OF THE STUDY?

Background

  • Glaucoma is a slowly progressive disease that causes irreversible blindness.
  • Glare is defined as difficulty seeing in the presence of a bright light.
  • Glaucoma patients often suffer from glare symptoms and the cause of this is poorly understood.
    • Macular pigment (MP) is an important and naturally occurring pigment at the macula, which is located at the back of the eye.
    • MP is made up of 3 dietary compounds, Lutein (L), Zeaxanthin (Z) and meso-Zeaxanthin (meso-Z).
    • It is believed that these plant compounds help protect the eye by absorbing UV and harmful blue light and neutralising free radicals (antioxidant).
    • MP is vital in maintaining eye health and has been shown to play a role in reducing glare symptoms.
    • Studies have shown that people with higher MP levels have less glare symptoms.
    • Clinical trials have shown that the level of MP in an individual can be increased after taking supplements containing L, Z and meso-Z.
    • Our research group has shown that glaucoma patients have lower MP levels.

 

Research Aims

  1. Determine whether oral supplementation of L, Z and meso-Z (MacuShield®) can rebuild their pigment profile to normal levels
  2. Determine whether glare symptoms can be improved by oral MP supplementation
  3. Determine the relationship between MP and visual function in glaucoma patients

 

WHY HAVE I BEEN CHOSEN?

All glaucoma patients under the care of Professor Colm O’Brien are invited to participate in this research study. We aim to recruit 120 glaucoma patients and 60 healthy controls.

 

Please ask if you do not understand or would like more information.

 

WHO IS ORGANISING THE RESEARCH STUDY?

This research study will be conducted by:-

Principal Investigator: Professor Colm O’Brien Consultant Ophthalmic Surgeon
Investigator: Dr. James Loughman Director, Macular Pigment Research Group,
Dublin Institute of Technology Vision Research Laboratory
Authorised Healthcare Professional: Dr. We Fong Siah Specialist Registrar in Ophthalmology

 

 WHAT WILL HAPPEN TO ME IF I TAKE PART?

At the start of the study, you will participate in a series of vision-related tests, complete questionnaires, and be supplemented with either a dietary MP supplement capsule (MacuShield®) or placebo. You will take 1 capsule daily, preferably with a meal. The duration of the study is 6 months. Tests will be carried out at baseline (time of recruitment) and repeated at 6 months. Some participants may be invited back for additional testing at 3 months as well. Therefore each participant will visit the clinic on 2 to 3 occassions. Each visit may vary from 60 minutes to 90 minutes long.

 

The enrolment into this study will be on a voluntary basis and you will not be paid. The vision-related tests will not cause any distress to you. No eye drops will be instilled and you will still be able to drive.

 

This is a randomised, double-blind study. It means that participants will be put into groups and compared. The reason for this is to prevent bias in the study. The computer will randomly assign each participant into the groups. A double-blind trial means that neither you nor your doctor will know which treatment group you are in. This will only be revealed at the end of the study. The chance of you getting the dietary MP supplement capsule (MacuShield®) or placebo is 50%. The placebo will be a dummy tablet that contains no active ingredient but looks exactly like MacuShield®. The placebo will contain sunflower oil only. You will only be informed the nature of your treatment (either MacuShield® or placebo) at the end of the study. The identity of the treatment will not be revealed before the study ends as this will jeopardise the research.

 

WHAT ARE MY RESPONSIBILITITES?

You’ll be tested at baseline (time of recruitment into the study). This involves participating in tests that will measure visual performance (visual acuity, contrast sensitivity, glare sensitivity, photostress recovery time, visual field test) and structural measurements (MP optical density, macular thickness). Research participants will also be required to fill out food questionnaire and glaucoma-related quality of life questionnaire.

 

Some participants may be asked to return at 3 months as well. The reason for this is because it takes up to 3 months to rebuild the MP levels and testing at this stage may give us more information. Finally, you’ll be required to return for a final visit at 6 months. All participants will have to be compliant with the treatment so that the data we get can be interpreted accurately. During the course of the study, Dr. Siah will contact you either by a phone call or a phone text message to remind you to take your capsules and to attend your clinic visits. At the 3 month and 6 month clinic visits, you are required to bring all remaining capsules with you.

 

WHAT IS MACUSHIELD®?

It is a unique eye supplement made from naturally occurring dietary carotenoids. It contains Lutein 10mg, Zeaxanthin 2mg and Meso-Zeaxanthin 10mg. Research has shown that if you take Meso-Zeaxanthin, the levels of MP will significantly increase especially at the center of your retina where the vision is the sharpest. It is currently routinely used to reduce the risk of progression of age-related macular degeneration.

 

ARE THERE OTHER WAYS OF TREATING MY CONDITION?

The use of this treatment will not affect your glaucoma management. This treatment is an additional supplement and is not intended to substitute your current glaucoma medication(s). The cause of glare symptoms among glaucoma patients is poorly understood and this research study may provide us with useful information.

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ARE THERE ANY DISADVANTAGES IN TAKING PART IN THIS RESEARCH STUDY? WHAT ARE THE POSSIBLE RISKS OF TAKING PART?

MacuShield® is a natural product that is widely available over the counter. There are no long term side effects to MacuShield® and has been tested safe for human consumption on a large scale clinical trial in Ireland. The only documented and uncommon short term side effect of Lutein supplementation in humans has been carotenodermia, which is a harmless and reversible skin hyperpigmentation. However, if you do develop any symptoms that you are concerned about, you should contact Dr. We Fong Siah at 087-6164411 or consult your GP.

 

WHAT ARE THE POSSIBLE BENEFITS OF TAKING PART?

You may or may not receive any direct benefit from taking part in the research study. However, information obtained during the course of the research study may help us understand better your conditon.We hope that the treatment that you get may reduce your glare symptoms. However, this cannot be guaranteed. The information we get from this research study may help us to treat future patients with glaucoma better.

 

IS MY DOCTOR BEING PAID FOR INCLUDING ME IN THE RESEARCH STUDY?

No

 

WILL PATIENT EXPENSES BE MET?

The enrolment into this study will be on a voluntary basis and you will not be paid.

 

WHAT HAPPENS WHEN THE STUDY ENDS?

You will be informed whether you were treated with MacuShield® or placebo.

 

ARE THERE ANY RESTRICTIONS ON WHAT I MIGHT EAT OR DO?

No. Your diet will not be restricted as a result of the study.

 

WHAT IF SOMETHING GOES WRONG?

MacuShield®has been widely used and is known to be safe. Regardless of this, if you have any cause to complain about any aspect of the way you have been approached or treated during the course of this research study, the normal Health Service complaints mechanisms are available to you.

 

CONFIDENTIALITY – WHO WILL KNOW I AM TAKING PART IN THE RESEARCH STUDY?

All information, which is collected about you during the course of the research will be kept strictly confidential. All information about you, which leaves the hospital, will contain no information as to your identity so that you cannot be recognised from it.

 

GP NOTIFICATION

Your GP will normally be informed that you are taking part in this study. If this is a problem for you, you should discuss it with your study researcher.

 

HOSPITAL RESEARCH ETHICS COMMITTEE APPROVAL

This research study has been approved by the Mater Hospital Research Ethics Committee.

 

WHAT WILL HAPPEN TO THE RESULTS OF THE RESEARCH STUDY?

The results will be published in a peer-reviewed ophthalmology journal. If you wish to receive a copy of the published results, please inform the study researcher.

 

PROCEDURE TO BE USED IF ASSISTANCE OR ADVICE IS REQUIRED

In the event of a research related injury or any other problems, you can contact Dr. We Fong Siah at 087-6164411. The Principal Investigator for this study is Professor Colm O’Brien and his direct telephone number is 01-8858616.

 

VOLUNTARY PARTICIPATION

It is up to you to decide whether to take part or not. Even if you do decide to take part, you are free to withdraw at any time and without giving a reason. This will not affect the standard of care you will receive. Your doctor will not be upset if you decide not to take part.

 

If you have already been involved in a drug trial within the past 3 months, you are not eligible to take part in this research study. If you are a woman of child bearing potential, you must be on contraception to be eligible to participate in this study. Glaucoma is a disease that is more prevalent in the elderly therefore we will expect to have research participants aged > 65 years old.

 

We thank you for taking time to read this information leaflet and sincerely appreciate your contribution in this research study. We need your participation as the more people we recruit into the study, the more information we can gather.

 

If you require any further information or have any query regarding this study, please do not hesitate to ask.  You may contact Dr. We Fong Siah at 087-6164411.

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