A/Prof Gerald Liew’s second MDFA Research Grant is allowing him to investigate a potential sight-saving supplement to improve dysfunctional mitochondria and prevent age-related macular degeneration (AMD).
The reasons why some people develop age-related macular degeneration (AMD) but others do not remain somewhat mysterious.
Associate Professor Gerald Liew suspects one cause might be dysfunctional mitochondria in cells of the eye.
Now, a Research Grant from Macular Disease Foundation Australia is giving A/Prof Liew the chance to investigate whether this hypothesis is true… and if it is, whether an oral supplement might be able to fix the problem and prevent irreversible vision loss.
“So the mitochondria are the powerhouses of the cell — like the batteries of the cell,” A/Prof Liew explains.
“We hypothesise that perhaps there’s a problem with them, and that’s why some people get macular degeneration and others do not.”
In this project, A/Prof Liew will collect blood samples from patients with atrophic or dry AMD and neovascular or wet AMD, as well as people of a similar age with no sign of disease.
His team will then analyse the blood to work out the markers that are different in these groups — features that tell us why some people develop disease, while others don’t.
An earlier study by A/Prof Liew tested patients’ blood for as many things as possible. The most promising signal he identified was that people who developed AMD were deficient in a particular chemical called carnitine, which helps power the mitochondria.
Now, this MDFA-funded project is drilling down on this hypothesis, and testing it against a larger group of people.
If our research bears fruit, and we find that this particular chemical really is low in the blood of patients with macular degeneration, then perhaps by supplementing it, we can help to delay or prevent macular degeneration. That’s what we’re working towards.A/Prof Liew
Encouragingly, this supplement already exists and is commercially available in Australia. Carnitine dietary supplements are popular among bodybuilders and found in health food stores.
Some people diagnosed with AMD benefit from AREDS2 supplements — and A/Prof Liew’s research could lead to another important ingredient being added to this formula.
“With AREDS2, we already know that certain combinations of vitamins and antioxidants are useful in delaying the onset of macular degeneration. So we think we may have identified another one that could be added to the mix,” A/Prof Liew says.
“It’s unlikely that oral dietary supplements alone would be enough to reverse macular degeneration. But if it could help prevent or delay the onset, that’s what we’re hoping for.”
An earlier MDFA Research Grant in 2015 allowed A/Prof Liew to conduct a similar study focused on neovascular AMD.
This 2023 funding builds on that earlier work, by exploring both the neovascular and atrophic forms of the disease.
The goal is to help prevent AMD in some people, delay the onset in others, and slow down progression among patients who’ve already been diagnosed.
“Particularly for patients with dry AMD,” A/Prof Liew adds.
“If the hypothesis holds up, that would be particularly useful because there remains no good treatment for dry macular degeneration.
“What do I hope to achieve for people living with macular disease? Well, of course, it’d be wonderful if we could cure it. But at this stage, I think what can realistically be achieved is prolonging the period of good vision by delaying the progression of macular degeneration as much as possible.”
When A/Prof Liew was choosing his medical specialty, he jokes that ophthalmology appealed to him because the lasers used to treat patients reminded him of playing a computer game.
More seriously, though, he was drawn to the chance to work with world-renowned ophthalmologist Prof Paul Mitchell at the Westmead Institute for Medical Research, University of Sydney, where he remains today.
A/Prof Liew did his PhD with Prof Mitchell, leading to more and more opportunities in retinal research under his mentor.
Despite these opportunities, A/Prof Liew admits that securing funding is still a “major obstacle” to research into potentially sight-saving discoveries.
Prof Mitchell was an inaugural MDFA Research Grant recipient when the program was established in 2011 to provide a dedicated stream of research funding into macular disease.
More than a decade later, A/Prof Liew describes MDFA’s Research Grant Program as “really the only game in town.”
“Prof Mark Gillies used that phrase a few years ago, and I think now it’s even more true. The problem is the funding environment has shifted quite decisively, and sadly, small organs like the eye have been have been left behind.
It’s extremely difficult to get NHMRC funding or funding from the large bodies, so I’m really grateful that MDFA has provided this opportunity.A/Prof Liew
A/Prof Liew reports that some of the macular disease patients he sees as an ophthalmologist actually donate to MDFA’s Research Grant Program, because they want to support research that will benefit future generations.
That’s why he’s so determined to find a breakthrough that could help stop people from losing their vision to macular disease.
“The impact of your donation goes far beyond what’s immediately visible,” A/Prof Liew says.
“And it will bear fruit, rest assured.”
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Published: 8 December, 2023