August 28, 2024 – Recently evidence has shown that a certain combination of vitamins and minerals can slow disease progression in individuals with later stages of dry age-related macular degeneration.
Age-related macular degeneration (AMD) is a standard eye disease that always occurs in people aged 50 and over and causes vision loss on account of damage to the macula, the central a part of the attention accountable for visual acuity. The disease works about 20 million people within the United States and nearly 200 million people worldwide.
And by 2040, nearly 300 million people worldwide may very well be affected by the disease as average life expectancy continues to extend and diagnostic methods improve.
There are two forms: “dry” and “wet”.
Late-stage dry age-related macular degeneration, also referred to as geographic atrophy, leads to a gradual lack of the retinal pigment epithelium, a single layer of cells in the attention that is important to the health and performance of the attention. It is a progressive and irreversible condition that may end up in a dark or blurry area in the middle of your vision, surrounding blind spots, and possibly complete lack of central vision.
The other late type of AMD is wet AMD. In wet AMD, abnormal blood vessels grow behind the macula, the small, rounded area in the back of the attention that's accountable for central vision, color vision, and high-quality details. These vessels can leak blood and other fluids, scarring the macula and causing rapid deterioration of central vision.
However, dry age-related macular degeneration is the way more common form, accounting for around 85-90% of cases. Although it's less severe than wet AMD, in advanced stages it may cause significant vision loss.
The dietary complement in query, called AREDS 2, consists of antioxidant vitamins and minerals, namely vitamins C and E, lutein, zeaxanthin, zinc and copper. This formula will be purchased over-the-counter mixed in ready-made tablets.
The latest study was led by Tiarnan Keenan, MD, PhD, senior clinician in retinal diseases on the National Eye Institute published in the magazine Ophthalmology in July. The study examined the unique retinal scans of participants who developed dry AMD in previous studies.
“The purpose of these original experiments wasn’t really to look at geographic atrophy or expansion rates. They took all of these retinal images, which meant we could look at the spread of geographic atrophy,” Keenan said.
This has profound implications for future treatment of dry age-related macular degeneration and should influence future clinical trials, he said.
Re-examining an old study
Keenan and other authors of the brand new study reviewed data from the unique studies and located that in those whose central vision was not already affected by geographic atrophy, the complement slowed the speed of expansion by about 55% in comparison with a median of three years.
Geographic atrophy begins within the perifoveal area of the attention, an area just outside the more central foveal region. The perifoveal region gets its name from the fovea, the central a part of the macula. After it begins to spread within the perifoveal area of the attention, geographic atrophy extends inward into the fovea, where it may cause probably the most damage.
Before Keenan's study, it was widely believed that the formula had little or no profit in treating advanced dry age-related macular degeneration. They found that micronutrient supplements slowed geographic atrophy through a natural phenomenon called “foveal sparing.” As the name suggests, fovea sparing occurs when geographic atrophy surrounds the fovea but doesn't affect the fovea itself, effectively saving it from atrophy.
Foveal sparing was not considered in the unique studies published in 2001 and 2013.
“When a patch of geographic atrophy occurs slightly off center, it extends up and down, but not to the center. So you start getting these weird atrophy configurations, like a horseshoe, where it curls around the center but doesn't incorporate it…where its growth into the centers is much slower for some reason,” Keenan said.
Keenan says his study was able to separate the supplement's components and then compare how each component performed on different aspects of age-related macular degeneration. Zinc appeared to be effective in reducing the risk of dry AMD developing into wet AMD, in which abnormal vessels grow into the back of the eye and damage the macula.
However, zinc did not appear to have much beneficial effect against geographic atrophy. Meanwhile, vitamins C and E showed the greatest effectiveness against the spread of atrophy, likely due to their antioxidant properties.
How knowledge changed over time
According to David A. Merle, MD, a retinal expert at the Institute of Ophthalmology at University College London, subtle changes toward the center of the retina may be missed in studies that do not specifically focus on the center-directed progression of geographic atrophy. Center-directed progression simply refers to the way geographic atrophy progresses through the retinal cells, for example from the outside to the inside or to the center of the retina in the eye.
“That was not known [the supplements] had an impact on geographic atrophy,” he said. “And the major reason for this might be the best way these metrics were constructed in the brand new study, because they were geared toward center-directed progression reasonably than general growth of the lesions.”
The results are “impressive” and encouraging, Merle said, particularly for those who want to avoid the use of more invasive therapies such as the recently approved complement inhibitors Syforvre and Izervay in the United States.
Both Syfovre and Izervay must be injected directly into the eye once a month or every two months on an ongoing basis. They prevent damage to retinal cells by calming the immune response and can slow the development of geographic atrophy by around 14-20%. However, complement inhibitors such as Syfovre and Izervay can cause inflammation, bleeding under the clear lining of the eye, blurred vision, and an increase in fluid pressure in the eye. Some patients even developed wet AMD after taking the medication.
Although complement inhibitors can slow the growth of geographic atrophy by about 14-20% versus about 55% for antioxidant supplements, the relevant studies report the difference for both treatment cycles in total Atrophic growth and do not focus on how growth slows towards the center of the eye.
The strong reduction in overall lesion growth caused by the antioxidant supplements is still relevant, but it remains to be seen how it compares directly to complement inhibitors. However, there is little to no risk with dietary supplements.
“Given that these complement inhibitors are not available outside the United States, carry some risks, and must be injected regularly, [these] Dietary supplements can be a good and immediately available treatment option. They are relatively safe. “You can take them without any major side effects, and if they prove so effective, these supplements could become the gold standard for geographic atrophy in the future,” Merle said.
Merle was quick to indicate that while he was very encouraged by these latest findings, there had not yet been a large-scale clinical trial, something Keenan hoped to do in the long run.
“It's important to remember that these studies were not specifically designed for this endpoint,” Merle said. But doctors shouldn't worry about prescribing supplements to their patients, even in the event that they have advanced types of the disease.
“We are not taking any real risk by advising patients to take these medications. So why not give it a try?” said Merle.
Disease prognosis and patient response
In clinical practice, it's difficult to evaluate disease progression in patients taking the supplements in comparison with those that didn't take them. Without a control group in on a regular basis clinical practice, there isn't a direct measurement of the extent of atrophy.
“It depends more on the individual case,” said Merle.
The prognosis may vary greatly from case to case, as age-related macular degeneration is a fancy disease. For lucky patients, after a certain degree of loss, their partially impaired vision may remain relatively the identical and progress very slowly, while for some the disease progresses to the center of the retina, where the fovea is situated. Protecting the fovea is an important goal of treatment.
Although the supplements cannot prevent the event of age-related macular degeneration or cataracts, researchers in previous clinical trials have found that the formula reduced progression from middle to later stages by about 25% in people at higher risk of developing advanced age-related macular degeneration. slows macular degeneration.
They also cannot prevent wet AMD. However, research suggests that the supplements could help at the very least delay the onset of wet AMD.