Researchers at Aalto University are testing a novel approach to stop age-related macular degeneration before it destroys vision: carefully controlled infrared heat that wakes up the eye's own repair systems.
The condition affects roughly one in three people over 80. About 20 million Americans age 40 and older live with some form of AMD, and the dry variant accounts for most cases. It creeps forward gradually, eroding central vision until reading, driving, and recognizing faces becomes impossible. Yet doctors have had few options to intervene early, before damage becomes permanent.
The Aalto team flipped the conventional approach. Rather than replacing cells after vision loss advances, they ask whether the eye can be coaxed into defending itself before the disease takes hold.
How the heat treatment works
The method uses precisely delivered near-infrared light to warm retinal tissue by just a few degrees. The goal is to trigger cellular defense mechanisms that naturally weaken with age, without harming the delicate structure of the eye.
Professor Ari Koskelainen explains the underlying problem. "Cellular functionality and protective mechanisms weaken with age, which exposes the fundus to intense oxidative stress," he says. Free radicals damage proteins, causing them to misfold and clump together. These fatty protein deposits, called drusen, accumulate at the back of the eye and mark the progression of dry AMD.
Heat itself is not new in medicine, but applying it to the retina is tricky. If temperature climbs above 45 degrees Celsius, tissue damage occurs. The researchers built a system that monitors temperature in real time while the infrared light warms the tissue, keeping treatment within a narrow safe zone.
The heat works as a controlled stress signal. When cells experience mild heat shock, they activate heat shock proteins, which help repair or discard damaged proteins. The treatment also triggers autophagy, a cellular cleanup system that breaks down and removes harmful material. That second process matters because protein deposits and cellular stress sit at the heart of dry AMD.
"We were able to show that we can activate not only the production of heat shock proteins, but also autophagy," Koskelainen says. "This process is like waste disposal."
Animal tests in mice and pigs demonstrated that controlled heating could activate these protective responses in retinal tissue. But human proof remains ahead.
First human trials set for 2026
Patient trials are planned to begin in Finland in spring 2026, starting with a focus on safety rather than vision improvement. If that phase succeeds, researchers will determine how often patients would need the procedure. Koskelainen notes that "the treatment needs to be repetitive, since the response can already begin to decline some days after the treatment," suggesting it could become a maintenance therapy delivered at intervals rather than a one-time fix.
The approach arrives as the dry AMD research landscape shifts. For years the condition was viewed as largely untreatable in early stages. The FDA recently approved Valeda Light Delivery System, a different light-based device for certain AMD patients. Unlike the Aalto method, Valeda uses photobiomodulation rather than retinal heating.
The Aalto research was published in Nature Communications in October 2025. A startup called Maculaser is working to bring the technology to market. Koskelainen said an optimistic timeline could see the treatment available in hospital eye clinics within three years, with a longer-term vision of bringing it to local ophthalmologists.
The promise is real but unproven. Animal models show the concept works. Human trials will test whether it is safe. If future studies confirm early results, a burst of precisely controlled laser heat could become a tool to help aging eyes repair themselves before vision slips away.
Author Jessica Williams: "This is the kind of prevention-first approach dry AMD desperately needed, though the three-year commercial timeline feels optimistic until the Finland trials actually show it works in patients."
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