A team of researchers at Aalto University in Finland has unveiled a promising new treatment that may stop the disease’s progression in its early stages. The technique works by strengthening the protective mechanisms of retinal cells using heat, according to Professor Ari Koskelainen, who led the research.

“Cellular functionality and protective mechanisms weaken with age, which exposes the fundus—the inside surface at the back of the eye—to intense oxidative stress,” Prof. Koskelainen said. “Free oxygen radicals damage proteins, causing them to misfold and aggregate. Then fatty protein deposits called drusen begin to accumulate, which is the main diagnostic criterion for the dry form of age-related macular degeneration.”

The team’s approach involves heating retinal tissue by a few degrees, a process that must be done carefully: temperatures above 45°C can damage delicate eye tissue. To overcome this challenge, the researchers developed a method that allows real-time temperature monitoring while heating the tissue using near-infrared light. This innovation enables precise control and reduces the risk of injury. Beyond safety, the treatment taps into the healing power of heat at the cellular level.

“It harnesses the power of heat to trigger healing responses,” Prof. Koskelainen says.

Cells naturally combat misfolded proteins in several ways. One mechanism involves heat shock proteins, which help refold damaged proteins. If that fails, the proteins are broken down into amino acids. When accumulations have already formed, a process called autophagy—for which Yoshinori Ohsumi won the 2016 Nobel Prize in Medicine—is activated. In autophagy, cells encase damaged proteins in a lipid membrane, marking them for breakdown by lysosomal enzymes.

“We were able to show that we can activate not only the production of heat shock proteins but also autophagy using the heat shocks,” Prof. Koskelainen explains. “This process is similar to waste disposal.”

The new method has already been successfully tested in mice and pigs, and human clinical trials are scheduled to begin in Finland in spring 2026. The first phase will focus on confirming the safety of the approach rather than its therapeutic effect. If successful, researchers will proceed to determine how frequently the treatment needs to be repeated.

“The treatment needs to be repetitive, since the response can already begin to decline some days after the treatment,” says Prof. Koskelainen.

The study, published in Nature Communications on October 29, marks a major milestone in AMD research. To accelerate its path to patients, the team has also established a research-to-business start-up called Maculaser to commercialize the discovery.