Light Therapy for Dry AMD: What Do We Know?

 

Newly authorized treatment has fans, but skepticism persists amid sparse data

Armed with a recent authorization from the FDA, eye specialists are offering light therapy to patients with non-exudative (dry) age-related macular degeneration (AMD), aiming to stop or even reverse vision loss. Proponents claim the treatment can be helpful, but the cost and burden are high, insurance coverage is iffy, and skeptics warn that data are sparse.

Dry AMD develops when parts of the macula "get thinner with age, and tiny deposits called drusen build up," according to the American Academy of Ophthalmology (AAO). The dry form accounts for 80% of patients with AMD, which affects an estimated 20 million people ages 40 and older in the U.S.

Treatments are available for dry AMD patients who also have geographic atrophy, but until the FDA's recent authorization of light therapy, those with dry AMD alone had no treatment options other than taking vitamins known as AREDS2 supplements that have been shown to decrease progression to neovascular (wet) AMD.

Light Therapy Makes a Splash

Photobiomodulation (PBM), which uses near-infrared wavelengths, has shown beneficial effects across multiple medical disciplines, including neurology, dermatology, and orthopedics, Christina Weng, MD, of the Baylor College of Medicine in Houston, told MedPage Today.

"The way PBM works has been ascribed to improving mitochondrial function by activating cytochrome C oxidase, decreasing inflammation, and promoting wound healing," Weng said.

LumiThera has been a pioneer in testing light therapy for AMD. The 24-month results of the phase III LIGHTSITE III study impressed attendees at the 2024 American Society of Retina Specialists meeting, and the FDA later authorized LumiThera's Valeda Light Delivery System.

The system is designed to generate light at different wavelengths to stimulate and improve the function of retinal mitochondria. Patients undergo nine sessions over 3 to 5 weeks, repeated every 4 months, study researcher Richard Rosen, MD, of the New York Eye and Ear Infirmary of Mount Sinai in New York City, told MedPage Today. Each session takes about 10 minutes and exposes the eyes to different wavelengths of light. Part of the treatment is delivered through closed eyelids, part with eyes open.

"It's very, very comfortable," Rosen said, adding that patients don't suffer from significant side effects.

How Much Difference Does the Treatment Make?

In the LIGHTSITE III trial, patients with dry AMD who received PBM gained on average 5.4 letters compared with 3.0 letters in the sham arm over approximately 2 years. The study also found a significant decrease in new-onset geographic atrophy and a reduction in drusen volume.

"It doesn't really eliminate the disease, but it does seem to push the clock back in terms of progression," Rosen said.

In terms of day-to-day impacts, patients "can see details when they're reading music or in a lot of their everyday activities, a lot of things that they had lost," he noted.

During follow-up, researchers "found that the patients who had been treated maintained their vision and the patients who had not been treated got a little bit worse," he said.

It's Still Unclear Who the Most Ideal Patients Are

As Rosen told MedPage Today in 2024, the system "is for early disease, patients who are just starting to lose vision, who have some drusen, and the vision is down maybe a line or two."

He recently elaborated that "the therapy targets patients with early vision loss -- typically those with 20/30 to 20/100 vision."

Still, Weng noted, "we are not yet able to identify which patients are likely to benefit the most from PBM."

She also cautioned that the LIGHTSITE study was small with just 100 patients, and five eyes in the PBM arm developed wet AMD versus one in the sham arm. "Future exploration into this observation is warranted," she said.

Light Therapy Is Costly, and Critics Aren't Convinced

A New York retinal clinic currently offers the treatment for nine visits at $2,500 for both eyes, or $2,025 for one eye, and it recommends 27 treatments per year. Insurers aren't yet covering light therapy in AMD, Rosen said.

As the AAO noted in a press release, the FDA hasn't officially approved the treatment, only granting authorization "based on early evidence that it is safe and works as intended. It's possible that some insurance providers won't cover the treatment if they view it as experimental or investigational."

In a viewpoint published in JAMA Ophthalmology, Srinivas R. Sadda, MD, of the David Geffen School of Medicine at the University of California Los Angeles, wrote that the LIGHTSITE III results lacked many important details. He also highlighted the small sample size and the treatment burden -- 27 office visits per year.

Andrew Morgenstern, OD, of the Walter Reed National Military Medical Center in Bethesda, Maryland, also expressed skepticism. "I'm not convinced that I know enough about light therapy for AMD yet or that a large majority [of eye specialists], even AMD specialists, are knowledgeable enough yet," he told MedPage Today.

He added that it's unclear whether the treatment could harm the eye by exposing it to light.

"There are segments of the spectrum of UV light that makes cataracts worse, and we know there are parts of the light spectrum that actually can advance AMD itself," he said.

Disclosures

Weng disclosed a relationship with Alcon, which recently acquired LumiThera.

Rosen reported relationships with Alcon, Visionix, Boehringer Ingelheim, Kyoto Drug Discovery and Development, Opticology, Guardion, Regeneron, Cellview, LumiThera, OcuSciences, Intalight, Topcon, and Cano.

Morgenstern had no disclosures.

https://www.medpagetoday.com/spotlight/aao-amd/119102