Red Light Therapy for Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in people over 50 in the developed world. It affects approximately 600,000 people in the UK, with that number projected to increase as the population ages. Current treatments for the “wet” form of AMD (anti-VEGF injections) are effective but invasive and ongoing. For the more common “dry” form, there has been no approved treatment — until very recently.

Photobiomodulation (PBM) for AMD is one of the most exciting areas of red light therapy research, with genuine clinical trials, a clear biological rationale, and a specific wavelength (670 nm) that has emerged as the frontrunner. This page reviews the evidence, the key researchers, and what it realistically means for people with AMD.

Understanding AMD

Dry AMD (Geographic Atrophy)

Dry AMD accounts for approximately 85–90% of AMD cases. It involves the progressive degeneration of the retinal pigment epithelium (RPE) — the supportive cell layer beneath the photoreceptors — and the accumulation of drusen (yellowish deposits of cellular debris) in the macula.

The disease progresses through stages:

Early AMD — medium-sized drusen, usually no vision symptoms
Intermediate AMD — large drusen and/or pigment changes in the RPE. Mild visual symptoms may begin
Advanced dry AMD (geographic atrophy) — areas of RPE and photoreceptor loss in the macula, causing significant central vision loss

Wet AMD (Neovascular AMD)

Wet AMD occurs when abnormal blood vessels grow beneath the retina (choroidal neovascularisation). These vessels leak fluid and blood, causing rapid central vision loss. Wet AMD accounts for 10–15% of cases but causes the majority of AMD-related blindness.

Current treatment: Anti-VEGF injections (ranibizumab, aflibercept, faricimab) are highly effective for wet AMD and are administered as regular intravitreal injections — typically monthly or every two months. These treatments stabilise or improve vision in the majority of patients.

Why AMD Is Relevant to PBM

The retina is the most metabolically active tissue in the human body per unit weight. Photoreceptors and RPE cells have extraordinarily high mitochondrial density to support their enormous energy demands. As we age, mitochondrial function in the retina declines — and this mitochondrial dysfunction is increasingly recognised as a central driver of AMD pathogenesis.

This is where PBM enters the picture: if mitochondrial decline drives retinal degeneration, and PBM enhances mitochondrial function, then PBM could theoretically slow or partially reverse the degenerative process.

The Key Research: Glen Jeffery and 670 nm Light

The most important figure in PBM for AMD research is Professor Glen Jeffery at University College London (UCL). His work has been pivotal in establishing the scientific basis for this application.

The Foundational Animal Studies

Begum et al. (2013) — Jeffery’s group demonstrated that 670 nm red light exposure reduced inflammation and improved mitochondrial function in the ageing mouse retina. The treated animals showed significantly less retinal degeneration compared with untreated controls.

Kokkinopoulos et al. (2013) — further work from the same group showed that brief daily exposures to 670 nm light (just a few minutes) improved mitochondrial membrane potential and ATP production in aged retinal cells, while reducing the accumulation of complement factor C3 — a key inflammatory marker in AMD pathology.

The Human Studies

Jeffery et al. (2021) published a landmark study in eLife demonstrating that just three minutes of 670 nm red light exposure in the morning improved colour contrast sensitivity (a measure of cone photoreceptor function) in participants aged 40 and over. Importantly, the effect was time-dependent — morning exposure was effective, but afternoon exposure was not, suggesting a link to mitochondrial circadian rhythms.

This was not an AMD treatment study per se, but it demonstrated that brief 670 nm light exposure could measurably improve retinal function in the ageing human eye.

The LIGHTSITE Trials

The most significant clinical evidence for PBM in AMD comes from the LIGHTSITE series of trials, conducted by multiple research groups:

LIGHTSITE I

Merry et al. (2017) published results from a pilot study (LIGHTSITE I) examining PBM for dry AMD. The device used was the Valeda Light Delivery System (LumiThera), which delivers 590 nm (yellow), 670 nm (red), and 850 nm (NIR) wavelengths simultaneously to the retina.

Thirty patients with dry AMD received PBM treatments (nine sessions over three weeks) and were followed for 12 months. The treatment group showed:

Improved best-corrected visual acuity (BCVA) — a gain of approximately 4 ETDRS letters at month 12
Reduced drusen volume (measured by OCT imaging)
Improved contrast sensitivity

LIGHTSITE II

Markowitz et al. (2020) published LIGHTSITE II, a larger multicentre, randomised, sham-controlled trial of the same Valeda system for intermediate dry AMD. Results at 13 months showed statistically significant improvements in the treated group compared with sham:

BCVA improvement of 4.0 letters (treated) vs 0.0 letters (sham)
Significant improvement in contrast sensitivity
Reduced drusen volume and area on OCT

LIGHTSITE III

Burton et al. (2023) reported results from LIGHTSITE III, the largest trial to date. This was a multicentre, double-masked, randomised, sham-controlled study of 137 patients with intermediate dry AMD. Patients received three treatment series (each consisting of nine sessions over three weeks) at baseline, six months, and twelve months.

The primary endpoint (mean BCVA change at 13 months) showed a statistically significant benefit for the treated group, with a 3.6-letter advantage over sham. Secondary endpoints including contrast sensitivity and drusen volume also favoured the treatment group.

What the LIGHTSITE Trials Mean

The LIGHTSITE results are encouraging for several reasons:

They are randomised, sham-controlled, and double-masked — the gold standard for clinical trial design
The effect is consistent across three trials with increasing size and rigour
The biological mechanism is well-established through the animal and basic science literature
The safety profile has been excellent — no significant adverse events reported

However, important caveats:

The visual acuity improvement (3–5 letters) is modest — it is statistically significant but represents a small functional improvement
The treatment requires repeated clinic visits (nine sessions per series, multiple series per year)
The trials were funded by LumiThera, the device manufacturer, which is standard practice but should be noted
Long-term data (beyond 13 months) is still limited

Can Home Devices Help?

This is the question most readers will have, and the honest answer is: probably not in a meaningful way, but the science does not rule it out entirely.

The Challenge

Clinical PBM for AMD uses devices specifically designed to deliver precise wavelengths and doses to the retina through the pupil. The Valeda system is a carefully calibrated ophthalmic instrument. Home LED panels and masks are not designed for retinal treatment.

What Jeffery’s Research Suggests

Jeffery’s human study (2021) used a simple 670 nm LED device held near the eye for three minutes. The dose was low (approximately 8 mW/cm² at the cornea), and it still produced measurable improvements in cone function. This suggests that retinal PBM does not necessarily require expensive clinical equipment.

However, there are critical differences between improving colour contrast sensitivity in healthy ageing eyes and treating established AMD. The LIGHTSITE trials used a multi-wavelength approach (590 + 670 + 850 nm) with precise retinal targeting — it is not clear whether a simple 670 nm LED exposure would replicate these results.

Practical Considerations

If you have AMD and want to explore PBM:

Discuss it with your ophthalmologist. They should be aware of the LIGHTSITE data and can advise on whether your specific stage and type of AMD might benefit
Do not look directly into LED panels or laser devices. Even NIR wavelengths can cause retinal damage at high irradiance
If trying a home approach based on the Jeffery protocol, use a low-power 670 nm LED at a safe distance. The dose used in his study was deliberately low — approximately 8 mW/cm² at the cornea for 3 minutes (total energy density ~1.4 J/cm²). More is not better when dealing with the retina
Morning exposure appears important — Jeffery’s data suggests mitochondrial circadian rhythms affect the response
Do not discontinue anti-VEGF treatment for wet AMD. PBM research has focused on dry AMD; there is no evidence supporting PBM as a replacement for anti-VEGF injections

Current Clinical Availability

The Valeda Light Delivery System (LumiThera) has received CE marking in Europe and is available at some specialist ophthalmology clinics. It is not yet FDA-approved in the US (regulatory submission is ongoing). In the UK, access is currently limited to a small number of private ophthalmology practices.

The treatment is not available on the NHS and is unlikely to be in the near term, pending additional long-term data and health economic analysis.

Realistic Expectations

AMD Stage	PBM Potential	Evidence Level	Action
Early dry AMD (small drusen)	Unknown — not specifically studied	Very Low	Monitor with ophthalmologist
Intermediate dry AMD	Modest benefit (3–5 letter BCVA improvement)	Moderate (LIGHTSITE trials)	Discuss with ophthalmologist; clinic-based treatment available
Advanced dry AMD (geographic atrophy)	Unknown — limited data	Very Low	Unlikely to reverse established atrophy
Wet AMD	Not a substitute for anti-VEGF	Very Low	Continue standard treatment

The Honest Assessment

PBM for AMD is one of the few areas where red light therapy has progressed from mechanistic rationale through animal studies to legitimate multicentre RCTs. The LIGHTSITE trial data is real, reproducible, and encouraging. Glen Jeffery’s work at UCL has been instrumental in establishing the scientific foundation.

That said, the effects are modest. A 3–5 letter improvement in visual acuity is meaningful in a disease with no other treatment options (for dry AMD), but it is not a dramatic restoration of vision. The treatment slows decline and may modestly improve function — it does not cure AMD.

For most people with AMD, the practical path forward is:

Regular monitoring with an ophthalmologist
Standard treatment (anti-VEGF for wet AMD, nutritional supplements per the AREDS2 protocol for intermediate dry AMD)
Awareness that PBM is an emerging clinical option that may become more widely available as the evidence base grows

Home devices are not a validated substitute for clinical PBM in this context. If retinal health is your primary concern, a conversation with your ophthalmologist about the LIGHTSITE data and potential access to clinic-based treatment is more productive than purchasing a consumer LED device.

This article is for informational purposes only and does not constitute medical advice. Macular degeneration requires ongoing ophthalmic care. Never look directly into high-intensity light sources. If you experience sudden changes in vision, seek immediate medical attention.