Photobiomodulation in Ophthalmology: Mechanisms and Clinical Evidence
Photobiomodulation, or PBM, uses low-level red and near-infrared light to influence cellular energy production. In ophthalmology, it's being studied most seriously for retinal conditions like dry age-related macular degeneration, where mitochondrial stress in the retina and RPE plays a central role. In this episode, Dr. Saikumar Gandapodi walks through the biology — how light interacts with cytochrome c oxidase, why the retina is uniquely metabolically demanding, and what recent human trials do and don't tell us.
We separate the established from the emerging at every turn. Dr. Gandapodi is candid about the limits: PBM is not a cure, dosing is still being worked out, and much of the mechanistic story comes from lab and animal models. He also explains how PBM fits into an integrative, whole-person framework at Netra Eye Institute — always as an adjunct to standard ophthalmic care, never a replacement.
This is a research-driven conversation for anyone curious about where light-based therapy is genuinely heading in eye medicine, and how to think critically about early but promising science.
Transcript
[on-hold music] Welcome to the Netra Eye Institute Podcast,
Speaker:where modern vision science meets the wisdom of integrative ophthalmology.
Speaker:Today, we are joined by Dr. Saikumar Gandapodi,
Speaker:founder and director of Netra Eye Institute,
Speaker:whose work is dedicated to redefining how patients understand and approach chronic
Speaker:and degenerative eye conditions.
Speaker:His goal is simple:
Speaker:to help patients, families, and clinicians explore a more comprehensive and
Speaker:integrative approach to long-term eye health.
Speaker:This is the Netra Eye Institute Podcast. Let's begin.
Speaker:Welcome back to the show. I'm here with Dr. Saikumar Gandapodi, board-certified
Speaker:doctor of Oriental medicine, a practitioner of Ayurvedic medicine, and
Speaker:the founder and director of Netra Eye Institute, a holistic eye care center.
Speaker:Today, we're getting into photobiomodulation, light-based therapy in
Speaker:ophthalmology. Dr. Gandapodi, thanks for being here.
Speaker:Thanks for having me. This is one of my favorite topics right now because the
Speaker:science is genuinely moving, but it also needs careful handling, so let's keep it
Speaker:-honest. -Let's start simple. What is
Speaker:photobiomodulation?
Speaker:At its core, it’s using low levels of red and near-infrared light to nudge cells
Speaker:toward better function. Not heat, not surgery, just specific wavelengths of
Speaker:light delivered at low power. The idea is that certain cells absorb that light and
Speaker:respond by making energy more efficiently.
Speaker:So how does a cell actually absorb light in a useful way? What's the mechanism?
Speaker:The leading explanation involves an enzyme in the mitochondria called cytochrome c
Speaker:oxidase. It’s part of the electron transport chain, the machinery that makes
Speaker:ATP, your cellular fuel. Red and near-infrared light appear to be absorbed
Speaker:by that enzyme, and that can improve how efficiently the mitochondria produce
Speaker:-energy. -And why would the eye specifically care
Speaker:-about mitochondrial energy? -Because the retina is one of the most
Speaker:energy-hungry tissues in the body. Photoreceptors are packed with
Speaker:mitochondria. Vision is metabolically expensive. When those mitochondria start
Speaker:to struggle, the retina is very vulnerable, so a therapy aimed at
Speaker:mitochondrial efficiency has an obvious rationale here.
Speaker:Which condition does that rationale fit best?
Speaker:Dry age-related macular degeneration is where most of the serious interest sits.
Speaker:In dry AMD, the retinal pigment epithelium, the support layer under the
Speaker:photoreceptors, accumulates stress over time.
Speaker:There’s oxidative damage, mitochondrial dysfunction, and low-grade inflammation.
Speaker:PBM is being studied as a way to support those cells’ energy metabolism.
Speaker:Let’s be precise about the evidence.
Speaker:What do we actually have in humans for dry AMD?
Speaker:The most notable is the LightSight program, a series of clinical trials,
Speaker:including LightSight 3, that studied a specific multi-wavelength PBM device in
Speaker:dry AMD.
Speaker:Those trials reported some improvement in visual acuity in treated eyes versus sham
Speaker:over the study period.
Speaker:That’s real, published human data, and it’s encouraging.
Speaker:But you’re hedging.
Speaker:Why?
Speaker:Because we should be careful about how far we push it.
Speaker:These are relatively modest effects in selected patients over defined timeframes.
Speaker:It doesn’t reverse advanced disease, and long-term durability is still being worked
Speaker:out.
Speaker:It’s promising, not settled.
Speaker:I’d call PBM in dry AMD emerging clinical evidence, not established standard of
Speaker:care.
Speaker:What about the lab and animal side?
Speaker:Is the mechanism well supported there?
Speaker:The preclinical story is stronger and older.
Speaker:In laboratory and animal models, near-infrared light has been shown to
Speaker:reduce retinal oxidative stress,
Speaker:dampen inflammatory markers, and preserve mitochondrial function after various
Speaker:insults.
Speaker:Some of that work goes back years.
Speaker:But animal retinas aren’t human retinas, so we hold those results as supportive,
Speaker:not conclusive.
Speaker:Beyond ATP, are there other pathways people talk about?
Speaker:A few, and I'd flag them as mechanistically plausible but less nailed
Speaker:down.
Speaker:One is a brief controlled rise in signaling molecules, reactive oxygen
Speaker:species, and nitric oxide that may actually improve local blood flow and
Speaker:trigger protective cellular responses.
Speaker:Another is modulation of inflammatory cytokines.
Speaker:In the retina and RPE, calming chronic low-grade inflammation is a reasonable
Speaker:target.
Speaker:You mentioned blood flow.
Speaker:How relevant is ocular circulation to this?
Speaker:It’s part of the picture. The outer retina depends heavily on the choroidal blood
Speaker:supply, and impaired perfusion contributes to stress in AMD.
Speaker:If PBM helps local nitric oxide signaling and vascular tone,
Speaker:better delivery of oxygen and nutrients could matter.
Speaker:But I want to be clear, the blood flow angle is still more hypothesis than proven
Speaker:-human outcome. -Are there ophthalmic conditions where PBM
Speaker:-is being explored beyond AMD? -There’s early interest in diabetic retinal
Speaker:disease, some in Stargardt type dystrophies, and preliminary work on the
Speaker:ocular surface,
Speaker:dry eye, and meibomian gland dysfunction using light-based devices.
Speaker:I'd put dry AMD as the most developed, dry eye as an active but earlier area, and
Speaker:the rest as genuinely preliminary.
Speaker:I don't want to oversell any of them.
Speaker:That's a good discipline.
Speaker:Let's talk about dosing, because with light, I imagine more isn't always better.
Speaker:Exactly right.
Speaker:PBM follows what's called a biphasic dose response.
Speaker:Too little does nothing. The right window helps. Too much can actually suppress the
Speaker:benefit.
Speaker:Wavelength, power, duration, and treatment frequency all matter.
Speaker:And that's honestly one of the field's biggest challenges,
Speaker:standardizing protocols so results are reproducible.
Speaker:Is that why results across studies can look inconsistent?
Speaker:A lot of it, yes. Different devices, different wavelengths, different dosing.
Speaker:You can't directly compare them. That's a scientific limitation, not a reason for
Speaker:hype or dismissal.
Speaker:It means we need well-designed sham control trials with clearly reported
Speaker:-parameters before making strong claims. -How does conventional ophthalmology view
Speaker:this today? Fairly stated.
Speaker:Fairly stated, conventional care is appropriately cautious and
Speaker:evidence-driven.
Speaker:For dry AMD, the mainstays remain things like the AREDS2 nutritional formulation,
Speaker:and for geographic atrophy, newer complement inhibitor injections that have
Speaker:real regulatory approval.
Speaker:PBM is in first line. Where I see opportunity is as a complementary tool
Speaker:that targets mitochondrial and oxidative stress, which conventional options don't
Speaker:fully address.
Speaker:That leads naturally to your work.
Speaker:Tell us about Netra Restoration Therapy and where PBM fits.
Speaker:Netra Restoration Therapy, or NRT, is our full-spectrum integrative approach.
Speaker:The philosophy is that chronic retinal disease is multifactorial.
Speaker:Energy metabolism, oxidative stress, inflammation, blood flow, and whole body
Speaker:factors all interact.
Speaker:So instead of a single lever, we try to support several pathways at once, always
Speaker:alongside standard ophthalmic care, never instead of it.
Speaker:And PBM is one of those levers?
Speaker:It can be, when appropriate, as the mitochondrial and energy support piece.
Speaker:Around it, we look at nutrition, oxidative stress reduction, systemic inflammation,
Speaker:even metabolic and vascular health. No guarantees, no cure claims. It's an
Speaker:adjunct framework, and I tell every patient the evidence is still evolving.
Speaker:You come from Oriental and Ayurvedic medicine.
Speaker:How do those frameworks connect to something as modern as light therapy?
Speaker:I use them as interpretive parallels, not scientific equivalents. That distinction
Speaker:matters.
Speaker:In Ayurveda, tissue nourishment and the concept of ojas, roughly a kind of vital
Speaker:reserve, map loosely onto ideas like cellular resilience and mitochondrial
Speaker:reserve.
Speaker:In Chinese medicine, blood stasis loosely parallels impaired perfusion.
Speaker:These are conceptual bridges that help me think about the whole person,
Speaker:not proof of a mechanism.
Speaker:And herbal formulas,
Speaker:-do those play a role here, evidence-wise? -They're interesting because a single
Speaker:formula contains many phytochemicals hitting multiple targets:
Speaker:antioxidant, anti-inflammatory, vascular. Modern network pharmacology studies that
Speaker:as multi-component, multi-target action.
Speaker:Some botanicals used for eye health have lab and early clinical data,
Speaker:but I'm careful. Much of it is preliminary, and quality and
Speaker:standardization vary.
Speaker:I never present them as established retinal treatments.
Speaker:If a listener has dry AMD and is curious about PBM,
Speaker:what's your honest guidance?
Speaker:First, stay under the care of your ophthalmologist. That's non-negotiable.
Speaker:Second, understand PBM is an emerging adjunct with encouraging but modest human
Speaker:data, not a cure.
Speaker:Third, if you pursue it, do it through someone using studied protocols and
Speaker:tracking your vision objectively. Curiosity is great. Informed curiosity is
Speaker:-better. -What would move this from promising to
Speaker:established for you?
Speaker:Larger, longer, well-controlled trials with standardized dosing, clear anatomical
Speaker:and functional endpoints, and durability data over years,
Speaker:and ideally biomarkers that show the mitochondrial effect is really happening
Speaker:in the human retina.
Speaker:If those line up, PBM earns a firmer place.
Speaker:We're not there yet, but the trajectory is real.
Speaker:Any safety concerns people should know about?
Speaker:In the studied ophthalmic devices and doses, PBM has generally shown a good
Speaker:safety profile.
Speaker:That's one of its attractions.
Speaker:But the eye is sensitive and light parameters matter,
Speaker:so this shouldn't be a random home gadget aimed at the retina.
Speaker:Proper devices, proper dosing, proper supervision.
Speaker:That's the responsible way to explore it.
Speaker:Last question.
Speaker:What's the single takeaway you want people to hold on to?
Speaker:That light-based therapy targeting retinal mitochondria is one of the more
Speaker:scientifically grounded emerging tools in eye care.
Speaker:Real mechanism,
Speaker:early human data, honest limitations.
Speaker:Treat it as a complement to excellent standard care, not a shortcut around it.
Speaker:And keep watching the trials, because this space is going to keep evolving.
Speaker:Dr. Gandapodi,
Speaker:this was clear, balanced,
Speaker:and genuinely useful.
Speaker:Thank you.
Speaker:My pleasure. Thanks for keeping it rigorous.
