Latest / Glaucoma, Vision & Longevity: Supplements & Science / A New Target for Protecting the Optic Nerve? Human Glaucoma Study Strengthens the Case Against Galectin-3

Transcript

A New Target for Protecting the Optic Nerve? Human Glaucoma Study Strengthens the Case Against Galectin-3 · Glaucoma, Vision & Longevity: Supplements & Science

• 0:00
  SPEAKER_00: A new target for protecting the optic nerve?
• 0:03
  SPEAKER_00: Human glaucoma study strengthens the case against golectin-3.
• 0:08
  SPEAKER_00: Introduction.
• 0:09
  SPEAKER_00: Golectin-3 inhibition is becoming one of the more credible new neuroprotective strategies in glaucoma, but it is not yet a proven treatment and it is not ready to replace intraocular pressure lowering.
• 0:20
  SPEAKER_00: The reason for the growing interest is that golectin-3 sits at the intersection of several processes implicated in glaucoma.
• 0:27
  SPEAKER_00: Microglial activation, Miller glial stress responses, astrocyte reactivity, neuroinflammation, phagocytosis and debris clearance, metabolic dysfunction, retinal ganglion cell, and optic nerve injury.
• 0:41
  SPEAKER_00: Earlier animal studies showed that genetic removal or pharmacological inhibition of golectin-3 could preserve retinal ganglion cells in their axons despite continued ocular hypertension.
• 0:52
  SPEAKER_00: A later RAT study confirmed that intravitrial TD139, a small molecule golectin-3 inhibitor, protected retinal ganglion cells without lowering intraocular pressure.
• 1:03
  SPEAKER_00: The important new development is the demonstration that golectin-3 is strongly associated with Muller glia in human glaucomatous retinas, rather than being merely a marker of activated microglia in experimental animals.
• 1:17
  SPEAKER_00: The human finding makes the target more biologically relevant to patients, but it also makes the biology more complicated.
• 1:25
  SPEAKER_00: Golectin III may be harmful in some disease-associated microglia while supporting beneficial Miller cell functions in other circumstances.
• 1:33
  SPEAKER_00: An important evidence check.
• 1:35
  SPEAKER_00: What was actually published?
• 1:37
  SPEAKER_00: As of August 17, 2026, the directly verifiable record matching the human Miller-Glia finding is an ever 2025 abstract by Anne Rombaut and colleagues titled Golectin III is Associated with Miller Cells in Glaucoma.
• 1:52
  SPEAKER_00: I could not independently verify the exact full text, August 2026, ACTA Neuropathologica Communications citation described in the prompt through the indexed records available for this review.
• 2:05
  SPEAKER_00: That distinction matters.
• 2:07
  SPEAKER_00: The abstract provides the central findings, but it does not provide all the information normally expected from a complete research article, such as the full donor characteristics, exact sample sizes, fold changes, complete statistical tables, and detailed limitations.
• 2:24
  SPEAKER_00: The conclusions below therefore separate human tissue findings that are directly reported in the abstract, animal treatment findings from peer-reviewed studies, reasonable but still unproven interpretations.
• 2:38
  SPEAKER_00: The human findings are nevertheless important because they connect the golectin-3 pathway to the cell type spans almost the entire retina and supports retinal ganglion cell metabolism and homeostasis.
• 2:50
  SPEAKER_00: What researchers found in human glaucomatous retinas, golectin-3 increased in association with glial markers.
• 2:57
  SPEAKER_00: Rombaught and colleagues examined golectin-3 staining in a rat bead model of ocular hypertension at an early time point and an early degenerative time point, donor human retinas with late-stage glaucoma, cell cultures of human myo M1 Miller glial cells.
• 3:13
  SPEAKER_00: They compared golectin-3 with EBA 1, a marker used to identify microglia and infiltrating monocyte lineage cells, glial fibrillary acidic protein, a marker expressed by reactive astrocytes and Miller glia.
• 3:26
  SPEAKER_00: In the experimental rat retinas, the volume of golectin-3 staining and its overlap with both the microglial marker and the gliofibrillary acidic protein marker increased.
• 3:37
  SPEAKER_00: In the human retinas, however, golectin-3 was more strongly associated with the glial-fibrolary acidic protein positive compartment.
• 3:46
  SPEAKER_00: This golectin-3-glial fibrolarary acidic protein association was present in both control and glaucomatous retinas, but was significantly greater in glaucoma.
• 3:56
  SPEAKER_00: The authors interpreted this as evidence of a strong Miller-glial response.
• 4:00
  SPEAKER_00: What about microglia and astrocytes?
• 4:03
  SPEAKER_00: The findings do not mean that microglia or astrocytes are irrelevant.
• 4:07
  SPEAKER_00: Previous glaucoma studies have shown microglial activation in human glaucomatous retinas and optic nerves, increased glectin-3 expression in disease-associated microglia in experimental glaucoma, increased astrocyte reactivity and golectin-3 expression in the optic nerve head.
• 4:25
  SPEAKER_00: Increased golectin-3 in human glaucomatous optic nerve head tissue and trabecular meshwork.
• 4:32
  SPEAKER_00: In the human Miller cell study, glial fibroblary acidic protein was used as a combined marker for astrocytes and Miller glia.
• 4:40
  SPEAKER_00: Therefore, glial fibrillary acidic protein staining alone cannot perfectly separate these two cell types.
• 4:47
  SPEAKER_00: Morphological localization and the author's interpretation support a major Miller-glial contribution, but the full paper should provide more definitive cell-specific confirmation using markers such as retinaldehyde binding protein 1, glutamine synthetase, cellular retinaldehyde binding protein, or other Muller cell markers.
• 5:07
  SPEAKER_00: The most important human observation.
• 5:10
  SPEAKER_00: The key observation is not simply that galactin 3 is higher in glaucoma, it is that golectin-3 appears to be redistributed toward Muller glia in human glaucoma while also being associated with microglia and astrocytes.
• 5:24
  SPEAKER_00: That is important because Muller glia extend through almost the full thickness of the retina, regulate potassium and water balance, remove excess glutamate, provide metabolic substrates to neurons, support the blood retinal barrier, respond rapidly to mechanical, metabolic, and inflammatory stress, communicate with retinal ganglion cells, microglia, blood vessels, and other retinal cells.
• 5:48
  SPEAKER_00: A dysfunctional Müller cell can therefore influence many retinal systems at once.
• 5:53
  SPEAKER_00: Why the Miller glia association matters?
• 5:55
  SPEAKER_00: Miller glia can protect retinal ganglion cells or amplify injury.
• 5:59
  SPEAKER_00: Healthy Miller glia are essential support cells.
• 6:02
  SPEAKER_00: They help maintain the environment in which retinal ganglion cells function.
• 6:06
  SPEAKER_00: In glaucoma, this support system can become disturbed.
• 6:10
  SPEAKER_00: Experimental and review literature suggests that stressed Miller glia may release adenosine triphosphate, which can activate purinergic receptors, increase inflammatory signaling, alter glutamate handling, lose efficient potassium buffering, change their metabolism, release tumor necrosis factor alpha and interleukin-6, promote microglial activation, contribute to a feed-forward inflammatory loop.
• 6:36
  SPEAKER_00: Miller glia-derived adenosine triphosphate can act directly on retinal ganglion cells or stimulate microglia to release inflammatory mediators.
• 6:44
  SPEAKER_00: This provides a possible route through which Miller glia could contribute to retinal ganglion cell dysfunction even before extensive neuronal death has occurred.
• 6:53
  SPEAKER_00: Golectin-3 could be a signaling amplifier.
• 6:57
  SPEAKER_00: Golectin-3 is a carbohydrate binding protein that can function inside cells, on cell surfaces, or in the extracellular environment.
• 7:05
  SPEAKER_00: It can influence cell adhesion, cell migration, immune activation, phagocytosis, cell survival fibrosis, cytokine signaling, receptor clustering and signaling.
• 7:17
  SPEAKER_00: In disease-associated microglia, golectin-3 is often part of a broader program involving a polypoprotein E, lysosomal activity, phagocytosis, and inflammatory remodeling.
• 7:27
  SPEAKER_00: In glaucoma models, golectin-3 appears to help maintain a microglial state that can damage retinal ganglion cells.
• 7:33
  SPEAKER_00: The Muller cell response may not be conventionally inflammatory.
• 7:38
  SPEAKER_00: One of the most interesting findings from the Rhombach group's cell culture experiments was that recombinant golectin-3 caused morphological changes in myo M1 Muller cells consistent with gliosis.
• 7:49
  SPEAKER_00: However, the molecular response was different from the response caused by a mixture of tumor necrosis factor alpha, interleukin-1 alpha, and complement component 1Q.
• 8:01
  SPEAKER_00: The inflammatory control mixture produced extensive inflammatory gene activation.
• 8:06
  SPEAKER_00: Golectin-3 caused more modest changes, including effects that appeared to reduce some inflammatory signaling and alter Miller cell homeostatic responses.
• 8:16
  SPEAKER_00: This suggests that golectin III may not simply be a conventional inflammatory trigger in Miller cells.
• 8:22
  SPEAKER_00: It may instead act as a stress response regulator, changing the behavior of Miller glia in ways that can be protective, maladaptive, or both, depending on disease stage and cellular context.
• 8:33
  SPEAKER_00: Is galactin 3 harmful, protective, or merely a marker?
• 8:37
  SPEAKER_00: The most accurate answer is potentially all three, depending on where, when, and how it is expressed.
• 8:44
  SPEAKER_00: Evidence that golectin 3 can be harmful.
• 8:46
  SPEAKER_00: In experimental glaucoma, golectin 3 is increased in activated disease-associated microglia.
• 8:52
  SPEAKER_00: Genetic deletion of the golectin-3 gene protects retinal ganglion cells.
• 8:57
  SPEAKER_00: TD139 protects retinal ganglion cells despite continued ocular hypertension.
• 9:03
  SPEAKER_00: Golectin-3 inhibition can protect optic nerve axons in mouse models.
• 9:07
  SPEAKER_00: These intervention studies support more than a simple marker role.
• 9:11
  SPEAKER_00: They indicate that at least some forms of galactin-3 signaling contribute causally to neurodegeneration.
• 9:18
  SPEAKER_00: Evidence that galactin-3 can also be protective for.
• 9:22
  SPEAKER_00: Other retinal studies show that galactin 3 helps Miller glia perform clearance phagocytosis through the MERT-K receptor pathway.
• 9:29
  SPEAKER_00: In those studies, galactin 3 deficiency worsened Miller cell activation and aggravated retinal degeneration in inherited and chemically induced retinal injury models.
• 9:40
  SPEAKER_00: This is an important warning.
• 9:42
  SPEAKER_00: Completely eliminating golectin-3 from every retinal cell may not be beneficial.
• 9:46
  SPEAKER_00: Muller glia may use galactin-3 to clear cellular debris and restrain certain forms of reactive gliosis.
• 9:53
  SPEAKER_00: A stage-specific model is most plausible.
• 9:56
  SPEAKER_00: A reasonable working model is early or moderate galactin 3 activity may support debris clearance, cellular repair, and retinal homeostasis.
• 10:06
  SPEAKER_00: Persistent or excessive golectin-3 activity in disease-associated microglia may promote harmful inflammation, phagocytic injury, and neurodegeneration.
• 10:15
  SPEAKER_00: Golectin-3 in Miller glia may reflect a mixture of protective adaptation and maladaptive gliosis.
• 10:22
  SPEAKER_00: Late-stage galactin-3 elevation may be partly a response to damage rather than its original cause.
• 10:29
  SPEAKER_00: This is why the human finding strengthens the therapeutic case, but does not yet tell us whether broad, chronic galactin-3 suppression is the correct strategy.
• 10:38
  SPEAKER_00: The ideal treatment may need to inhibit a specific golectin-3 interaction, cell type, or disease stage rather than eliminate galactin-3 everywhere.
• 10:47
  SPEAKER_00: What earlier animal studies showed.
• 10:49
  SPEAKER_00: Mouse glaucoma study, genetic and pharmacological protection.
• 10:54
  SPEAKER_00: A major study examined the Apolypoprotein E.
• 10:57
  SPEAKER_00: golectin-3 pathway in a mouse microbed model of ocular hypertension.
• 11:01
  SPEAKER_00: The researchers found that golectin-3 was strongly increased in disease-associated retinal microglia.
• 11:07
  SPEAKER_00: Genetic deletion of the golectin-3 gene protected retinal ganglion cell bodies.
• 11:12
  SPEAKER_00: Genetic deletion also protected optic nerve axons.
• 11:16
  SPEAKER_00: Intravitrial TD139 protected retinal ganglion cells.
• 11:20
  SPEAKER_00: The protection occurred while intraocular pressure remained elevated.
• 11:24
  SPEAKER_00: TD139 did not appear to be acting by lowering intraocular pressure.
• 11:29
  SPEAKER_00: TD139 was not toxic to normal retinas in the study conditions.
• 11:34
  SPEAKER_00: The mouse experiments involved intravitreal delivery of approximately 50 nanograms of TD139 per eye at two treatment time points after ocular hypertension had already been induced.
• 11:45
  SPEAKER_00: This is important because treatment began after the pressure insult rather than before it.
• 11:52
  SPEAKER_00: How much protection did TD139 provide?
• 11:55
  SPEAKER_00: The study's central result was substantial anatomical protection, including preservation of both retinal ganglion cell bodies and axons.
• 12:04
  SPEAKER_00: However, the published summaries do not give a single universally applicable percentage of protection.
• 12:10
  SPEAKER_00: The exact magnitude depends on whether the outcome is retinal ganglion cell density, total axon number, optic nerve damage grade, or another measurement.
• 12:20
  SPEAKER_00: The most defensible description is that TD139 prevented much of the loss produced by ocular hypertension, rather than producing a small statistical delay.
• 12:30
  SPEAKER_00: Rat glaucoma study, protection at peak intraocular pressure.
• 12:34
  SPEAKER_00: Rombaut and colleagues then tested TD139 in a different species and model.
• 12:39
  SPEAKER_00: Brown Norway rats received magnetic beads to produce ocular hypertension.
• 12:44
  SPEAKER_00: A single intravitreal dose of TD-139 was given three days after ocular hypertension was induced at approximately the peak of the pressure elevation.
• 12:53
  SPEAKER_00: The findings were vehicle-treated ocular hypertensive rats had a significant reduction in retinal ganglion cell density compared with normotensive controls.
• 13:03
  SPEAKER_00: TD139 treated ocular hypertensive rats did not show a statistically significant retinal ganglion cell density reduction compared with normotensive controls.
• 13:14
  SPEAKER_00: The intraocular pressure profile and pressure exposure were comparable in the vehicle and TD-139 groups.
• 13:20
  SPEAKER_00: Microglial and astrocyte abnormalities remained present despite treatment.
• 13:25
  SPEAKER_00: The study reported a significant difference between untreated ocular hypertension and normotensive controls, with P equals 0.03, whereas the TD139 treated ocular hypertensive group was not significantly different from normotensive controls, with P equals 0.656.
• 13:43
  SPEAKER_00: Thus, the strongest quantitative claim is that TD139 produced near-complete protection of the measured retinal ganglion cell density endpoint in that particular experiment, not that it provides a fixed percentage of protection in all glaucoma models.
• 13:59
  SPEAKER_00: Is this genuine intraocular pressure independent neuroprotection?
• 14:04
  SPEAKER_00: The animal data strongly support that interpretation.
• 14:07
  SPEAKER_00: In both the mouse and rat work, ocular hypertension was maintained.
• 14:11
  SPEAKER_00: TD139 did not meaningfully reduce intraocular pressure.
• 14:16
  SPEAKER_00: Retinal ganglion cell survival improved anyway.
• 14:19
  SPEAKER_00: That is the experimental definition of intraocular pressure-independent neuroprotection.
• 14:25
  SPEAKER_00: However, this does not mean that intraocular pressure has become irrelevant.
• 14:29
  SPEAKER_00: Continuing mechanical stress from elevated intraocular pressure could still damage the optic nerve over a longer period.
• 14:36
  SPEAKER_00: A golectin-3 inhibitor would most likely be used as an add-on treatment to reduce the biological consequences of pressure-related stress, while conventional therapy addresses the pressure itself.
• 14:48
  SPEAKER_00: Were retinal ganglion cell axons protected?
• 14:51
  SPEAKER_00: Mouse evidence, yes.
• 14:54
  SPEAKER_00: The mouse study assessed optic nerve axons and reported protection of retinal ganglion cell axonal projections as well as retinal ganglion cell bodies.
• 15:02
  SPEAKER_00: This is particularly meaningful because glaucoma is an optic neuropathy, not merely a disease of retinal cell bodies.
• 15:10
  SPEAKER_00: Rat evidence, not established in that study.
• 15:14
  SPEAKER_00: The 2024 RAT TD139 study focused on retinal ganglion cell density and gross glial morphology.
• 15:20
  SPEAKER_00: It did not establish axon preservation with the same level of evidence as the earlier mouse study.
• 15:26
  SPEAKER_00: Therefore, retinal ganglion cell body protection, demonstrated in mice and rats, axon protection, demonstrated in the mouse study, axon protection in rats, not yet established by the 2024 study, long-term optic nerve function, not yet established.
• 15:41
  SPEAKER_00: Was vision preserved?
• 15:43
  SPEAKER_00: This is a major limitation.
• 15:44
  SPEAKER_00: The glaucoma TD139 studies primarily measured retinal ganglion cell survival, optic nerve axon counts in the mouse study, microglial and astrocyte morphology, intraocular pressure.
• 15:56
  SPEAKER_00: They did not establish preservation of visual performance with robust behavioral or electrophysiological testing.
• 16:03
  SPEAKER_00: There is therefore an important distinction between anatomical neuroprotection, more cells and axons remain, functional neuroprotection, those cells continue to transmit useful visual information.
• 16:16
  SPEAKER_00: A treatment can preserve cell markers without fully preserving synaptic function, electrical signaling, contrast sensitivity, or visual field performance.
• 16:25
  SPEAKER_00: Future studies need pattern electroretinography, visual evoke potentials, optokinetic behavior, contrast and optical coherence tomography, and longitudinal visual field-like testing in appropriate animals.
• 16:38
  SPEAKER_00: Why the human finding strengthens the translational case?
• 16:42
  SPEAKER_00: The human Miller-Glia result adds three important pieces to the existing animal evidence.
• 16:47
  SPEAKER_00: The target is present at the site of human disease.
• 16:51
  SPEAKER_00: A target that works only in a mouse microglial state may fail in human glaucoma.
• 16:56
  SPEAKER_00: Demonstrating abnormal galactin-3 distribution in human glaucomatous retinas reduces that concern.
• 17:03
  SPEAKER_00: The relevant cell network may be broader than microglia.
• 17:06
  SPEAKER_00: The discovery points toward a network involving millerglia, microglia, astrocytes, retinal ganglion cells, the optic nerve head.
• 17:15
  SPEAKER_00: A treatment directed at galactin-3 could therefore influence communication among several cell populations rather than targeting only one immune cell type.
• 17:23
  SPEAKER_00: The mechanism may be relevant to late disease.
• 17:27
  SPEAKER_00: The human donor eyes represented late glaucoma, while the animal work demonstrated benefit during earlier and intermediate stages.
• 17:35
  SPEAKER_00: Together, the findings suggest that golectin-3 biology may persist across disease progression.
• 17:41
  SPEAKER_00: The important caveat is that late-stage human tissue cannot determine whether golectin 3 initiated the disease, accelerated it, or responded to preexisting injury.
• 17:51
  SPEAKER_00: Has TD139 been tested in humans?
• 17:54
  SPEAKER_00: Yes, but not in glaucoma.
• 17:56
  SPEAKER_00: Inhaled TD139, also known as GB0139-TD139, was tested by inhalation in healthy volunteers and patients with idiopathic pulmonary fibrosis.
• 18:08
  SPEAKER_00: In the phase one half A study, 36 healthy subjects and 24 patients with idiopathic pulmonary fibrosis participated.
• 18:16
  SPEAKER_00: Healthy volunteers received single doses up to 50 milligrams.
• 18:20
  SPEAKER_00: Patients received once daily treatment for 14 days at doses up to 10 milligrams.
• 18:25
  SPEAKER_00: The treatment was generally well tolerated.
• 18:28
  SPEAKER_00: Mild taste disturbance was the most frequent treatment-emergent adverse event in healthy volunteers.
• 18:34
  SPEAKER_00: Cough occurred in a minority of participants.
• 18:37
  SPEAKER_00: No major treatment-related laboratory, electrocardiographic, or vital sign safety signal was identified.
• 18:44
  SPEAKER_00: One patient experienced a serious pulmonary event after treatment, but the investigators considered it related to pneumonia and the bronchoalveolar lavage procedure rather than directly to TD139.
• 18:56
  SPEAKER_00: This history is reassuring but does not establish the safety of repeated intravitreal or topical retinal exposure.
• 19:03
  SPEAKER_00: A larger phase 2B pulmonary fibrosis study of GB0139, formerly known as TD139, enrolled 172 participants and has been listed as completed.
• 19:14
  SPEAKER_00: Its existence provides additional clinical development experience, but pulmonary safety data cannot automatically be transferred to ophthalmic use.
• 19:23
  SPEAKER_00: Other golectin-3 inhibitors.
• 19:26
  SPEAKER_00: Other golectin-3 inhibitors have also entered human studies.
• 19:29
  SPEAKER_00: GB1211, an oral galactin-3 inhibitor, was tested in a phase 1 study involving 78 healthy participants.
• 19:37
  SPEAKER_00: No major safety concerns were identified, although gastrointestinal symptoms, headache, rash, and other mild events occurred.
• 19:46
  SPEAKER_00: Selvigaltin, another name used for GB1211, was well tolerated in a small tablet formulation study.
• 19:53
  SPEAKER_00: GRMDZO2, a different galactin-3 inhibitor, was reported as safe and well-tolerated in an early study of patients with advanced liver fibrosis.
• 20:03
  SPEAKER_00: These studies show that galactin-3 can be pharmacologically modulated in humans.
• 20:07
  SPEAKER_00: They do not establish that long-term suppression is safe for the retina, optic nerve, immune system, or central nervous system.
• 20:16
  SPEAKER_00: How could a golectin-3 inhibitor be delivered?
• 20:19
  SPEAKER_00: Intravitrial injection.
• 20:21
  SPEAKER_00: Intravitrial delivery is the most immediately plausible route for a retinal neuroprotective drug because it places the compound close to retinal ganglion cells, mular glia, microglia, and the inner retina.
• 20:33
  SPEAKER_00: Advantages include direct retinal exposure, potentially low systemic exposure, ability to use a small dose, compatibility with existing injection-based retinal treatments.
• 20:43
  SPEAKER_00: Disadvantages include repeated eye injections, risk of infection, bleeding, inflammation, and retinal injury, patient burden, unknown duration of TD139 activity in the human eye, need for a clinically acceptable solvent and formulation.
• 20:58
  SPEAKER_00: The animal studies used small intravitreal doses, but an effective and safe human dose has not been established.
• 21:05
  SPEAKER_00: Sustained release or subconjunctival delivery.
• 21:08
  SPEAKER_00: A 2025 research abstract reported that both a slow release subconjunctival gel and eyedrops containing TD139 or N-acetyldelactosamine protected retinal ganglion cells in a mouse microbead model.
• 21:22
  SPEAKER_00: The subconjunctival gel was injected once, while the eyedrops were given twice daily for 20 days.
• 21:28
  SPEAKER_00: This is promising because it suggests that repeated intravitrial injections may not be necessary.
• 21:34
  SPEAKER_00: However, the results were presented as an abstract and the work did not establish human retinal exposure, long term safety, axon protection, preservation of visual function, the concentration reaching Miller glia or the optic nerve head.
• 21:49
  SPEAKER_00: Topical eye drops.
• 21:51
  SPEAKER_00: Topical therapy would be attractive because it is familiar and non invasive.
• 21:55
  SPEAKER_00: The main obstacle is delivery.
• 21:57
  SPEAKER_00: The cornea, conjunctiva, sclera, Lera, vitreus, and inner limiting membrane all limit how much drug reaches the posterior retina.
• 22:06
  SPEAKER_00: Mouse eyedrop results are encouraging, but do not prove that a clinically practical human eyedrop can deliver enough galactin-3 inhibitor to the retina.
• 22:15
  SPEAKER_00: Topical therapy may become more realistic with nanoparticles, mucoadhesive formulations, subconjunctival depots, transport-enhancing prodrugs, formulations designed to cross the sclera and vitreous.
• 22:28
  SPEAKER_00: Systemic therapy.
• 22:29
  SPEAKER_00: Oral galactin-3 inhibitors already have human pharmacokinetic data.
• 22:33
  SPEAKER_00: Systemic therapy could theoretically treat both eyes and avoid ocular procedures.
• 22:38
  SPEAKER_00: The disadvantages are substantial.
• 22:40
  SPEAKER_00: Much greater exposure of immune cells throughout the body.
• 22:43
  SPEAKER_00: Potential interaction with normal macrophage and repair functions.
• 22:47
  SPEAKER_00: Greater risk of drug interactions.
• 22:49
  SPEAKER_00: Uncertain delivery into the retina and optic nerve.
• 22:52
  SPEAKER_00: Need for chronic dosing over many years.
• 22:56
  SPEAKER_00: For glaucoma, local ocular treatment is likely to be preferable unless systemic exposure proves necessary to reach the optic nerve head or central visual pathways.
• 23:06
  SPEAKER_00: Potential problems with chronic golectin-3 suppression.
• 23:09
  SPEAKER_00: Golectin-3 is not simply a harmful inflammatory molecule.
• 23:13
  SPEAKER_00: It participates in normal, immune surveillance, cell adhesion, phagocytosis, tissue repair, cellular growth and differentiation, clearance of damaged material, fibrosis, and wound healing.
• 23:24
  SPEAKER_00: The Miller cell phagocytosis research is especially relevant.
• 23:28
  SPEAKER_00: Eliminating golectin 3 worsened Miller cell activation and retinal degeneration in some non-glaucoma models.
• 23:35
  SPEAKER_00: This suggests that chronic, complete suppression could interfere with beneficial debris clearance.
• 23:41
  SPEAKER_00: Potential risks include impaired removal of damaged cellular material, altered retinal immune privilege, increased susceptibility to infection, abnormal wound healing, unwanted effects on retinal blood vessels, disruption of Muller cell homeostasis, effects on microglial repair and resolution responses.
• 24:01
  SPEAKER_00: Different responses in early versus late glaucoma.
• 24:04
  SPEAKER_00: The safest strategy may be partial, local, time-limited, or cell-selective inhibition rather than permanent whole-body galactin-3 deletion.
• 24:12
  SPEAKER_00: How galactin-3 inhibition compares with other neuroprotective strategies.
• 24:17
  SPEAKER_00: For the full table, please open this article on VisualFieldTest.com.
• 24:22
  SPEAKER_00: Nicotinamide has the greatest clinical maturity among metabolic strategies.
• 24:27
  SPEAKER_00: A randomized trial of nicotinamide and pyruvate was designed to continue standard intraocular pressure treatment while measuring structural and functional outcomes.
• 24:36
  SPEAKER_00: However, systematic reviews have concluded that current human evidence remains limited and not yet sufficient to prove preservation of visual field mean deviation.
• 24:47
  SPEAKER_00: Golectin-3 inhibition is less clinically advanced than nicotinamide, but it has a distinctive advantage.
• 24:53
  SPEAKER_00: It targets a cell extrinsic glial and inflammatory pathway that may remain active even when retinal ganglion cell metabolism is already compromised.
• 25:03
  SPEAKER_00: What must happen before a human glaucoma trial?
• 25:06
  SPEAKER_00: Several experiments should be completed first.
• 25:08
  SPEAKER_00: Publish and independently replicate the human tissue findings.
• 25:12
  SPEAKER_00: The human study should provide donor numbers and clinical histories, glaucoma subtype and severity, intraocular pressure history, medication history, exact galactin-3 measurements, cell-specific markers for Millerglia, microglia, and astrocytes.
• 25:28
  SPEAKER_00: Analysis of early, moderate, and late disease.
• 25:31
  SPEAKER_00: A larger, independent human cohort is essential.
• 25:34
  SPEAKER_00: Separate the roles of different retinal cells.
• 25:37
  SPEAKER_00: Researchers should use cell-specific genetic or pharmacological approaches to determine whether protection comes mainly from inhibiting golectin-3 in microglia, millarglia, astrocytes, infiltrating macrophages, the optic nerve head.
• 25:52
  SPEAKER_00: The treatment might be beneficial in microglia, but harmful if it suppresses a protective Miller cell pathway.
• 25:58
  SPEAKER_00: Demonstrate visual function preservation.
• 26:01
  SPEAKER_00: Future animal studies should measure.
• 26:03
  SPEAKER_00: Pattern electroretinography, visual evoked potentials, optokinetic behavior, contrast sensitivity, synaptic integrity, retinal ganglion cell dendrites, optic nerve axons, optical coherence tomography measures over time.
• 26:18
  SPEAKER_00: Cell counts alone are not enough to justify a human neuroprotection trial.
• 26:22
  SPEAKER_00: Test chronic and clinically realistic disease models.
• 26:25
  SPEAKER_00: TD139 should be studied in aged animals, both sexes, chronic ocular hypertension, normal tension glaucoma models, models with controlled intraocular pressure but continued progression, non-human primates, animals receiving standard intraocular pressure treatment.
• 26:42
  SPEAKER_00: Establish ocular pharmokinetics and toxicology.
• 26:45
  SPEAKER_00: Researchers need to know how long TD19 remains in the vitreous, whether it reaches Miller glia and the optic nerve head, whether it reaches the central nervous system, the minimum effective dose, whether repeated dosing causes inflammation or retinal toxicity, whether a sustained release formulation is superior to repeated injections.
• 27:06
  SPEAKER_00: Identify a biomarker for patient selection.
• 27:09
  SPEAKER_00: Golectin III in aqueous humor is elevated in patients with glaucoma, but one study found that it was more closely associated with historical maximum intraocular pressure than with standard measures of current glaucoma severity.
• 27:22
  SPEAKER_00: This suggests golectin 3 may reflect prior injury or inflammatory burden rather than simply tracking visual field loss.
• 27:30
  SPEAKER_00: A future trial might select patients based on elevated aqueous humor golectin-3, progressive retinal nerve fiber layer thinning, continued progression despite controlled intraocular pressure, evidence of inflammatory or glial activation, specific genetic or metabolic profiles are golectin-3 inhibitor glaucoma trials planned or registered.
• 27:52
  SPEAKER_00: As of August 17, 2026, I found no publicly registered clinical trial testing TD139, GB 1211, Selvigaltin, GRMD02, or another golectin-3 inhibitor specifically for glaucoma.
• 28:07
  SPEAKER_00: The registered human studies I could verify involve pulmonary fibrosis, healthy volunteers, liver disease, and cancer-related indications rather than glaucoma.
• 28:17
  SPEAKER_00: There is, however, clear translational activity from the Karolinska Institutit and St.
• 28:22
  SPEAKER_00: Eric Eye Hospital Group.
• 28:24
  SPEAKER_00: A 2026 research project specifically describes the goal of defining how golectin-3 links neuroinflammation and metabolic dysfunction and preparing golectin-3 inhibitors for possible glaucoma translation.
• 28:38
  SPEAKER_00: That is a development program, not evidence that a glaucoma clinical trial has begun.
• 28:43
  SPEAKER_00: Conclusion.
• 28:44
  SPEAKER_00: Has the confirmation of golectin-3 abnormalities in human glaucoma identified one of the strongest new drug targets for protecting retinal ganglion cells independently of eye pressure?
• 28:55
  SPEAKER_00: It has identified one of the strongest new preclinical targets, but not yet one of the strongest clinically validated treatments.
• 29:03
  SPEAKER_00: The case for galactin-3 inhibition is unusually compelling because golectin 3 is abnormal in human glaucomatous tissue.
• 29:12
  SPEAKER_00: The human signal is strongly associated with Miller glia.
• 29:15
  SPEAKER_00: Golectin-3 is also linked to disease-associated microglia and reactive astrocytes.
• 29:21
  SPEAKER_00: Genetic deletion protects retinal ganglion cells and axons in mice.
• 29:25
  SPEAKER_00: TD139 protects retinal ganglion cells in mice and rats.
• 29:30
  SPEAKER_00: Protection occurs despite continued elevated intraocular pressure.
• 29:34
  SPEAKER_00: TD-139 has already been administered to humans for non-ocular diseases with generally acceptable short-term safety.
• 29:41
  SPEAKER_00: But important gaps remain.
• 29:43
  SPEAKER_00: Human glaucoma tissue evidence is currently limited, and based on the directly verifiable record, available mainly as a conference abstract.
• 29:51
  SPEAKER_00: No study has yet shown preservation of visual function with TD139 in glaucoma.
• 29:56
  SPEAKER_00: Long-term ocular safety is unknown.
• 29:59
  SPEAKER_00: Golectin-3 has beneficial functions in Miller cell phagocytosis and retinal repair.
• 30:04
  SPEAKER_00: The best target may be a specific galactin-3 interaction or cell type rather than golectin-3 globally.
• 30:11
  SPEAKER_00: No galactin-3 inhibitor glaucoma clinical trial is publicly registered as of August 17, 2026.
• 30:19
  SPEAKER_00: The most realistic future role is therefore adjunctive neuroprotection.
• 30:24
  SPEAKER_00: Golectin-3 inhibition used alongside intraocular pressure lowering to protect retinal ganglion cells from the inflammatory and metabolic consequences of glaucoma.
• 30:33
  SPEAKER_00: The human Miller-Glia finding makes that strategy more credible, but the next decisive step will be proving that treatment preserves axons, electrical signaling, and vision, not only retinal ganglion cell markers.
• 30:47
  SPEAKER_00: All links to sources are available in the text version of this article.
• 30:51
  SPEAKER_00: You can find the full article at VisualFieldTest.com.
• 30:55
  SPEAKER_00: Thanks for listening.
• 30:56
  SPEAKER_00: To check your visual field, click the link at the bottom of this article or visit visualfieldtest.com.