Findings from a recent review published in the Journal of Ocular Pharmacology and Therapeutics present a new translation of ancient Egyptian eye remedies and evaluate whether human milk could serve as a low-cost biological treatment for dry eye disease (DED).
Give me some background first.
DED is one of the most common ophthalmic conditions, with prevalence estimates ranging from 5% to 17% across population-based studies.
- Standard management starts with lubricants and eyelid hygiene, then escalates to prescription therapies and/or in office treatments and, for patients who don't respond, autologous serum tears.
The issue: Autologous serum tears are expensive.
- In the UK, the National Health Service Blood and Transplant (NHSBT) provides a 3-to-5-month supply for approximately £1,100.
- And in the U.S, insurance coverage is inconsistent, and patients often pay out of pocket.
That cost barrier has pushed researchers to look for cheaper biological alternatives.
Now, talk about the study.
A team of UK-based ophthalmologists examined four ophthalmic remedies in the Ebers Papyrus, an ancient medical text considered the most comprehensive surviving document from ancient Egypt.
All four remedies call for human milk applied to the eyes for conditions including "blood in the eyes," "red inflammation in the eyes," and "opening the vision."
Some context: These remedies all specify milk from a woman who has born a son. Egyptologists have traditionally read this as a reference to the goddess Isis, whose milk is said to have sustained her son Horus and restored her dead husband Osiris. But the review authors propose the specification may have had a more literal, biological basis.
- From there, the review traces the transmission of these remedies through Greek, Roman, and Byzantine medical literature before pivoting to modern biomedical evidence.
Who was included in the study?
As this was a narrative review—not a clinical trial—the authors searched PubMed using the terms "eye" and "milk" or "colostrum”.
Of 969 search results, nine peer-reviewed studies met their inclusion criteria: original research involving topical milk or milk-derived products for any ophthalmic condition in human or animal subjects.
The included studies covered:
- Mouse models of corneal injury and DED
- Randomized controlled trials (RCTs) of colostrum for neonatal conjunctivitis prevention
- Investigations of milk-derived compounds (oligosaccharides and exosomes)
Findings?
The biological overlap between human milk and autologous serum tears is the core of the argument.
Human milk contains epidermal growth factor (EGF), transforming growth factor alpha (TGF-α), and insulin-like growth factor 1 (IGF-1), the same growth factors believed to give serum tears their therapeutic effect on the ocular surface.
- Case in point: EGF concentrations in colostrum reach 100 to 400 ng/mL, compared to just 0.7 ng/mL in human serum and 2 ng/mL in basal tears.
Animal data backs this up. In a mouse model of DED induced by benzalkonium chloride, human milk reversed the epithelial thinning caused by the chemical exposure and reduced fluorescein staining scores with QID dosing over four days of treatment.
Go on ...
A separate study directly compared human milk to 50% mouse autologous serum in a corneal epithelial defect model.
- The milk group healed faster, with significantly better fluorescein scores (P < 0.05).
A third mouse study also confirmed faster re-epithelization with milk at 8 hours post-injury (P < 0.03) , finding higher levels of Ki67-positive cells, a marker of cellular proliferation.
Tell me more.
A milk oligosaccharide called 2-fucosyl-lactose reversed atropine-induced DED in rabbits in a dose-dependent manner.
- Tear break-up time (TBUT) values reached 8.75 seconds at the 0.01% dose and 34.5 seconds at the 1% dose, with tear volume also increasing.
Bovine milk exosomes are also in the mix. When loaded with dexamethasone via ultrasound, they produced faster corneal healing after alkaline injury in mice than free dexamethasone alone.
Even unloaded, the exosomes increased corneal epithelial cell vitality and migration rate.
And on the clinical side?
An RCT of 300 preterm neonates found that topical colostrum reduced conjunctivitis incidence compared to no treatment (P < 0.03), though erythromycin still performed best.
A separate RCT found human milk non-inferior to sodium azulene sulfonate for treating eye discharge in infants.
Limitations?
The big one: No human study has tested topical human milk for DED. All the DED-specific evidence comes from animal models.
- The clinical trials that do exist focused on neonatal conjunctivitis, a different condition entirely.
Other considerations:
- This was a narrative synthesis, not a systematic review or meta-analysis
- The nine studies were too heterogeneous in design for pooled analysis
- Translational hurdles were also substantial
- Any ophthalmic milk product would need sterile processing, standardized osmolarity and pH, and cold-chain distribution
- An ethical dimension: Donor human milk supply may already be insufficient for its primary purpose of feeding premature infants, so diverting it for ophthalmic use raises allocation concerns
Expert opinion?
The authors made a clear case for bovine colostrum as the more practical path forward. As a byproduct of the dairy industry, raw bovine colostrum can retail for as little as around $13 per liter, a fraction of what autologous serum tears cost.
But they also acknowledged that no pharmaceutical-grade ophthalmic colostrum product currently exists, and bioactive properties vary considerably across commercially available brands.
- Their position: While human milk and bovine colostrum both warrant investigation as biological tear substitutes, any clinical application should remain confined to experimental settings until human studies are conducted.
Anything else?
The sex-specific differences in human milk composition add an interesting wrinkle.
Why: A proteomic analysis of 98 human milk samples found sex-specific differences for 42 of 146 proteins analyzed, with milk produced for male infants containing more proteins involved in energy metabolism.
Male-infant-directed milk also carries approximately 25% higher caloric content.
Whether those compositional differences matter for topical ophthalmic use is unknown. But they do align, at least loosely, with the ancient Egyptian specification of milk from a woman who bore a son.
Take home.
No one's prescribing breast milk eye drops yet.
But this review makes a reasonable case that the biology is there, and the price point for bovine colostrum could make it a viable option for patients who can't access or afford autologous serum tears.
Human trials are the obvious next step.