Is Thicker Eye Discharge Normal After Using PRP (Platelet-Rich Plasma) Eye Drops?

This post is educational and not a substitute for individual medical advice. When in doubt, contact the clinician who prescribed your PRP drops or your eyeMD. 

If you have started platelet-rich plasma (PRP) eye drops for dry eye or another ocular surface condition and you may have noticed thicker discharge, which is most often normal. And in the world literature there are still no reported cases of corneal infection using PRP eye drops (please see below).*

Thus, in the vast majority of cases a small amount of extra mucus or crusting is minor and settles on its own. 

Because certain types of discharge can also be the first sign of an eye infection, it is important to know the color— so it is worth knowing which features are reassuring and which mean you should be seen. This post walks through both.

What PRP eye drops are

PRP eye drops are made from a small sample of your own blood, spun down to concentrate the platelets and the growth factors they contain. Because the drops come from your own blood, they closely resemble your natural tears and are used to help the eye surface heal in conditions such as severe dry eye, Sjögren's-related dry eye, graft-versus-host disease, and non-healing corneal surface problems. Being autologous (from you), they carry a very low risk of allergic or transmissible reactions.

How well tolerated PRP eye drops usually are

In clinical studies, PRP and closely related blood-derived drops have generally been very well tolerated. In a large multicenter report of plasma-rich-in-growth-factors eye drops, only about 1% of patients reported any side effect, and that was a mild burning sensation. Pilot and comparative studies of PRP drops similarly reported no significant adverse effects. So serious problems are uncommon — but "uncommon" is not "never," which is why new discharge is worth paying attention to.

Why a little extra discharge can happen

Some minor discharge, watering, or crusting in the lashes can occur simply from:

- Having a very dry, irritated ocular surface to begin with (the reason the drops were prescribed)

- Mild transient irritation or burning from the drop itself

- Normal mucus that collects overnight and mattes the lashes

Blood-derived drops like these are, on rare occasion, associated with mild irritation or an episode of conjunctivitis, so a change in discharge is worth watching rather than ignoring.

What is usually reassuring

- A small amount of clear or whitish mucus

- Mild morning crusting that wipes away easily

- Discharge that is stable or improving day to day

- No pain, no change in vision, no significant redness

Discharge and symptoms that should prompt a call to your eye doctor

Contact your eye care provider if you notice:

- Thick yellow or green (pus-like) discharge

- Eyelids stuck or matted shut in the morning, especially both eyes

- Increasing (rather than decreasing) redness or discharge

- Discharge in only one eye that is worsening

Seek urgent, same-day eye care if you have any of these

- Eye pain (beyond mild irritation)

- Any decrease or blurring of vision

- Sensitivity to light (photophobia)

- Copious, rapidly worsening pus-like discharge

- A white spot on the cornea, or a foreign-body sensation that will not settle

- You wear contact lenses and have new pain, redness, or discharge

These can be signs of a corneal infection (keratitis), which is a sight-threatening emergency and needs to be evaluated by an ophthalmologist right away. People with severe dry eye or a diseased ocular surface — the same people who use PRP drops — are at higher-than-average risk for corneal infection, which is another reason not to wait if pain or vision change appears.

Bottom line

A small amount of clear or whitish mucus or mild crusting after starting PRP eye drops is usually minor, and PRP drops are generally very well tolerated. What matters is the trend and the company it keeps: discharge that is improving and painless, with normal vision, is reassuring. Thick yellow/green discharge, eyelids gluing shut, worsening redness — and especially any eye pain, light sensitivity, or vision change — should be checked promptly, and same-day if pain or vision change is present.

A few final points:

- PRP eye drops are well tolerated. Across studies of PRP and plasma-rich-in-growth-factors drops for ocular surface disease, adverse effects were minimal — the multicenter PRGF series found only ~1% reported any side effect (mild burning), and pilot/comparative PRP studies reported no significant adverse events. Related autologous serum drops are also generally safe but can occasionally cause increased discomfort, mild epitheliopathy, or an episode of conjunctivitis, which supports framing new discharge as something to watch.[2][4][1][5][6][7]

- Discharge character is suggestive but not diagnostic. Mucopurulent (yellow/green) discharge and eyelids matted shut raise the likelihood of bacterial conjunctivitis, whereas watery discharge leans viral/allergic — but no single sign reliably distinguishes them, so color is a prompt to be evaluated, not to self-treat.[8][9][10]

- Red-flag guidance (pain, vision change, photophobia, contact lens wear) reflects standard red-eye triage: these features signal potentially serious causes such as infectious keratitis and warrant urgent ophthalmology referral. Ocular surface disease/severe dry eye is itself a recognized risk factor for keratitis, which is directly relevant to this patient population.[11][12][13][14]

One caveat: PRP eye drop safety data come from relatively small studies with heterogeneous preparation methods, so the favorable safety profile, while consistent, is not definitively established.[3] If the patient reports yellow/green discharge, matted lids, or any pain, light sensitivity, or vision change, an in-person slit-lamp exam (with fluorescein staining to exclude corneal involvement) is the appropriate next step rather than reassurance alone.[13][14]

References

1. Efficacy and Safety of Platelet-Rich Plasma and Autologous-Serum Eye Drops for Dry Eye in Primary Sjögren's Syndrome: A Randomized Trial. Kang MJ, Lee JH, Hwang J, Chung SH. Scientific Reports. 2023;13(1):19279. doi:10.1038/s41598-023-46671-2.
2. A Multicenter Report of the Use of Plasma Rich in Growth Factors (PRGF) for the Treatment of Patients With Ocular Surface Diseases in North America. Soifer M, Tovar A, Wang M, et al. The Ocular Surface. 2022;25:40-48. doi:10.1016/j.jtos.2022.04.007.
3. Human Platelets and Derived Products in Treating Ocular Surface Diseases - A Systematic Review. You J, Hodge C, Hoque M, Petsoglou C, Sutton G. Clinical Ophthalmology (Auckland, N.Z.). 2020;14:3195-3210. doi:10.2147/OPTH.S265701.
4. Autologous Platelet-Rich Plasma Drops for Evaporative Dry Eye Disease From Meibomian Gland Dysfunction: A Pilot Study. Murtaza F, Toameh D, Chiu HH, Tam ES, Somani S. Clinical Ophthalmology (Auckland, N.Z.). 2022;16:2199-2208. doi:10.2147/OPTH.S367807.
5. Comparison of Epitheliotrophic Factors in Platelet-Rich Plasma Versus Autologous Serum and Their Treatment Efficacy in Dry Eye Disease. Metheetrairut C, Ngowyutagon P, Tunganuntarat A, et al. Scientific Reports. 2022;12(1):8906. doi:10.1038/s41598-022-12879-x.
6. Autologous Serum Eye Drops for Dry Eye. Pan Q, Angelina A, Marrone M, Stark WJ, Akpek EK. The Cochrane Database of Systematic Reviews. 2017;2:CD009327. doi:10.1002/14651858.CD009327.pub3.
7. Autologous Serum Eye Drops for Ocular Surface Disorders. Cui D, Li G, Akpek EK. Current Opinion in Allergy and Clinical Immunology. 2021;21(5):493-499. doi:10.1097/ACI.0000000000000770.
8. Does This Patient With Acute Infectious Conjunctivitis Have a Bacterial Infection?. Johnson D, Liu D, Simel D. JAMA. 2022;327(22):2231-2237. doi:10.1001/jama.2022.7687.
9. Conjunctivitis. Azari AA, Barney NP. JAMA. 2013;310(16):1721-9. doi:10.1001/jama.2013.280318.
10. Bedside Diagnosis of the 'Red Eye': A Systematic Review. Narayana S, McGee S. The American Journal of Medicine. 2015;128(11):1220-1224.e1. doi:10.1016/j.amjmed.2015.06.026.
11. Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM). Miller JM, Binnicker MJ, Campbell S, et al. Clinical Infectious Diseases : An Official Publication of the Infectious Diseases Society of America. 2024;:ciae104. doi:10.1093/cid/ciae104.
12. Eye Infections. Durand ML, Barshak MB, Sobrin L. The New England Journal of Medicine. 2023;389(25):2363-2375. doi:10.1056/NEJMra2216081.
13. Conjunctivitis: Diagnosis and Management. Winters S, Frazier W, Winters J. American Family Physician. 2024;110(2):134-144.
14. The Red Eye. Leibowitz HM. The New England Journal of Medicine. 2000;343(5):345-51. doi:10.1056/NEJM200008033430507

*From Open Evidence:

A specific, confirmed case or number of cases of eye infections attributable to PRP eye drops has not been reported in the published literature: Across the available clinical studies and systematic reviews, reported adverse events are consistently minimal, transient, and largely limited to a mild burning sensation, with no serious infectious complications reported.

What the evidence actually shows on infection:

- In the largest real-world safety report — a multicenter North American series of 153 patients using plasma-rich-in-growth-factors (PRGF) eye drops — only 1 patient (0.98%) reported any side effect, and that was a burning sensation. No infections were reported.

- The randomized trial of PRP versus autologous serum in Sjögren's dry eye reported no significant safety problems and no infectious adverse events in either arm.

- The systematic review of 38 clinical studies of platelet-derived products for ocular surface disease did not identify infection as a recurring or quantified adverse outcome; the main limitations flagged were heterogeneity in preparation methods and terminology, not infectious complications.

- A 2025 review of platelet-rich derivatives across 46 studies (1,253 patients, 1,570 eyes — including eye-drop routes) similarly described a low incidence of adverse events, most transient and mild.

- A review of eye-PRP (E-PRP) explicitly stated that no serious adverse effects have been described and that the product is generally well tolerated, while emphasizing that preparation requires strict sterility (sterile disposable materials, laminar flow hood) to keep it that way.

Important interpretive caveats:

- The apparent absence of reported infections reflects small study sizes, heterogeneous protocols, and inconsistent adverse-event reporting rather than proof that infection cannot occur. These studies are underpowered to detect rare events, so a true zero cannot be inferred.

- The main theoretical infection risk with any autologous blood-derived drop is contamination during preparation or storage, which is why sterility is emphasized. One laboratory study specifically cultured PRP drops stored at 4°C for up to 4 weeks and confirmed they maintained sterility, supporting refrigerated storage when prepared correctly.

- Separately, patients who use PRP drops (severe dry eye, neurotrophic keratopathy, non-healing epithelial defects, ocular graft-versus-host disease) already have a compromised ocular surface that independently raises their baseline risk of microbial keratitis — so a new infection in such a patient may reflect the underlying disease rather than the drop itself.

Bottom line: there is no reported epidemic or defined case count of PRP-eye-drop infections, and thicker discharge is far more likely to be minor mucus/irritation — but the color is important as many patients with Dry Eye Disease have a higher-risk of infection even without PRP eye drops. 

Thus any pain, vision change, photophobia, mucopurulent (yellow/green) discharge, or matted lids should prompt a same-day slit-lamp microscope exam with fluorescein staining.