Polyvinyl alcohol
Also known as: Liquifilm Tears · Refresh Ophthalmic · Sno Tears · PVA
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Keratoconjunctivitis sicca (KCS) / Dry eye lubrication | 1 drop per eye | topical | q1h | As needed | 🌍 EU |
- Keratoconjunctivitis sicca (KCS) / Dry eye lubrication: Patient compliance is poor if administered >q4h; consider using a longer acting tear replacement.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Dry eye lubrication | 1 drop per eye | topical | q1h | As needed | 🌍 EU |
- Dry eye lubrication: Patient compliance is poor if administered >q4h; consider using a longer acting tear replacement.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Polyvinyl alcohol is a synthetic water-based tear substitute used for the lubrication of dry eyes. In cases of keratoconjunctivitis sicca (KCS), it improves ocular surface lubrication, tear retention, and patient comfort while lacrostimulation therapy (e.g., topical ciclosporin) is initiated.
Clinical Pearl: It is more adherent and less viscous than hypromellose. However, because it requires very frequent application (often every hour), patient compliance can be poor. Consider longer-acting tear replacements (like cross-linked hyaluronic acid or carbomer gels) if frequent dosing is impractical.
Mechanism of action
Acts as a lacromimetic (tear substitute). It mimics the aqueous layer of the trilaminar tear film, providing physical lubrication and moisture to the corneal and conjunctival surfaces.
Safety & warnings
Precautions
Patient compliance is poor if administered >q4h; consider using a longer acting tear replacement.
Normal ophthalmic preparation handling precautions should be observed to prevent contamination of the dropper tip.
Monitoring
- Clinical signs of dry eye (corneal health, conjunctival hyperemia, comfort)
- Schirmer tear test (STT) to monitor underlying KCS progression
Pharmacokinetics
Half-life
Absorption
Acts locally on the ocular surface. Systemic absorption is negligible.
Distribution
Remains on the corneal and conjunctival surfaces.
Metabolism
Not metabolized systemically.
Elimination
Cleared from the eye via the nasolacrimal duct and normal tear turnover.
Overdose
No specific information available. Overdose via topical ophthalmic administration is highly unlikely to cause systemic toxicity. Excess fluid will simply drain from the eye.
Available products
Formulations
- Ophthalmic solution: 1.4% (0.4 ml vials, 15 ml bottle)
Human-labeled
- Liquifilm Tears 1.4%
- Refresh Ophthalmic 1.4%
- Sno Tears 1.4%
Regulatory status
Available Over-The-Counter (OTC) as human artificial tears.
Human products used under the cascade.
Classified as a Pharmacy (P) medicine in the UK for human use; used under the prescribing cascade in veterinary medicine.
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature. Keep container tightly closed. Single-use vials should be discarded immediately after use if they do not contain preservatives.
Client information
Polyvinyl alcohol is an artificial tear drop used to keep your pet's eyes moist, especially if they have 'dry eye' (KCS).
- Wash your hands before and after applying the drops.
- Do not touch the tip of the bottle to your pet's eye or any other surface to prevent bacterial contamination.
- These drops often need to be applied very frequently (sometimes every hour) to be effective. If you find this schedule difficult, talk to your vet about longer-lasting alternatives.
- Wait at least 5-10 minutes before applying any other eye medications.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.