Examples of Artificial Tears for Dry Eye
Artificial tears are available in multiple formulations, with methylcellulose-based and hyaluronate-based products serving as first-line options, and preservative-free formulations strongly recommended when using more than four times daily. 1, 2
Primary Active Ingredient Categories
Cellulose-Based Formulations
- Carboxymethylcellulose (0.5-1%) and carmellose sodium provide temporary relief of burning, irritation, and discomfort due to dryness 2, 3
- Methylcellulose-based tears are recommended by the American Academy of Ophthalmology as first-line therapy, to be used at least twice daily and increased up to hourly as needed 2, 4
Hyaluronic Acid-Based Formulations
- Hyaluronate-based artificial tears stabilize the tear film, increase corneal wettability, and reduce friction during blinks due to hygroscopic and viscoelastic properties 2, 5
- These formulations are equally recommended alongside methylcellulose as first-line therapy 2, 4
Polyvinyl Alcohol-Based Products
- Polyvinyl alcohol (1.4%) provides temporary relief of burning and irritation, though 0.2% polyacrylic acid-based tears were found more effective than 1.4% polyvinyl alcohol in treating dry eye symptoms 6, 7
Dual-Polymer Combinations
- Hydroxypropyl guar-hyaluronic acid (HPG-HA) dual-polymer formulations (such as SYSTANE HYDRATION) combine demulcents (propylene glycol and polyethylene glycol 400) with polymers that form a cross-linked gel matrix for prolonged retention and lubrication 5
Formulation Types by Viscosity
Liquid Drops (Daytime Use)
- Standard liquid formulations are suitable for daytime use with less visual blur 1, 2
- Frequency should be adjusted from twice daily to hourly based on symptom severity 2, 4
Gels (Intermediate Duration)
- Gel formulations provide longer-lasting effect due to increased viscosity, reducing the number of applications needed 1
- These may cause more transient vision blur but offer extended relief 1
Ointments (Overnight Use)
- Ointments are recommended for overnight symptom control 1, 2
- Morning lid hygiene should follow overnight ointment use to prevent blepharitis 2, 4
Preservative Considerations
When to Use Preservative-Free
- Preservative-free formulations are mandatory when using artificial tears more than four times daily to avoid ocular surface toxicity 1, 2, 4
- Switching from preserved to preservative-free hyaluronate-containing tears decreased OSDI scores from 56.0 to 28.2 and reduced superficial punctate keratitis from 73% to 46.1% after just 3 weeks 8
Preserved Formulations
- Tears with preservatives may be sufficient for mild dry eye with an otherwise healthy ocular surface when used less than four times daily 1
- "Vanishing" preservatives (purite, sodium perborate) and safer quaternary compounds (polyquaternium-1) are preferred over benzalkonium chloride 9
- However, patients using artificial tears with "soft" or "vanishing" preservatives presented the same clinical pattern (OSDI levels and frequency of superficial punctate keratitis) as those using benzalkonium chloride 8
Specialized Formulations
Lipid-Containing Drops
- Lipid-based artificial tears are specifically beneficial for patients with meibomian gland dysfunction, as they supplement the deficient lipid layer 2
Cationic Emulsions
- Preservative-free cationic emulsions (such as Cationorm) containing cetalkonium chloride increased goblet cell count by 40% and decreased inflammatory cell infiltration, positioning them as promising options for patients with chronic subclinical ocular inflammation 10
Common Pitfalls to Avoid
- Overusing preserved artificial tears (more than 4 times daily) causes ocular surface toxicity and worsens dry eye 2, 4
- Failing to escalate therapy when symptoms persist after 2-4 weeks of optimized artificial tear use—at this point, anti-inflammatory agents like cyclosporine should be added 4
- Neglecting underlying meibomian gland dysfunction or blepharitis limits the effectiveness of artificial tears and requires concurrent treatment with warm compresses and lid hygiene 1, 2