Refresh Eye Drops Active Ingredient
Refresh eye drops contain carboxymethylcellulose sodium (CMC) as the primary active lubricating ingredient 1.
Formulation Details
The specific formulation varies by product line:
- Refresh Tears® (Original Strength): Contains carboxymethylcellulose sodium as the lubricant 1
- Refresh Plus®: Contains carboxymethylcellulose sodium in a preservative-free formulation 2
- Refresh Celluvisc®: Contains 1.0% high-viscosity CMC 3
- Refresh Liquigel®: Contains 1.0% total CMC made by blending 0.35% high-viscosity with 0.65% medium-viscosity CMC 3
Clinical Evidence for CMC-Based Formulations
Research demonstrates that CMC-based artificial tears like Refresh Plus improve tear ferning patterns in dry eye patients for at least 3 hours 2. The study showed significant improvement in tear ferning grades after application (P=0.02), with strong correlations at 120 minutes (r=0.560, P=0.019) and 180 minutes (r=0.726, P=0.001) post-instillation 2.
Viscosity Considerations
The blended viscosity formulation (Liquigel) causes approximately half the duration of blur compared to high-viscosity formulations (Celluvisc) while maintaining therapeutic efficacy 3. Both formulations temporarily decrease contrast sensitivity for high-frequency gratings (14 CPD), but Liquigel's shorter blur duration may be more acceptable for patients requiring frequent dosing 3.
Comparative Efficacy
Recent evidence shows that CMC-based tears demonstrate similar short-term efficacy to other formulations (sodium hyaluronate, polyethylene glycol) in improving noninvasive tear breakup time 4. All tested artificial tears showed significant NIBUT improvement at all time points, with no significant differences between CMC concentrations (0.5% vs 1.0%) 4.