Contact Lens Care & Compliance
Soft Lens Rewetting Drops
By Michael A. Ward, MMSc, FAAO
Most preserved artificial tears are not compatible with contact lenses. In addition, patients may not realize that there’s a difference between artificial tears and contact lens rewetting agents.
Comparing Rewetting Drops and Artificial Tears
Rewetting agents are surface-active chemical substances that increase the spreading and penetrating properties of a liquid by lowering its surface tension. Most rewetting drops are preserved, multi-dose products that contain sodium and potassium salts along with buffers. Some also contain other electrolytes and wetting agents (surfactants, demulcents, and/or hyaluronic acid).
Surfactants (surface active agents) are amphiphilic: they contain both hydrophobic “tails” and hydrophilic “heads,” which allow them to reduce the interfacial tension between oil and water. If used in excess, they can emulsify the tear lipid layer and potentially exacerbate dryness symptoms.
Generally, preservative-free artificial tears may be used over rigid and soft lenses without concern, although it may be off-label (Ward, 2011). Although soft lens rewetting drops may be safely used over GP lenses, many GP rewetting drops may not be used over soft lenses. All multi-dose products are preserved. Of these, I prefer dissipating preservatives (e.g., oxychloro complex or perborates) when used frequently.
Table 1 lists soft lens rewetting products from the 2013 Contact Lenses & Solutions Summary. CLS
|
MANUFACTURER |
PRODUCT NAME |
FORMULATION |
|---|---|---|
|
Abbott Medical Optics (AMO) |
Blink Contacts Lubricant Eye Drops |
Purified water, sodium hyaluronate, sodium chloride, potassium chloride, calcium chloride, magnesium chloride, boric acid and is preserved with OcuPure (stabilized oxychloro complex) 0.005% |
|
Complete Lubricating and Rewetting Drops |
Purified water, sodium chloride; preserved with polyhexamethylene biguanide 0.0001%, buffered with tromethamine as an emulsifier, hydroxypropyl methylcellulose as a lubricant, tyloxapol as a surfactant, and edetate disodium as a chelating agent |
|
|
Allergan |
Refresh Contacts |
Carboxymethylcellulose sodium, sodium chloride, boric acid, potassium chloride, calcium chloride, magnesium chloride, purified water, and is preserved with Purite (stabilized oxychloro complex) |
|
Alcon |
Aquify Long Lasting Comfort Drops |
Sodium hyaluronate, sodium chloride, sodium phosphate, and sodium perborate stabilized with phosphonic acid as a preservative |
|
Clerz Plus Lens Drops |
Citrate/borate buffer and sodium chloride with edetate disodium and polyquad as preservatives, RLM 100 (PEG-11 laurel ether carboxilic acid), and Tetronic 1304 |
|
|
Opti-Free Express Rewetting Drops |
Citrate buffer and sodium chloride with edetate disodium 0.05% and Polyquad 0.001% preservative |
|
|
Opti-Free PureMoist Rewetting Drops |
Citrate/borate buffer and sodium chloride with edetate disodium 0.05% and Polyquad (polyquaternium-1) 0.001% preservatives, RLM-100 (PEG-11 lauryl ether carboxylic acid), and Tetronic 1304 |
|
|
Opti-Free Replenish Rewetting Drops |
Citrate/borate buffers and sodium chloride with edetate disodium and Polyquad as preservatives, RLM 100 (PEG 11 laurel ether carboxylic acid), and Tetronic 1304 |
|
|
Bausch + Lomb |
ReNu Rewetting Drops |
Boric acid, poloxamine, sodium borate, and sodium chloride; preserved with sorbic acid 0.15% and edetate disodium 0.1% |
|
ReNu MultiPlus Lubricating and Rewetting Drops |
Povidone, boric acid, potassium chloride, sodium borate and sodium chloride; preserved with edetate disodium 0.1% and sorbic acid 0.1% |
|
|
Sensitive Eyes Drops |
Boric acid, sodium borate, and sodium chloride preserved with sorbic acid 0.1% and edetate disodium 0.025% |
For references, please visit www.clspectrum.com/references.asp and click on document #219.
Mr. Ward is an instructor in ophthalmology at Emory University School of Medicine and director, Emory Contact Lens Service. He is also a consultant or advisor to Alcon and B+L. You can reach him at mward@emory.edu.
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