Contact Lens Care & Compliance
Approved GP Wetting Drops
By Michael A. Ward, MMSC, FAAO
A colleague recently asked me, “What lubricating or rewetting products are approved for in-eye use over GP lenses?” My initial response was that any preservative-free artificial tear (PFAT) may be used without concern. Also, I can't think of any clinical contraindications to using rewetting agents that are approved for use with soft lenses on GP lenses, but it would be off-label use.
Although these are valid responses, I did not answer the posed question. Therefore, Table 1 summarizes most of the lens rewetting products on the market that are approved for GPs.
Tears Versus Rewetting Agents
There is a difference between artificial tears and rewetting agents. 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, and some also contain other electrolytes and wetting agents (surfactants, demulcents, and/or hyaluronic acid [HA]).
Surfactants (surface active agents) are amphiphilic: they contain both hydrophobic “tails” and hydrophilic “heads,” which allows them to reduce the interfacial tension between oil and water. If used in excess, this property can emulsify the tear lipid layer and potentially exacerbate dryness symptoms.
All multi-dose products will be preserved. Of these, I prefer dissipating preservatives (e.g. oxychloro complex, perborates) for patients who are frequent users of these products. There is no practical limit on the frequency of PFAT use.
Most preserved artificial tears are not compatible with contact lenses. Our patients may not realize that there's a difference between artificial tears and contact lens rewetting agents. It is our responsibility to educate them. CLS
Mr. Ward is an instructor in ophthalmology at Emory University School of Medicine and Director, Emory Contact Lens Service. He is also a member of the AMO Advisory Panel. You can reach him at email@example.com.