Maintaining Lens Hydration
Contact Lens Practice Pearls
Maintaining Lens Hydration
By Gregory J. Nixon, OD, FAAO
It has been well documented that patient comfort is a major determinant of successful contact lens wear. Despite prescribing patients a lens material and disinfection system that are compatible with their ocular surface chemistry, most patients are still prone to some degree of end-of-day dryness symptoms.
To help extend the comfortable wear time of contact lenses, it is common for patients to instill artificial tears or rewetting drops. Therefore, it is important to educate patients on selecting the best over-the-counter (OTC) products to maximize their comfort.
Go Preservative Free
It has always been my recommendation that during contact lens wear, patients avoid using drops that contain preservatives. This can be difficult since most OTC preparations are preserved. In fact, many are still preserved with benzalkonium chloride (BAK), which can disrupt the ocular surface and actually impair comfort rather than promote it.
It is beneficial to avoid all chemical preservatives for on-eye contact lens hydration. Luckily, there are ample preservative-free artificial tears that can effectively manage dry eye symptoms. However, these are usually packaged as multiple individual-dose vials that can be inconvenient to carry throughout the day and can become costly when used often. More importantly, recommending these drops during lens wear represents an off-label use because most of these formulations are not indicated to be used during contact lens wear.
Cleverly Preserved Alternatives
Several products are approved for use with contact lenses that can provide the convenience of a bottled preparation with the safety and efficacy of a single-use, preservative-free formula. For example, Refresh Contacts (Allergan) is preserved with the proprietary agent Purite that becomes denatured when exposed to light. The solution maintains protection against contamination while within its dark green opaque bottle, but when it is released from the bottle, light breaks down the preservative into sodium and chloride ions, oxygen, and water that dissipate into the tears.
Similarly, Blink Contacts (Abbott Medical Optics) is preserved with its own light-induced disappearing preservative OcuPure. TheraTears Contact Lens Comfort Drops (Advanced Vision Research) is preserved with sodium perborate, which is broken down by enzymes within the tears, resulting in water and oxygen as end products.
Regardless of the mechanism, these cleverly preserved formulations provide a good alternative for on-eye lens rewetting.
In addition to knowing what products to recommend, it is also important to recommend when patients should use them. It is often beneficial to instill rewetting drops before symptoms occur. For office workers, it is best to dose before commencing a long, detailed visual task such as an afternoon of computer work when there is likely to be a reduction in blink frequency that can promote lens dehydration. Likewise, to help combat dryness at home in the evening, have patients instill drops at the end of the work day prior to driving home.
Additionally, when patients are faced with an especially long day of lens wear, there can be appreciable benefits in removing the lenses for a short time during the day. For example, before heading off to an evening meeting, have patients remove and soak their lenses in fresh disinfecting solution for 15 to 20 minutes and instill artificial tears while the lenses are out. This combination of independently hydrating the eyes and lenses in the mid to late day can significantly improve the final hours of wear time on a 16- to 18-hour day of lens wear. CLS
|Dr. Nixon is an associate professor of clinical optometry and director of extern programs at The Ohio University College of Optometry. He is also in a group private practice in Westerville, Ohio. He is on the Allergan Academic Advisory Board, the B+L Advisory Board, and the Alcon Speakers Bureau. You can reach him at email@example.com.|
Contact Lens Spectrum, Volume: 27 , Issue: May 2012, page(s): 42