Dry Eye Dx and Tx
How Daily Disposable Lenses Can Address Contact Lens Dryness
BY WILLIAM TOWNSEND, OD, FAAO
Despite advances in soft contact lens materials, design and surface characteristics and improvements in care solutions, discomfort and dryness lead many patients to stop wearing their lenses.
What Studies Tell Us
In a multisite clinical study, researchers investigated potential causes for contact lens discontinuation (Young et al, 2002). They found the majority of patients who discontinued lens wear (51 percent) did so because of discomfort, and the most commonly reported type of discomfort was dryness (40 percent).
More recently, researchers surveyed 4,207 contact lens wearers to determine why they stopped wearing their lenses (Dumbleton et al, 2013). Forty percent of the patients surveyed had discontinued lens wear for at least 4 months. The most commonly reported reasons for discontinuation were discomfort (24 percent) and dryness (20 percent).
Dryness and Discomfort
Patients experiencing contact lens dryness may report various symptoms, such as discomfort, irritation, burning, stinging, foreign body sensation and visual blurring (Sindt 2007), which may be caused by poor prelens tear stability, lens material or lens deposits. Contaminants begin to adhere to a lens surface within minutes of application (Brennan and Coles 2000), and the degree and type of deposits are influenced by the water content, ionic properties and silicone content of a lens. Because lens deposits decrease prelens tear film breakup time, they may exacerbate the sensation of dryness (Sindt 2007).
Lipids can significantly affect contact lens wear, and our appreciation of their function and impact on the ocular surface and contact lenses has expanded over the last decade (Panaser and Tighe 2012; Pucker and Nichols, 2012). For example, we have learned a lipid coating increases over time, and the aqueous tears cannot form a stable layer over a lipid-coated contact lens (Brennan and Coles, 2000).
Multipurpose contact lens solutions are designed to remove deposits, but they are never 100 percent successful in doing so (Brennan and Coles, 2000). In addition, improper lens care may leave some deposits on the lenses, leading to poor comfort and vision. Wu et al (2010) found that many patients wearing daily wear lenses exhibited poor hand hygiene and inadequate lens and storage case cleaning and had difficulty remembering when to return for aftercare.
Banish Deposits Daily
How can we help patients continue to wear their lenses comfortably when they have dryness or comfort issues? One option is to prescribe daily replacement lenses.
Daily disposable lenses may reduce the risk of noncompliance and complications associated with surface deposits, thus improving comfort and the total lens-wearing experience for patients.
Fahmy and colleagues (2010) refitted symptomatic patients who replaced their lenses at intervals of 1 to 4 weeks into Dailies AquaComfort Plus lenses. At the end of 4 weeks, they found statistically significant improvements in symptoms as well as in limbal and bulbar redness and conjunctival staining. CLS
For references, please visit www.clspectrum.com/references.asp and click on document SE2013.
Dr. Townsend practices in Canyon, Texas, and is an adjunct professor at the University of Houston College of Optometry. He is president of the Ocular Surface Society of Optometry and conducts research in ocular surface disease, lens care solutions, and medications. He is also an advisor to Alcon, B+L, CooperVision, Tearlab Corporation, and Vistakon. Contact him at firstname.lastname@example.org.