dry eye dx and tx

Does My Patient Have Dry Eye or Contact Lens Dryness?

BY WILLIAM TOWNSEND, OD, FAAO, & ARTHUR EPSTEIN, OD, FAAO

Many contact lens patients complain of burning, scratchy or irritated eyes, which are traditional symptoms of dry eye. Many once successful contact lens wearers have dropped out of lens wear primarily because of dryness symptoms, and these patients may remain out of lenses indefinitely because clinicians often misunderstand the underlying etiology of these symptoms and how to effectively treat them.

Modern dry eye therapies are optimized for their intended targets. In some instances, they have become so effective that dry eye patients who were once unsuitable for contact lens wear are now able to successfully wear lenses — in some cases full time.

An ideal therapeutic strategy is to first identify the underlying cause of symptoms and then determine the best course of treatment. The initial inquiry is, "Does the patient have dry eyes, or are these symptoms secondary to contact lens wear?"

Identifying True Dry Eye

If a patient presents with any or all of the following signs, symptoms or characteristics, it's likely that the patient has true dry eye.

• Dry eyes both day and night.
• Over 40 years of age.
• Patient lives in a dry environment.
• Rapid tear breakup time.
• Conjunctival staining.

In these patients it's important to use a formulation designed and optimized to specifically manage dry eye, independent of any related contact lens issues. Drops such as Systane Ultra (Alcon) and Blink Tears (Advanced Medical Optics) are formulated to extend protection over the ocular surface, which allows for healing.

Contact Lens-Related Dryness

Patients who have contact lens-related dryness often present with signs, symptoms and characteristics such as:

• Dryness occurring after six hours or more of lens wear.
• Younger demographic.
• Reduced vision as the day progresses.
• Decreased lens movement and visible lens surface dryness.
• Corneal staining.

Managing these patients includes prescribing a solution formulated to improve and sustain long-term lens surface wettability. We find that Opti-Free Replenish (Alcon) and Aquify (CIBA Vision) work well for patients with dry eye complaints. Some also use a hydrogen peroxide system for such patients.

It's also helpful to prescribe a rewetting drop; they are designed specifically for use with contact lenses and their formulations may differ substantially from conventional dry eye drops. Modern contact lens rewetting drops target the lens surface as much as or even more than they target the ocular surface. For example, Replenish rewetting drops (Alcon) contain lens-specific rewetting agents Tetronic 1304 and C9ED3A, also found in Replenish solution. Blink Contacts (AMO) and Aquify rewetting drops (CIBA) contain the advanced wetting agent hyaluronic acid.

Using a dry eye drop for contact lens dryness or using a rewetting drop for a dry eye problem may actually be counterproductive.

Finally, evaluate the lens material the patient is wearing. Lens manufacturers have modified lens materials and surfaces to improve intrinsic hydrophilicity, thereby improving lens comfort. The recent introduction of CooperVision's Biofinity lenses and Vistakon's Acuvue Oasys material represent substantial advances in managing contact lens patients who have dry eye. CLS

Dr. Townsend practices in Canyon, Texas and is an adjunct faculty member at UHCO. E-mail him at drbilltownsend@gmail.com. Dr. Epstein is a founding partner of North Shore Contact Lens & Vision Consultants, P.C., a referral based contact lens specialty and primary eyecare practice on Long Island, NY. He is a consultant to a number of companies including Alcon Labs mentioned in this article.