contact lens care
Managing Solution-Related Dryness
BY JENNIFER L. SMYTHE, OD, MS, FAAO

Figure 1. Solution-related keratitis in a soft lens wearer.

Dryness remains the most common complaint from contact lens wearers. It is the primary reason cited for discontinuing contact lens wear. However, it is rare to find a young, healthy individual with "true" keratoconjunctivitis sicca (dry eye). Some other mechanism(s) must be responsible for the dry eye symptoms in many of our contact lens wearers. This is reinforced by the fact that symptomatic soft lens wearers rarely report dry eye symptoms when switched to spectacles or daily disposable lenses.

Previously, I described how changing a patient's gas permeable (GP) lens care regimen can solve "foggy lenses." Consider this same philosophy when managing other solution-related phenomena.

	Figure 2. Solution-related keratitis in a GP lens wearer.

Foggy Corneas and Lids

Toxic reactions to lens care ingredients, particularly preservatives, occur with both soft and GP lens wear. Recently, care regimens preserved with high concentrations of PHMB have been identified as culprits in causing corneal staining or what could be considered "solution-related keratitis." Other ingredients in multi-purpose solutions, such as buffers and surfactants, should also be suspected.

Soft lens patients may display diffuse corneal staining that begins in the inferior region of the cornea (the area closest to the tear meniscus) then works its way around the periphery, with the central cornea the last region affected (Figure 1). In GP solution sensitivity reactions, the corneal staining is often confined to the area underneath the lens or the central cornea, especially if the lens is fitted with apical clearance (Figure 2).

Figure 3. Tarsal plate hyperemia secondary to MPS use.

Researchers in Denmark have shown that an inflammatory reaction to multi-purpose solutions, particularly PHMB-preserved formulations, can also cause tarsal plate changes and increasing palpebral hyperemia (Figure 3). These patients may or may not display corneal staining. The patient often complains of itching, burning and/or dry, irritated eyes and blurry vision with lens wear. These are dry eye symptoms in individuals with adequate tear production.

What's the Solution?

The simplest fix for soft lens wearers is eliminating solutions and recommending a single-use modality such as daily disposables or continuous wear. When this is not an option, switching the lens care regimen is critical. Changing to another preserved MPS with a lower concentration of PHMB or a different preservative may help. I find changing lens care to peroxide-based disinfection, such as CIBA Vision Clear Care or the Purilens ultraviolet disinfection system, is a more effective means of both reducing the incidence of physiologic changes and more importantly, offering the patient longer, less dry and more comfortable wear schedules. 

Dr. Smythe is an associate professor of optometry at Pacific University and in private group practice in Beaverton, Oregon.