Lens Materials to Solve Dryness Complaints
JEFF SCHAFER, OD, MS
Dryness has historically complicated contact
lens wear to the extent that it often causes patients to stop wearing lenses. It's
been reported that up to 75 percent of contact lens wearers experience at least
occasional ocular dryness.
How we manage contact lens dryness has changed dramatically
over the last five years. New contact lenses have entered the market and have given
us a variety of options to help improve the comfort of our patients.
When silicone hydrogel materials first entered the market, anecdotal
evidence of improved dryness symptoms began surfacing in patients refit into balafilcon
A (PureVision, Bausch & Lomb) and lotrafilcon A (Night & Day, CIBA Vision).
Many clinicians noticed that the combination of low water content and high Dk resulted
in improved comfort in patients who had previously experienced dryness in thin,
high-water hydrogel lenses. My own clinical and research experience has shown that
dryness symptoms decrease in both frequency and severity when hydrogel lens patients
are refit into silicone hydrogels, even with extended wear.
Many practitioners perceive that silicone hydrogels are less comfortable
than are hydrogels because of the increased lens awareness that results from higher
modulus. So even if a patient's dryness symptoms improve, there is a trade off with
more awareness of a stiffer lens. Silicone hydrogel manufacturers have combated
this issue by introducing a newer generation of silicone hydrogel materials that
includes lotrafilcon B (O2Optix, CIBA), galyfilcon A (Acuvue Advance,
Vistakon), and senofilcon A (Acuvue Oasys, Vistakon). These materials exhibit a
lower modulus than the previous generation, which may result in improved comfort
through reduced lens awareness. Both Acuvue Advance and Oasys contain Hydraclear,
an internal wetting agent, which the manufacturer claims helps to maintain comfort
and reduce dryness symptoms throughout the day.
I recommend silicone hydrogels to patients who complain of mild
to moderate dryness. When appropriate, I educate them about an initial adaptation
period of a few days to one week, but to then expect an improvement in comfort over
the next several months. I don't expect patients who complain of significant dryness
to be symptom free one week following a refit. I believe it takes several weeks
for an inflamed ocular surface to improve following a refit into a silicone hydrogel
Hydrogel Lens Options
I've also had good results using the hydrogel materials omafilcon
A (Proclear, CooperVision) and hioxifilcon A (Extreme H2O, Hydrogel Vision
Corp.). Both utilize unique material properties that allow them to maintain a high
water content throughout the wear cycle. At this time Proclear lenses are the only
lenses to carry the FDA indication, "may provide improved comfort for contact lens
wearers who experience mild discomfort or symptoms relating to dryness during lens
These lenses may offer more immediate dryness relief with no adaptation
period, although lower-modulus silicone hydrogels are closing the gap on initial
Taking Extra Steps
The etiology of dryness symptoms in lens wearers
can be multi-factorial. Switching lens materials may not be enough to solve a patient's complaints.
Carefully recommend not only the right material for each patient, but also a compatible
disinfection system. Re-educate patients on lens care and hygiene, manage any lid
disease and monitor the stability of the tear film to keep your patients comfortably
Dr. Schafer is a clinical
assistant professor and chief of the contact lens service at The Ohio State University
College of Optometry.
Contact Lens Spectrum, Issue: March 2006