reader and industry forum
SCARE: A Contact Lens Problem in Your Office?
BY MARK ROSS, OD
It may sound frightening, but it's just another clinical entity we may face in the course of seeing our contact lens patients. In recent years, more contact lens manufacturers have begun producing silicone-based contact lenses; and in an effort to improve oxygen transmission to the cornea and theoretically to improve successful contact lens wear, many practitioners have shifted their patients from HEMA-based contact lenses to this lens type. Heavy advertisements in the media are compelling patients to ask for these newer lenses.
What is SCARE?
Over time, in the course of my practice, I have noticed an increase in an entity that I have given the acronym "SCARE." It stands for Silicone Contact lens-Associated Red Eye. The symptoms can manifest as decreased wearing time, increasing intolerance to contact lenses, irritation, foreign body sensation, dryness, itching, discomfort, and blurred or hazy vision. Clinical signs may include conjunctival injection, papillary reaction on the upper or lower lid, diffuse corneal staining, decreased tear breakup time, and corneal haze.
Postulated causes for SCARE may include the increased lens modulus of some of the silicone hydrogel lens materials, a greater affinity for lipid deposition with these lenses, or other unknown etiologies. Some of the newer silicone-based lens materials may have a lower propensity to cause these issues.
Most of us are familiar with the term CLARE (contact lens-associated red eye). Traditionally, treatment of CLARE includes a combination of an antibiotic/antiinflammatory medication, preservative-free artificial tears, an allergy medication, a more frequent replacement schedule, digital rubbing of contact lenses after removal, and/or a change in lens care system. Occasionally, abstinence from contact lens wear for a period of time is necessary. Reinforcing proper care techniques and hygiene is also important.
In the case of SCARE, however, I have noticed that sometimes even after applying all of the aforementioned treatments and patient education, the signs and symptoms may recur if the patient resumes lens wear with the same or another silicone-based contact lens. In some cases it is only after switching the affected patients to a HEMA or other non-silicone-based polymer that their issues resolve.
Certainly, silicone-based contact lenses have a place in our fitting armamentarium. They allow higher levels of oxygen transmissibility, so their clinical advantages are readily apparent especially for high prescriptions or extended wear.
However, we must realize that while the cornea receiving an appropriate amount of oxygen is important, it is not the only requisite for successful contact lens wear. Comfort, clarity, and overall ocular health are a necessity.
We still have a significant need and usage for HEMA or other non-silicone-based contact lens designs, especially to fit the portion of patients who might be prone to or who present with SCARE. CLS
Dr. Ross is co-owner of Tucker-Ross Eye Associates, P.C., a private practice specializing in contact lenses in Crystal Lake, Ill.