contact lens Q&A

Maintaining RGP Hygiene and Health

BY CHRISTOPHER SNYDER, OD, MS

RGP patients marvel at how well their lenses feel after their routine annual cleaning and polishing in the office. Good daily lens care, use of enzymes and periodic polishing will avoid RGP coating keratitis and keep your coating keratitis and keep your RGP patients happy, healthy and loyal. As you are about to read, poor lens care is a welcome mat for keratitis and other inflammatory and bacterial problems.

A long-time RGP wearer presented with decreased comfort OD. Biomicroscopy revealed a central keratitis (Fig. 1). What is the proper treatment?

ANSWER: When an RGP lens wearer presents with no complaint other than mild discomfort associated with lens wear, check the lens condition to determine whether or not the discomfort is related to a chip or edge defect. If inspection does not reveal a defect, evaluate the condition of the posterior lens surface.

Even with diligent daily lens rubbing and rinsing, a buildup of tear proteins will inevitably coat the inside of the lens. This coating is visible only with the lens off of the eye while the surface is dry (Fig. 2). Since coating is not evident by evaluating the lens on the eye, it doesn't affect vision. This back surface coating impedes tear exchange under the lens and likely causes a mechanical abrasive effect on the central corneal epithelial cells.

Keep It Clean!

Such buildup on the back surface of an RGP lens is dependent upon tear chemistry, lens cleaning technique, regularity of lens care and perhaps lens material. Preventing this problem entails maintaining a clean and well-wetting lens surface. Key steps include: daily surfactant cleaning, periodic proteolytic enzyme soak and yearly in-office polishing. One thing is certain -- the coating takes months to build up, which is why in-office polishing on a yearly basis is an excellent way to keep lens surfaces in great condition. Polishing lens surfaces provides immediate relief, allows for uninterrupted lens wear and sets the stage for complete resolution of the keratitis. Lens replacement is another treatment option that you can consider.

If RGP lens planned replacement is part of the management, enzymes and polishing may be skipped, but daily surfactant cleaning should not be eliminated from the lens care regimen.

Recently, the use of enzymes by RGP lens wearers has become very convenient with the availability of two daily-use liquid enzyme products, Opti-Free SupraClens by Alcon Vision Care and Boston One Step liquid enzymatic cleaner by Polymer Technology. These products act in the lens case concurrently with the disinfecting and soaking solution.

Since some patients may not be prone to lens buildup, prescribe proteolytic enzymes only as needed in addition to digital, daily surfactant cleaning during the interval between regular lens polishing or between regular lens replacements.

Dr. Snyder is a professor of optometry and serves as chief of contact lens patient care at the School of Optometry at the University of Alabama at Birmingham.