contact lens case reports

The Advantages of an Ultraviolet Disinfection System

BY PATRICK J. CAROLINE, FAAO, & MARK P. ANDRÉ, FAAO
March 2000

F.L. is a 24-year-old female with a two-year history of moderately successful toric soft contact lens wear. Her present contact lenses are base curve 8.9mm, diameter 15.0mm, with powers OD -3.50 -3.75 x 175, OS -3.00 -350 x 180. Visual acuity with her lenses was 20/20- OU. Her lens care system consisted of Allergan's Complete Comfort Plus Multi-Purpose Solution and Complete Weekly Enzymatic Cleaner.

F.L. presented to our clinic with symptoms of mild ocular dryness resulting in decreased lens tolerance and wearing time. Because her present contact lenses were 14 months old, we ordered new lenses and instructed her to use a preservative-free lens lubricant. After wearing the new lenses, F.L. reported little improvement in her dry eye symptoms. We suspected that she may be experiencing a mild reaction to her lens care regimen, something we call a multipurpose nonkeratitis. The hallmark of this type of sensitivity appears to be the gradual onset of ocular dryness symptoms in the presence of normal slit lamp findings. Individuals presenting with these symptoms often experience significant relief after switching to daily disposable contact lenses or to a preservative-free hydrogen peroxide disinfection system. In this case, we introduced F.L. to the PuriLens Contact Lens System (PuriLens), a new preservative-free, ultraviolet disinfection system.

The PuriLens System

It has been proven that the UV-C segment of the ultraviolet spectrum has significant germicidal effects. This form of radiant energy induces photochemical reactions involving biologically active molecules within microorganisms. The resulting molecular alterations inhibit cell growth, and in higher doses, result in cellular death. Studies have shown that a low discharge lamp generating UV-C light at 253.7nm can effectively destroy bacteria, viruses, fungi, molds, yeasts and algae. The PuriLens System is the first FDA approved lens care regimen to utilize UV-C light for disinfection and is approved for use with all soft contact lenses (Fig. 1). A unique lens holder prevents direct lens exposure to the UV light, thereby preventing any adverse changes in lens parameters.

The three major components of this system are the UV generating lamp, a subsonic agitation cleaning mechanism and a nonpreserved Purilens solution (Fig. 2). Daily digital cleaning is replaced by a potentially more effective 3600 cycles/minute subsonic agitation mechanism built into the unit.

F.L. experienced complete resolution of her dry eye symptoms after switching to the PuriLens System. We have found this system to be ideal for patients who require a simple, inexpensive form of preservative-free disinfection and for those who wear lens designs that aren't available in a daily disposable modality.

Patrick Caroline is an associate professor of optometry at Pacific University and an assistant professor of ophthalmology at the Oregon Health Sciences University.

Mark André is director of contact lens services at the Oregon Health Sciences University.