contact lens care
How to Treat Plasma-Treated GP Lenses
BY SUSAN J. GROMACKI, OD, MS, FAAO
The plasma treatment of GP lenses has been available for quite a few years (Silsoft, Bausch & Lomb; Menicon). However, beginning with the Paragon family of materials almost two years ago, followed by Boston (B&L) and Optimum (Contamac), it's only recently that this technology has received widespread FDA approval. However, to maintain the advantages of the treatment, some patients will have to change their current lens care regimen.
Treatment and Benefits
First, let's define the treatment and discuss its benefits. The rigid contact lenses are placed in a vacuum chamber where low temperature ionized gases remove residual organic contaminants from the lens surface. This generates a more hydrophilic lens surface, enhancing initial wettability. Tests show that wetting angle measurements are indeed decreased after plasma treatment.
The treatment is available for new lenses only. This is when a lens needs it most, as most GP materials are inherently wettable. It's the residual oils, waxes and solvents from manufacturing that impede wettability. Plasma treatment has eliminated the need for pre-cleaning new non-plasmatreated GPs (for example, with an alcohol-based solvent such as the Boston Laboratory Cleaner, B&L). The process provides better initial comfort compared to non-treated lenses, which can benefit first-time GP lens wearers and patients who have histories of dry eye or excessive deposition.
Some labs treat all lenses of a certain design (such as Rose K, Blanchard), while others recommend it as a problem-solver.
Different Delivery System
It's important to know that the handling and care of these lenses is different. They are wet-shipped to maintain their hydrophilicity.
Bausch & Lomb materials are shipped with Boston Simplus Multi-Action Solution (B&L), and Contamac materials are shipped with Optimum (Lobob).
Both Paragon and Menicon Z materials are currently being shipped in Unique pH. Alcon discontinued that solution in summer 2007; Menicon Z will ship in Boston Simplus when supplies run out early next year.
For daily cleaning, B&L recommends Boston Simplus; Contamac, Optimum; and Menicon, Menicon GP (Menicon). Paragon has not made a final decision regarding its shipping or daily cleaning at press time.
Because the FDA has no regulations regarding post-plasma treatment lens care, any solution listed above can be used with any lens. However, surface polishing and the use of an abrasive daily cleaner (such as Boston Advance or Original) can negate the process and shouldn't be used.
Once the plasma treatment loses its effectivity, which is in approximately six months, patients may resume their previous lens care regimen with a separate abrasive daily cleaner, if needed.
Beneficial to Patients
With proper patient instructions regarding lens care, plasma treatment has proven beneficial to my practice and I recommend it for yours. CLS
To obtain references for this article, please visit http://www.clspectrum.com/references.asp and click on document #143.
Dr. Gromacki is a Diplomate in Cornea and Contact Lenses in the American Academy of Optometry. She has a specialty contact lens and post-surgical co-management practice as part of a multi-subspecialty ophthalmology group in Ann Arbor, MI.