Contact Lens Practice Pearls
Managing Ocular Allergy in Contact Lens Wearers
By Gregory J. Nixon, OD, FAAO
Trees and grass and pollen—oh my! The blooming of spring is well underway for most of the United States by this time of year. While this is a welcome event for many of us who battled through a blustery, cold winter, it can mark the most challenging time of year for many contact lens wearers. Environmental allergy sufferers can exhibit ocular injection, chemosis, tearing, and itching (Palmares, 2010) that can prevent or compromise comfortable lens wear. While many of these symptoms cannot be completely eliminated, we can employ many strategies to minimize the impact of ocular allergies.
Contact Lens Strategies
An allergic reaction begins with the recognition of an allergic antigen or allergen coming into contact with the ocular surface (Figus, 2010). Because a contact lens can bind and harbor these allergens, it is advisable to have the most frequently replaced lens modality possible to minimize reintroducing an allergic stimulus on successive days of wear.
Single-use daily disposable lenses are ideal in this scenario, but they are limited in many toric and multifocal prescriptions. These patients often require a two-week or monthly replacement lens, so the lens material choice becomes important. As ionic lenses can exhibit increased protein deposition (Young, 1997), I utilize non-ionic lenses (FDA Groups 1 and 2) to minimize material surface binding.
The key to reducing allergic symptoms once they start is to limit the physiological effects of histamine and to control further histamine release from mast cells. Many of the newer-generation topical antihistamine agents work exceedingly well (Figus, 2010). The great benefit to contact lens wearers is that the newer prescription formulations have once-daily (Pataday [Alcon], Lastacaft [Allergan]) or twice-daily (Bepreve [Ista Pharmaceuticals], Elestat [Inspire Pharmaceuticals], Optivar [Meda Pharmaceuticals], Patanol [Alcon]) dosing. This allows patients to dose in the morning prior to lens application and then again after lens removal for the twice-daily formulations. Additionally, there are many over-the-counter formulations of ketotifen (Zaditor [Novartis], Alaway [Bausch + Lomb], Refresh Eye Itch Relief [Allergan], Claritin Eye drops [Schering-Plough], Zyrtec Itchy Eye drops [McNeil-PPC Inc.]) that serve as a viable alternative to prescription strength formulations.
The best management of allergies is to avoid contact with antigens (Buckley, 1998). This is not feasible for most patients, but the pharmaceuticals mentioned above can both reduce acute allergy symptoms after exposure and also help prevent the allergic response in the first place. For your allergy patients who predictably get symptomatic at the same time every year, simply prescribe them one of the new-generation antihistamines a few weeks in advance. These drops also stabilize mast cell membranes and prevent release of the inflammatory mediators that initiate the allergic inflammatory cascade (Figus, 2010).
If symptoms still persist, cold compresses are an underutilized technique to alleviate itching (Bielory, 2002). Also, preservative-free artificial tears (or those with disappearing preservatives) can help dilute the antigen concentration and flush away allergens (Bielory, 2002). CLS
For references, please visit www.clspectrum.com/references.asp and click on document #185.
Dr. Nixon is an associate professor of clinical optometry and the director of Extern Programs at The Ohio State University College of Optometry. He is also in a group private practice in Westerville, Ohio. He is on the Allergan Academic Advisory Board and the B+L Advisory Board. You can reach him at email@example.com.