contact
lens care
How
Private-Label Solutions Affect Your Practice
BY
MICHAEL A. WARD, MMSC, FAAO
The contact lens industry continues to enjoy
steady growth (about 9 percent last year), largely as a result of technological
advances in lens materials and designs along with more comfortable and and
convenient lens care products. Unfortunately, a significant number of contact lens
patients drop out of lens wear each year because of discomfort that they often perceive
as dryness. Many of these 'dry eye' symptoms are in fact the manifestation of care
product/lens incompatibilities.
Solutions May Affect Comfort
Lens care product toxicities or care product/lens incompatibilities
can result in a compromised epithelial surface. We see this surface breakdown as
staining when we remove the contact lens and instill fluorescein. Such surface breakdown
(even sub-clinical epithelial disruptions) can cause dry eye-like symptoms, which
may lead to dropout. Further, any breakdown in the epithelium's barrier function
compromises this most important defense mechanism of the eye, creating portals of
entry for microbial invasion.
Manufacturers have formulated new multipurpose solution (MPS)
products to work with silicone hydrogel lens materials, which have surface chemistries
that differ from older-generation HEMA-based lenses. In addition to having a higher
modulus, silicone hydrogel materials have lower water contents but higher amounts
of bound water, lower levels of total protein uptake but higher binding of denatured
proteins, and a greater affinity for surface lipid uptake.
The latest generation MPS formulas provide better comfort,
wetting and lens/solution compatibility. All four major MPS brands are reformulated
to work with silicone hydrogel products. Private-label products are typically older-generation
versions that were formulated before silicone hydrogels entered the market.
Private-Label Differences
Private-label products accounted for greater than 30 percent of
disinfectant ounce sales in the first nine months of 2005 (A.C. Nielsen, September
2005). That percentage is larger than any single branded share.
Private-label solutions aren't really generic. Among pharmaceuticals,
a generic drug has the same formulation as the branded product. Private-label MPS
contact lens care products may contain different formulations under the same brand
name. As a hypothetical example, Big Store brand Dryz in April may be a two-generation-ago,
biguanide-preserved product, while the same blue and white bottle of Dryz in November
may contain a three-generation-ago, polyquaternium-pre- served product. It's the
same product name, box color, size and shape, so patients would reasonably assume
that it's the same product. The changing ingredients set the stage for possible
solution reactions.
Educate and Recommend
To avoid these complications, ensure that your patients are using
your recommended lens care products. New-generation MPS formulas are kinder and
gentler to the eye and are made to work with new-generation silicone hydrogel lens
materials. When patients resort to private-label solution use, they run the risk
of lens/solution incompatibilities. This may lead to dryness symptoms and dropout
— both of which are bad for the industry and bad for your practice.
Mr. Ward is an instructor
in ophthalmology at Emory University School of Medicine and Director, Emory Contact
Lens Service.
Contact Lens Spectrum, Issue: March 2006