Contact Lens Care & Compliance
A Lens Care Summit Overview
By Susan J. Gromacki, OD, MS, FAAO
The Global Contact Lens Care Summit took place in Seattle in November. The meeting, dedicated entirely to lens care, was sponsored by Bausch + Lomb (B +L). Participants were industry representatives, U.S. Food and Drug Administration (FDA) staff and scientists, and clinicians.
The meeting was divided into five topics: history, evolution, and evolving standards of lens care; care and ocular surface homeostasis; ocular surface health with lens wear; contemporary research in lens care; and implications for the clinical practice.
On history, Dr. Ralph Stone (retired Alcon), an originator of lens material classification, recalled the days when a solution's packaging listed every lens tested with it. Of course, there were only two soft lens materials in 1972; this increased to 37 in 1994 and to 90 today, as well as 66 GP materials. Given all of the advances, he stated that half of all lens wearers still drop out due to discomfort.
Dr. Lynn Winterton (Alcon), speaking on the interaction of solution with material, said, “The surface is the problem source of everything we do.” He cautioned that surface angle measurements do not necessarily tell us about compatibility of a material, but rather the surface environment.
Dr. Oliver Schein, author of two commonly referenced papers on infectious keratitis, argued that improving solution technology will not reduce lens infection rates because of biofilm, patient noncompliance, and poor case care. Dr. Joe Barr (B +L) disagreed, saying that with improved solution technology, industry regulations, and patient compliance, infections can be reduced.
Dr. Noel Brennan stated that Holden and Mertz's corneal swelling measurements have been updated and that silicone hydrogel materials—not yet invented at the time of the research—do not fit on a best-fit line of their graph. He said, “There is no true Dk/t to avoid corneal swelling.”
To prevent contact lens-related infection, Dr. Suzanne Fleiszig instructed: 1. protect the corneal defenses (epithelium, basal lamina, and tear fluid) and 2. prevent bacterial virulence.
Dr. Mark Willcox relayed that microbes adhere more to silicone hydrogel than to traditional soft lens materials and to ridged cases more than to smooth. He also noted that silver-impregnated cases do reduce contamination.
In a debate, Dr. Frank Bright argued that transient solution-induced corneal staining (SICS) was caused by sodium fluorescein binding to the solution preservative polyhexamethylene biguanide. Dr. Lyndon Jones stated that NaFl does enter epithelial cells because SICS doesn't occur in all patients and is not evenly distributed throughout the cornea. In addition, confocal microscopy illustrates that cells can take up NaFl.
Dr. Curtis Dobson described his research, which found that the antimicrobial properties of tear proteins are still present when isolated from contact lenses. Regarding corneal infiltrates, Dr. Robin Chalmers reported that younger patients are at higher risk and that older patients do better at hand washing and lens cleaning.
FDA scientist Dr. Joe Hutter described some of the FDA's latest research. He stated that as lenses absorb preservatives, they decrease the efficacy of the solution; and that each material and solution absorbs differently.
Lastly, Alan Saks gave a practical summary on how to decrease lens deposition and contamination: prescribe daily disposables; minimize digital contact with lenses, particularly the inside of the lenses; avoid moisturized and pump soaps; provide both verbal and written instructions; and lastly, take charge of patients' lens care education.
More About the Meeting
A comprehensive meeting summary will be published via a peer-reviewed manuscript in Contact Lens and Anterior Eye. CLS
|Dr. Gromacki is a diplomate in the American Academy of Optometry's Section on Cornea, Contact Lenses and Refractive Technologies. She is chief research optometrist at Keller Community Hospital in West Point, N.Y.|