contact lens care
The Latest Research in CL Care
BY SUSAN J. GROMACKI, OD, MS, FAAO

This year's meeting of the American Optometric Association featured 62 poster presentations. Fourteen of these projects involved contact lens or dry eye solutions. Following is a summary of the latest research in lens care:

• Tetronic 1304 gave excellent wettability for pHEMA-MAA lenses. Tetronic 1107 demonstrated low retention and, as a result, surface de-wetting after the early cycling stages. (Sponsored by Alcon)
• Bausch & Lomb's ReNu with MoistureLoc Multi-Purpose Solution prevented significantly more denatured lysozyme deposition compared with other no rub MPSs. (Bausch & Lomb)
• Complete Moisture Plus (AMO) and ReNu MultiPlus (Bausch & Lomb) caused no significant change in cellular integrity; Opti-Free Express (Alcon) proved cytotoxic to corneal epithelial cells. (AMO)
• The rewetting drop Clerz Plus (Alcon) proved compatible with silicone hydrogel contact lenses. (Alcon)
• Sodium hyaluronate is an effective demulcent ingredient in hydrogel contact lens rewetting drops. (AMO)
• KUptake of polyhexamethylene biguanide (PHMB) was as high as 7.2µg/lens, while polyquaternium-1 (PQ) uptake was below the detection limit of 1µg/lens for all seven materials tested. Combinations of lens materials with products containing 1ppm PHMB caused diffuse punctate staining for up to six hours; no significant staining showed up with the PQ-containing product for any lens material. (Alcon)
• A PMHB-based system may induce staining in the first hours after lens application, with no associated subjective symptoms. (Alcon)
• Over-simplified regimens are less effective than multi-step regimens. Opti-Free Express (PQ) displayed more microbial action than PHMB products (Complete, Solo-Care [CIBA Vision] and CyClean [Sauflon]). (Alcon)
• Studying the action of ReNu, Solo-Care, Clear Care (CIBA) and Opti-Free against yeast, ReNu was most effective and Solo-Care was least effective. (no sponsor)
• B&L's ReNu with Moisture-Loc Multi-Purpose Solution provides statistically significant longer-lasting wettability than Complete Multi-purpose Solution and Complete MoisturePlus. (Bausch & Lomb)
• Boston Simplus Multi-Action Solution (Bausch & Lomb) removed a higher percentage of deposits consisting of tear lipids, proteins and environmental components than Alcon's one-bottle system, Unique pH, and worked as well as Lobob's two-bottle system, Optimum. (Bausch & Lomb)
• Hypotonic MPSs may be beneficial in reducing contact lens-induced tear film hypertonicity and the subsequent cascade of dry eye and inflammation. The mean osmolarities: 225 Opti-Free Express, 256 Solo-Care, 261 ReNu and 303 Complete. (no sponsor)
• Comparing Systane (Alcon) to Refresh Tears (Allergan) over a 42-day period, the former decreased mean corneal and conjunctival staining and subjective frequency of dryness, scratchiness, grittiness and foreign body sensation. (Alcon)
• Patients using Systane before and after contact lens wear improved comfort and the lens-wearing experience. (Alcon)

What Do These Results Tell Us?

• Companies are actively studying, researching and developing their contact lens care products.
• Multipurpose contact lens solutions aren't all the same. Not only do they contain different active ingredients/preservatives, but they also offer different wetting/comfort agents and protein removers.
• Be cognizant of who sponsored the research. Research sponsored by industry will likely be published only if the results are positive for their particular product.

Dr. Gromacki is in group practice in Burke, Virginia, and has served as a faculty member at the University of Michigan Department of Ophthalmology and Visual Sciences.