Article Date: 7/1/2006

discovering dry eye
Update from The 2006 Annual BCLA Conference
BY JASON J. NICHOLS, OD, MPH, PHD

This year's British Contact Lens Association's annual conference in Birmingham, England was similar to last year's: The proceedings were spectacular. The conference opened with Drs. Brien Holden and Dwight Cavanagh discussing orthokeratology. There is still considerable debate about the procedure's safety, especially as it relates to microbial keratitis cases over the last few years.

Patient Comfort

There was also an emphasis this year on improving patient comfort, especially as it relates to lens care solutions, new materials and our understanding of the contact lens/tear film interaction.

Professor Charles McMonnies, in his lecture "Measuring and Optimizing Patient Comfort," discussed factors that can impact comfort, including the contact lens (material and design, on-eye compatibility); tear film and ocular surface (tear quality, ocular surface integrity); psychological factors (patient motivation, mood, expectations); and external factors (ambient conditions, visual task conditions, computer usage). He emphasized that we not forget about new technologies that can help bring previous lens wearers back into lenses.

Ocular Surface

Dr. Noel Brennan of Brennan Consultants lectured on an important and often neglected ocular surface component relating to comfortable and safe contact lens wear, "Conjunctiva...the forgotten tissue."

Dr. Brennan suggested that it's vitally important to assess the conjunctiva of silicone hydrogel lens wearers via fluorescein and lissamine green relative to "conjunctival splits and fringes" that have recently been identified with silicone hydrogel lens wear. He also discussed the resurgence of contact lens-related papillary conjunctivitis with silicone hydrogels — something now seen "locally" on the palpebral conjunctival tissue vs. a more general inflammation of the conjunctiva. This may be related to the stiffness of some of the silicone hydrogel materials.

Dr. Eric Papas of the Vision Cooperative Research Center in Sydney, Australia presented the results of a large meta-analysis including 596 soft lens daily wear participants to examine the relation between "toxic" corneal staining and corneal infiltrates. Subjects who were experiencing "toxic" corneal staining were four times more likely to also present with a corneal infiltrate than were those without such staining, confirming what practitioners commonly observe.

New Materials

Several presentations discussed how new materials were associated with improved patient comfort. Dr. Graeme Young and coworkers (Visioncare Research Ltd.) presented results showing improved overall patient comfort and comfortable wearing time when "problem" patients were refit with a new silicone hydrogel lens (Acuvue Oasys, Vistakon). Other research presented showed improved comfort with CooperVision's new silicone hydrogel lens (Biofinity), and with novel materials that incorporate polyvinyl alcohol and polyvinyl pyrolidone intended to attract and maintain water.

Lens Care Solutions

Finally, several studies were presented that show contact lens care solutions can have a substantial impact on patient comfort in contact lenses. Care solutions with targeted surface active agents seem to aid in promoting a more wettable surface via contact angle measures. The relation of these ex-vivo contact angle measures to the in-vivo (on-eye) situation with the lens/tear film interaction is still not understood.

Dr. Nichols is assistant professor of optometry and vision science at The Ohio State University College of Optometry.



Contact Lens Spectrum, Issue: July 2006