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