SPECIAL ANNIVERSARY SECTION
- 20th anniversary
Lenses: The Good, the Bad and the Sad and Wasteful
HOLDEN, PHD, DSC, FAAO
The 1980s were an
epoch-making period for contact lenses: The first big U.S. push for extended wear
(EW); the goal-setting for hypoxia-free contact lenses; the investment in mass production
that would eventually underpin daily disposables; GP lenses that set a new standard
for safety and efficacy; multipurpose care systems that made heat, but not peroxide,
Unfortunately the EW push was premature and it was another decade
before manufacturers developed hypoxia-free soft lenses to give the modality a real
chance. But the specter of infections continues to shadow the field.
The late '80s and early '90s saw the development of consistent,
well-made, molded and physically comfortable soft contact lenses.
Nowhere was this more noticeable than in soft toric lenses. No
longer would we hand down the dreadful judgement to a distraught patient that "we
can't fit you with contact lenses because you're an astigmat." It was a triumph
for design and engineering.
Except engineering often cannot overcome one lingering physical
challenge a beautifully round, hospitable edge, an edge for all lenses for
all tissues. Few if any manufacturers have mastered this critical parameter. Other
challenges remaining for the industry include mastery of wettability and creating
an inhospitable surface to invaders.
Infections and Lawsuits
But one challenge overrides them all eliminating infections.
Infections dog our industry, and we can't but wonder what might have happened if
our industry had taken the money spent on lawsuits and applied it to achieving a
100-fold reduction in the risk of MK. Instead we hear: "Stop talking about MK, it
will harm the business."
Fair enough, patent disputes on billion dollar products are part
of the system, but advertising disputes costing millions apparently often
used as an obstacle strategy what a waste! The fact (a la Holden) is that
it's the level of oxygen behind the contact lens that counts. If you have air-levels
of oxygen behind the lens, you're ready for lens wear challenges.
But back to infections we have to decimate them. They
occur five times more frequently if you sleep in lenses, maybe slightly less and
less severe with high-Dk soft lenses and even less with GPs, but still too many.
They occur with overnight ortho-k, but probably no more frequently than with any
other overnight lens.
Manufacturers and practitioners need to work together. Give patients
explicit, colorful, concise, memorable warnings of what to do and not to do. Develop
anti-bacterial surfaces, cases and solutions. Bring back rubbing and rinsing. Research
the causes with a really serious investment and a dogged determination to win.
Advice for the Future
We have a great industry with some really great people. We have
triumphs like hypoxia-free silicone hydrogels (the ones with 125+ Dk/t) and GPs,
daily disposables, torics that work, emerging comfort technologies, the hope of
silicone–like pediatric lenses, good keratoconus lenses and 120 million wearers.
Round the edges, make everything anti-bacterial, provide tear
film simulated wettability, develop a really good bifocal (they are getting better),
stop wasting our time with the 'yes-it-is-no-it-isn't' lawsuits, put a brake on
myopia and stop milking the lens care business, and invest together in solving the
microbial challenges and we could have a billion wearers. Was that a pig
I saw fly past the window?
Dr. Holden, is Scientia
Professor of Optometry, founder and director of the Cornea and Contact Lens Research
Unit, Deputy CEO of the Vision Cooperative Research Centre and CEO of the Institute
for Eye Research in Sydney, Australia, at the University of New South Wales.
Contact Lens Spectrum, Issue: June 2006