CONTACT LENSES TODAY
April 17, 2005
Contact Lenses Today® is edited by Dr. Joseph T. Barr and the staff of Contact Lens Spectrum. This
week CLToday® reaches more than 10,000 readers in 74 countries.
AMD Risk Doubled from Smoking
A recent study proves that people who smoke have double the risk of suffering from age-related macular
degeneration (AMD) as those who didn't. Researchers questioned people in the study about their smoking habits, alcohol consumption and
cardiovascular disease. They reported their findings in the British Journal of Ophthalmology. People who stopped smoking more
than 20 years earlier had no increased risk developing the illness. Based on the findings, the researchers estimate that smoking is
likely to have been linked to up to 30,000 cases of the disease in Britain.
B&L Offers Online Toric Calculator
Bausch & Lomb is introducing a new, free online resource designed to further streamline the already simplified
process of fitting astigmatic patients with Bausch & Lomb SofLens66 Toric contact lenses. According to B&L, the speed and accuracy with which
the online toric calculator delivers results are designed to improve office efficiency and reduce chair time for astigmatic patients.
ASCRT Approaching Fast
The 2005 Annual Meeting of the American Society of Corneal and Refractive Technologies (ASCRT) will be held in
Scottsdale, Arizona this year from May 13 to May 15. This year's faculty includes Joseph T. Barr, O.D.; Marc R. Bloomenstein, O.D., F.A.A.O.;
Patrick Caroline, C.O.T., F.C.L.S.A., F.A.A.O.; Craig Norman, F.C.L.S.A.; Marjorie Rah, O.D., Ph.D.; Jeffrey Walline, O.D., Ph.D., F.A.A.O.; and
others. With its emphasis on current and developing corneal refractive technologies, the ASCRT was set into motion in 2004 with the mission of
providing advocacy and a forum for the discussion and development of these technologies.
Dk/t -- How Much Oxygen is Really Enough?
Today, there is much being said about Dk/t and much debate about whether or not more oxygen really is better. You may be surprised to
learn that all available silicone hydrogel contact lenses provide essentially the same levels of oxygen to the cornea. ACUVUE ADVANCE Brand Contact
Lenses with HYDRACLEAR, for example, have a Dk/t level of 86 and provide 97% of all the oxygen that would be available if you weren't wearing lenses
at all. By doubling this Dk/t number, the cornea only receives an additional 2% of
oxygen.
http://www.ecp.acuvue.com
--ADVERTISING
Menicon Z to be Sold in China
Menicon recently announced that the State Food & Drug Administration approved the Menicon Z lens to be sold in China.
The company expects to launch the lens in the Chinese market in June 2005.
FDA Approves Retisert
The FDA has approved Bausch & Lomb's single-indication orphan drug Retisert (fluocinolone acetonide intravitreal implant)
0.59mg for the treatment of chronic non-infectious uveitis affecting the posterior segment of the eye. The company's patented drug-delivery
microtechnology in Retisert consists of a tiny drug reservoir designed to deliver sustained levels of fluocinolone acetonide for approximately
two-and-a-half years directly to the back of the eye. B&L manufactures Retisert at its new pharmaceutical facility in Waterford, Ireland and is
targeting a mid-year launch of the product.
Abstract:
Hope for Treating Amblyopia in Older Children
Researchers provided 507 amblyopic patients (aged seven to 17 years) who had visual acuity ranging from 20/40 to
20/400 with optimal optical correction and then randomized the subjects (at 49 clinical sites) to a treatment group (two to six hours each day of
prescribed patching combined with near visual acuities for all patients plus atropine sulfate for children aged seven to 12 years) or an optical
correction group (optical correction alone). The researchers concluded that amblyopia improves with optical correction alone in about one-fourth
of patients aged seven to 17 years, although most patients who are initially treated with optical correction alone will require additional treatment
for amblyopia. For patients aged seven to 12 years, prescribing two to six hours each day of patching with near visual activities and atropine can
improve visual acuity even if the amblyopia has been previously treated. For patients aged 13 to 17 years, prescribing patching two to six hours
each day with near visual activities may improve visual acuity when amblyopia hasn't been previously treated, but appears to be of little benefit
if amblyopia
was previously treated with patching. The researchers don't know whether visual
acuity improvement will be sustained once treatment is discontinued.
The
Writing Committee for the Pediatric Eye Disease Investigator Group. Randomized Trial of Treatment of Amblyopia in Children Aged 7 to 17
Years. Archives of Ophthalmology 2005 April;123:437-447.
Editor's Commentary:
GP Advice
This past week, the GP Lens Institute (GPLI, http://www.rgpli.org), sponsored
by CLMA, had an online chat regarding irregular corneal fitting. Ed Bennett moderated and I was the so-called "expert" for the evening. There
was some good advice:
For keratoconus allergy sufferers, pre and post wear topical antihistamine/mast cell stabilizers or NSAIDs are helpful.
A small GP lens may work just fine for Pellucid Marginal Degeneration. Use the highest Dk, most stable and wettable GP material you and your GP
laboratory agreed on. Don't be afraid to try larger GP lens designs when normal lens designs fail and start with larger lenses on PK patients.
Look at the GLPI Web site for more information on GP lens use.
Fitting Tip:
Before You Give up on Monovision
Here's one I thought of when recently examining a 46-year-old patient:
We must be careful when taking our mindsets
on exactness of refractions for our pre-40 patients and using the same mindset on our monovision patients. Quite often, we will give spherical lenses
OU when one is near or exactly spherical and the other eye has .75 cylinder. The OU result is good for the patient, easy to accomplish and the patient
loves not paying for the higher-priced toric. Just be careful when that patient reaches early-to-mid presbyopic levels. That patient who for many years
handled masked astigmatism well and had good vision OU now may have minor subjective complaints. You won't get that extra notch of better vision OU as
easily with monovision. We all know that one eye must handle distance tasks and the other must handle near tasks. The eye that has .75 cylinder may now
require a toric to maximize visual performance either at distance or at near because that "additive effect of OU" has been decreased. Try torics that
were previously not necessary before you give up and say that monovision has failed.
--Mark Greenwell, O.D.
Papillion,
Nebr.
Make Room for the Global Orthokeratology Symposium (GOS) this Summer
(July 28 to 31, 2005 in Chicago, Ill. -- for the first time in the U.S.A.)
The only worldwide meeting focused solely on
orthokeratology/corneal reshaping. Register by April 30, 2005 to save $115 off the full symposium price.
--ADVERTISING
This month at http://www.siliconehydrogels.org, consider the potential
of silicone hydrogels for patients who have irregular astigmatism, compare subjective and objective means of measuring corneal staining, review the
features that increase a solution's compatibility with silicone hydrogel materials and read the results of a study evaluating the cytotoxic potential
of various solutions.
Report adverse contact lens reactions
here: http://www.accessdata.fda.gov/scripts/medwatch/ or call
(800) FDA-1088.
Access a reporting form for complications you've seen that were a result of contact lenses dispensed
without a valid prescription at the Association of Regulatory Boards of Optometry's (ARBO's) Web
site: http://www.arbo.org/arbo.asp?dt=R&doc=Complications. Complete and send the
form online or print it out and fax it to (866) 886-6164.
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to tips@cltoday.com -- if your tip is selected as 'Best of the Month,' you'll receive a free golf
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