Lasik Eyes Surgery - If you have concerns, wait as new refractive technologies are on the way...

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If you have concerns, wait as new refractive technologies are on the way...

Wizkid

2004-11-04, 10:10 pm

Ocular Surgery News....TOP STORIES 11/3/2004
Panel outlines new IOL technologies

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Robert H. Osher, MD, moderated a panel at AAO on emerging IOL
technologies.

NEW ORLEANS (AAO) — A panel of leading cataract surgeons discussed a
number of innovative IOLs currently in development during a symposium
called "Cataract Surgery: Living on the Edge" during the American
Academy of Ophthalmology meeting.

The rapid-fire session, organized and led by Robert H. Osher, MD,
included investigators' impressions of ultrathin lenses, adjustable
IOLs and other technologies on the horizon.

Dr. Osher noted that the ThinOptx Ultra Choice IOL has by now been
implanted in "thousands of eyes worldwide."

The ThinOptx lens is less than 0.5 mm thick at its thickest point and
can be rolled to fit through an incision of less than 2 mm. One face
of the 5.5-mm optic is divided into concentric zones, stepped in
height, with a different curvature on each step so that all light
traveling through the lens is focused at the same point on the retina.

The lens is in early stages of U.S. clinical trials, Dr. Osher said,
and the company is seeking funding.

An entirely diffractive phakic IOL, the VisionMembrane lens, is now in
clinical trials in Mexico, Dr. Osher said. This silicone lens with a
6-mm optic is less than 1 mm thick, he said.

Richard L. Lindstrom, MD, said diffractive optics may be "the way to
go" for phakic IOLs.

Richard L. Lindstrom, MD, one of the panel members at the session,
said diffractive optics "may be the way to go" for phakic IOLs. He
said with the limited space for a lens in the anterior chamber, the
thin profile that can be achieved with diffractive optics may be an
advantage over conventional refractive optics.

The Light Adjustable Lens (LAL) from Calhoun Vision has now begun
clinical trials outside the United States, Dr. Osher said. The
spherical and astigmatic power of this lens can be adjusted after
implantation with a special laser made by Zeiss.

Dr. Osher said that about 30 of these lenses have been implanted to
date. Twenty patients have undergone spherical adjustment of the lens,
he said, and 70% of those achieved a plano refraction. There have also
been toric adjustments in two patients with good results, he said.

The LALs implanted to date have been made of silicone. Samuel Masket,
MD, another panel member, said it is hoped the light-adjustable
concept can be carried over to acrylic materials.

I. Howard Fine, MD, also on the panel, said the full promise of the
technology will be serial adjustment. If the lens can be adjusted over
the course of the patient's life, it can be changed to refine its
accuracy or to adapt to different visual needs at different times, he
said.

Dr. Osher suggested that the adjustable lens technology may be
especially important for refractive lens exchange.

"If we're going to be tackling young patients who see well and who
have to pay a lot of money for a refractive surgical procedure, a
0.5-D error can be significant," he said.

Dr. Masket spoke about the SmartLens, in development by Medennium.
This lens, made from a hydrophilic acrylic material, is inserted into
the eye in the shape of a 1-mm-diameter rod, and it expands to fill
the capsular bag. Dr. Masket said the lens has been implanted in
cadaver eyes through a 2-mm incision and is currently undergoing
toxicology and other preclinical studies.

Panel members speculated that the ReStor lens, a
diffractive-refractive pseudoaccommodative IOL from Alcon, will be
available in the "very near future." (An Alcon official said in an
interview that U.S. regulatory approval of the ReStor is anticipated
in the first quarter of 2005.)

Dr. Lindstrom noted that Alcon had acquired the diffractive multifocal
IOL concept used by 3M in the 1980s and "clearly made it significantly
better." He and Dr. Osher, who were both investigators of the 3M lens,
said they thought the ReStor shows promise and has performed well in
clinical trials to date.

Another Alcon IOL, the Toric AcrySof, is "right behind ReStor in the
regulatory process," according to Stephen S. Lane, MD, another
panelist. He said the fact that the Toric and the ReStor are both
built on Alcon's AcrySof design raises the possibility that the two
elements can be combined in the future.

The panelists also discussed two IOLs currently available, the Alcon
AcrySof HOA and the Bausch & Lomb SofPort AO. The Alcon lens was
released earlier this year, and B&L lens was launched here at the AAO
meeting.

Both the new lenses have aspheric surfaces on one or both sides, and
both seem to have been inspired by the success of the Tecnis IOL from
Advanced Medical Optics, the panel members said. The Tecnis was
designed with a modified prolate anterior surface to correct for
negative asphericity in the human cornea.

The AcrySof HOA has its aspheric surface on the back of the IOL,
avoiding the need to make the edge of the lens thicker. The SofPort AO
has aspheric optics on both its front and back surfaces so that it
induces no spherical aberration.

"The idea that aspheric lenses provide superior vision is not a
surprise, based on experience with the Tecnis," Dr. Masket said.

Dr. Lindstrom said the SofPort AO lens "will be robust to decentration
and tilt."

Glenn - USAEyes.org

2004-11-04, 10:10 pm

That is, of couse, if one of these technologies is appropriate for the
individual patient's circumstances.

Glenn Hagele
Executive Director
Council for Refractive Surgery Quality Assurance

Email to glenn dot hagele at usaeyes dot org

http://www.USAEyes.org
http://www.ComplicatedEyes.org

I am not a doctor.