- The Washington Times - Monday, May 28, 2007

Dr. John O’Neill Sr., a pediatric ophthalmologist in his 70s, figured a cataract was the cause of blurred and diminishing vision in his left eye.

Dr. O’Neill and Dr. Thomas Clinch, his associate at Eye Doctors of Washington in Chevy Chase and Northwest, discussed his options before deciding on a multifocal lens to replace the cataract, a lens that is cloudy and distorts light passing through the eye. The artificial lens, which was implanted in January 2006, provided him with near, intermediate and far-focusing power.

Alternatively, a conventional or traditional monofocal lens would have corrected Dr. O’Neill’s vision for one distance and required him to use reading or eyeglasses for the other distances.

“This has made a great difference for me to be able to do many things without glasses,” Dr. O’Neill says. “It switches your eyes back to what they were when they were much younger.”

Artificial lenses surgically implanted into the eye are used to help correct cataracts, presbyopia, which is the loss of the eye’s ability to change focus, and other vision problems.

Intraocular lenses (IOLs), a type of artificial lens, replace the crystalline lens of the eye after a cataract is removed or are used to help correct presbyopia, says Dr. Clinch, a consultant in cornea, cataract and refractive surgery for Eye Doctors of America. Phakic intraocular lenses are implanted on top of the eye’s existing lens to correct more severe levels of nearsightedness that are outside the prescription range for laser vision correction, he says. Laser vision correction, he explains, changes the shape of the front surface of the cornea.

“These lenses leave the cornea alone and are inserted into the eye,” Dr. Clinch says.

Implantable contact lenses are used to correct moderate to severe refractive disorders, including nearsightedness, farsightedness and astigmatism, says Darcy Wendel, vice president of marketing for Staar Surgical Co., a manufacturer of IOLs and implantable contact lenses based in Monrovia, Calif.

“The lens is invisible,” Mrs. Wendel says. “Another advantage is the visual recovery is immediate. You’re going to see well right now.”

Each human eye has two lenses, the crystalline or natural lens, and the cornea or the surface lens of the eye, says Dr. Maxwell Helfgott, chairman of the ophthalmology department at Washington Hospital Center in Northwest. He is president of the Washington National Eye Center, an incorporated nonprofit organization that contracts with Washington Hospital Center.

The crystalline lens changes focus from distance to near focal points, but beginning at age 40 to 45, it can stiffen and harden into a cataract and lose focusing ability, Dr. Helfgott says. Cataracts, which happen to most of the population as a result of the aging process, require bifocals, reading glasses or surgery to accommodate the near focus.

“Cataracts is the most preventable form of blindness worldwide,” says John Siccone, spokesman for the American Society of Cataract and Refractive Surgery (ASCRS), a medial specialty society in Fairfax.

Last year, 2.7 million cataract surgeries were performed in the United States, Mr. Siccone says.

“That number will go up as the population ages,” he says.

Another aging condition, presbyopia, causes a loss of focusing power when the eye switches from one distance to another, such as changing from reading up close to looking into the distance, Dr. Helfgott says.

“It’s the normal loss of elasticity of the natural lens that almost everyone starts to develop in their 40s that makes reading difficult,” says Dr. Jay Lustbader, chairman of the Department of Ophthalmology at Georgetown University Hospital in Northwest.

IOLs, which since the late 1960s or early 1970s replaced cataracts, were improved over the past two to three years to accommodate other vision problems, Dr. Helfgott says.

The original monofocal or single-vision IOLs only helped with distance vision, Dr. Helfgott says.

“That monofocal, single-vision implant gives you great vision, but it can’t change focus, because it’s not flexible,” he says.

Alternatively, multifocal IOLs — used to correct both cataracts and presbyopia — have concentric rings of varying optical powers to provide a full range of far and near focus, says Dr. David F. Chang, member of ASCRS and the American Academy of Ophthalmology, a membership organization in San Francisco. He is a professor of ophthalmology at the University of California in San Francisco.

“Compared to a single-focus lens implant set for distance focus only, a multifocal lens improves your ability to see up close without glasses,” Dr. Chang says. “The brain automatically finds the correct focus.”

Another type of multirange IOL, the accommodating lens, imitates the flexibility of the eye’s natural lens by moving back and forth and forward and backward to change focus, Dr. Lustbader says.

“In my experience, the results were quite variable with some patients having some ability to read while others had no long-term effect,” Dr. Clinch says. “It’s implanted less frequently by surgeons than the multifocal lenses now available.”

Phakic IOLs, which do not require the natural lens to be removed, bend the light entering the eye and focus it on the retina, says Russ Trenary, executive vice president of Advanced Medical Optics, a designer and manufacturer of IOLs headquartered in Santa Ana, Calif. He is president of AMO’s cataract refractive surgery group.

“That lens is for patients who don’t have cataracts. They typically are so myopic or nearsighted, even glasses or contacts don’t give them the vision they want,” Mr. Trenary says.

Patients with severe myopia usually do not have enough corneal surface for laser correction, Dr. Clinch says.

“You don’t want to thin the cornea too much because that can create instability, and you don’t want to flatten it too much because it could lead to visual disturbances like glare and halos,” he says. “The beauty of phakic intraocular lenses is that they don’t change the corneal shape.”

The notion that eyeglasses or reading glasses can be thrown away after eye surgery is rarely achieved, Dr. Helfgott says.

“We’re dealing with tissues, not plastic. Everything is not perfect,” he says. “But all of these procedures are improving and are continuing to improve.”

“The [implantable contact] lens is invisible. Another advantage is the visual recovery is immediate. You’re going to see well right now.”

—Darcy Wendel, vice president of marketing for Staar Surgical Co.

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