Artificial lens can correct vision of cataract patients

Published: November 28, 2005 | 2855th good news item since 2003

A new procedure for cataract patients can allow them to be free of contacts or glasses. [The Cataract Cure : The Russian eye-drop breakthrough: The story of N-acetylcarnosine]

The key is a replacement lens approved in April by the Food and Drug Administration, Dr. Steven Sicher, an ophthalmologist with Illinois Eye Center, said.

“It’s made with better technologies. During the studies, the results have been encouraging. And it’s now just being released for more widespread use,” Sicher said.

According to Alcon, a manufacturer of ophthalmic pharmaceutical, surgical and vision care products, 80 percent of patients in a clinical trial reported never using reading glasses or bifocals following bilateral cataract surgery with Restor lens.

Cataracts cloud the lens inside the eye and in 90 percent of cases are caused by aging. Patients can experience blurred images and reduced low light vision, even with bifocals or reading glasses.

REPLACEMENT BEST

The best way to treat a cataract is to replace the old lens with an artificial lens, Sicher said. The new lens corrects the vision at the same time. Depending on a person’s insurance coverage, the procedure can cost about $1,500 per eye, out of pocket.

LASIK surgery, an almost decade-old procedure, uses a laser to reshape the cornea. It can cost $1,675 per eye. [LASIK: A Guide to Laser Vision Correction]

People apprehensive about going under the laser can choose corneal refractive therapy.

Patients wear gas permeable contact lenses while they sleep and the contacts mold and flatten the cornea, said Dr. Robin Wilson, an Illinois optometrist. “They create a plateau on the surface of the cornea. The rigid material accommodates for tear flow,” Wilson said.

The amount of hours people can see during the day depends on their prescription. A higher prescription is more likely to allow fewer hours of vision.

“It depends on the person, but usually people can see for 12 to 16 hours in the day,” Wilson said.

CRT, which can cost $1,100 to $1,400 for lenses and fitting, is similar to LASIK surgery in terms of reshaping the cornea. LASIK patients have the possibility of slipping back into poor eyesight, but it’s rare. CRT’s effects are only temporary and the patient must continue wearing the lenses.

NO RISK

“It’s a middle ground for surgery. There’s really no risk,” Wilson said.

However, not everyone is a candidate for CRT. People with too high a prescription or high astigmatism usually have unfavorable results.

Some patients may be irritated by overnight contact use. Some people may simply opt for a more comfortable pair of contact lenses. A new extended-wear silicone hydrogel contact lens that allows longer usage and less irritation was approved by the FDA earlier this year, said Dr. Krey Bixby, an Illinois optometrist.

OXYGEN FLOW

The lenses allow more oxygen to pass through to the eye, which helps in preventing corneal ulcers. Corneal ulcers occur when contacts prevent the eye from receiving oxygen needed to break down bacteria that sticks to the eye surface. The new lenses have also improved in hydration to prevent dry, irritated eyes.

“The old hydrogel lenses started out with 60 percent water. And you can think of them like a sponge. So it was 60 percent water, 30 percent plastic. At the end of the day it was down to 30 percent water,” said Bixby. “And if you compare that to the kitchen sponge you lay on the counter, at the end of the day the sponge is dry and rough.”

Bixby said the new lenses have zero dehydration by the end of the day.

Published in Science & Technology
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