By Jeanie Lerche Davis
Reviewed By Brunilda Nazario
Like death and taxes, presbyopia happens.
The word means "aging eyes." Some call it short-arm syndrome. It's the inability to focus on objects that are near, and it's another sign you're over 40 and will need reading glasses or bifocals. But unlike Aunt Hazel and Uncle Bob, you've got options. No drugstore granny glasses for you.
What Nike and Reebok did for running shoes, contact lens manufacturers are doing for you. It's not yet available everywhere, but it will be.
What's going on? Starting in your 30s, doctors believe that the eye's lens starts to become less flexible. When muscles in the eye try to focus on close objects, the lens can't respond as well. By 40 or 45, you're beginning to experience difficulty with your vision, blurring of objects that are near.
Bifocal means two points of focus. Eyeglasses can come with bifocal corrections on them.
Bifocal contact lens are also available. They've been around for a few years, but not everyone likes them. Close vision just hasn't been good. The pupil is the problem: as it dilates and contracts to allow light in, vision changes. Contact lenses haven't been able to accommodate those tiny little adjustments.
However, new "wave-front sensing" technology is making bifocal contacts more wearable than before. "The technology has allowed us to actually plot the pupil size," explains Jonathan D. Carr, MD, professor of ophthalmology at Emory University School of Medicine. Carr is also a refractive surgeon at Emory Vision, both in Atlanta.
"That's a constantly improving field," Carr tells WebMD. "This technology allows us to capture the imperfect wave that leaves every human eye."
When this pupil data is factored into the manufacture of bifocal contact lenses, a custom-made bifocal lens is created. "It's like what Nike and Reebok did for running shoes," says Carr. "Certain contact lens centers are working with manufacturers so more people can tolerate bifocal contact lenses."
Also, newer-generation silicone hydrogel lenses have "significantly less" risk of infection than previous extended-wear lenses, says Gregg Russell, OD, a private-practice optometrist in Edonton, Ga., southeast of Atanta.
The new gels also offer greater comfort. "The biggest problem is that contact lenses dry out," Russell tells WebMD. "By the end of the day, people have poor vision, their eyes are red, itchy. The newer materials don't dry out nearly as badly. They provide much more comfortable vision from morning to night."
No-Hands Contact Lenses
Why not an implanted "contact lens?"
In fact, it's being developed -- based on cataract surgery, which was perfected some 30 years ago. During the cataract procedure, the surgeon goes in through the pupil and removes the lens from the eye, replacing it with a clear lens implant. The procedure is tried-and-true, even routine.
The idea of a lens implant is "very important because it allows baby boomers, when they get into cataract age, to have a [corrected] lens implanted in the eye and they won't need glasses," Carr tells WebMD.
Guy E. Knolle Jr., MD, a private-practice ophthalmologist in Austin, Texas, has a bigger vision. "The good candidate is just about anybody who really wants to see better," he tells WebMD.
In fact, the procedure is what he calls a "clear lensectomy" -- removing the clear lens and replacing it with a multifocal intraocular lens. It is also an off-label use for the Array lens, which got FDA approval in 1997 for cataract surgery, Knolle says.
However, insurance covers this procedure only if you have cataracts, he says.
The best candidates for lens implant surgery are:
- People with both myopia and presbyopia -- but nothing extreme. "They can't see good up close or at a distance without their glasses," says Knolle
- Those with presbyopia only
With severe myopia, there's greater chance of retinal detachment -- although that can be corrected in surgery before the implant. "It's still a controlled, calculated risk, because the success rate is very high," Knolle says.
Knolle's had it done. "I hated my glasses," he tells WebMD. "I didn't start wearing them until I was 45. After listening to patients tell me how good their vision was, it just didn't make sense not to have it. I had a friend do the surgery on me. I've been very happy with my vision."
As fascinating as lens implants sound, don't discount LASIK. In fact, lasers have come a long way in the last 20 years, when they broke in to corneal surgery, says Carr.
Today's pinpoint lasers are like "small artists' brushes," he tells WebMD. "They allow us to do more meticulous work."
Plus, researchers are gaining a better understanding of how the cornea heals after a laser touches it -- and how, in time, that alters the vision correction. "Knowing how your cornea heals is very important in giving your cornea a very sophisticated shape, giving you a progressive lens," Carr explains.
"With knowledge of corneal healing -- and with wave-front technology to capture the imperfect wave that leaves every human eye -- we're in a very strong position," he says. "I'm not going to suggest that it's going to be 10 years, it's going to unfold over the next one to three years."
Also, two versions of LASIK for presbyopia -- called laser thermoplasty and conductive keratoplasty -- have been FDA approved for temporary reduction of low-level farsightedness, says Carr. However, many people lose up to 50% of their vision correction in the first year. Also, the procedures have not been tested for safety and effectiveness if they are repeated.
But right now, patients with presbyopia and myopia will likely get "monovision" -- the dominant eye gets LASIK correction for distant vision, and the other is corrected for close vision. Most people can make it work, doctors say. If they don't like it, both eyes will be corrected for distant vision, and they can use reading glasses. "It's an excellent option," says Carr.
As far as presbyopia, here's Carr's advice: "There's always measurable risk with any procedure, so you need to be cautious. But the technology today has allowed us to get past much of the caution we used to advise."
Published Oct. 13, 2003.
SOURCES: Jonathan D. Carr, MD, professor of ophthalmology, Emory University School of Medicine, Atlanta. Guy E. Knolle, Jr., MD, private-practice ophthalmologist, Austin, Texas.
©1996-2005 WebMD Inc. All rights reserved.