Cornea Inlay Improves Near Vision in People With Presbyopia
By Charlene Laino
WebMD Health News
Reviewed by Laura J. Martin, MD
Latest Eyesight News
Oct. 24, 2011 (Orlando, Fla.) -- A Lifesaver-shaped micro-disc about the size of a pinpoint can help restore normal reading vision in the millions of baby boomers who have trouble making out newspaper print, cell phone text messages, and other small print, researchers say.
In a study, the Kamra cornea inlay improved near vision in all of about 2,000 people with presbyopia, says Minoru Tomita, MD, PhD, executive director of the Shinagawa LASIK Center in Tokyo.
He presented the findings here at the annual meeting of the American Academy of Ophthalmology.
Presbyopia refers to the gradual loss of the eye's ability to focus, making it difficult to see objects up close. It's a natural, albeit annoying, part of the aging process that most people begin to notice in their 40s.
The Kamra corneal inlay is designed to restore near vision without affecting distance vision. It does so by taking advantage of the "pinhole effect," which blocks peripheral rays and only allows focused light to reach the retina. (You can try this at home: Just roll up a piece of paper to create a pinhole-sized opening at one end and a larger opening at the other, and look through it.)
The inlay weighs less than a grain of salt and patients will not feel it, Tomita tells WebMD.
During the 15- to 20-minute procedure, the same type of laser employed in LASIK eye surgery is used to create a flap in the non-dominant eye. The inlay is placed on the cornea layer and centered over the pupil, and the flap is repositioned.
For people who have trouble seeing objects that are far away, simultaneous LASIK laser eye surgery can be used to restore distance vision.
The inlay is not available in the U.S., although maker AcuFocus hopes to gain FDA approval next year. It is available in Europe, Asia, and South America.
The cornea inlay costs about $5,000 to $7,000, "about the same as LASIK," Tomita says.
The new study, funded by AcuFocus, involved people in their 40s, 50s, and 60s who had problems with near and distance vision. LASIK was performed to correct distance vision, and the microscopic ring was implanted to correct near vision.
Of the approximately 450 people who have been followed for six months to date:
- Those in their 40s could read four additional lines on a 13- to 15-line eye chart, on average. People in their 50s could read five more lines, and those in their 60s could read seven additional lines.
"Basically, they could only read headlines before the procedure," says AAO spokesman James Salz, MD, clinical professor of ophthalmology at the University of Southern California in Los Angeles.
"Afterward, they could read most things, except the very small print on a medicine bottle," he says. Salz reviewed the results for WebMD.
- About 90% of people in all three age groups said they were satisfied or very satisfied with the results.
- About 95% said they were less dependent on reading glasses.
- Long distance vision was 20/20 or better in people in all age groups.
Tomita says the most common side effect was dry eye, which affected about 10% of patients and was treatable.
In general, the most common side effects include ocular surface changes, glare, halos, and night vision disturbances, according to AcuFocus' web site. Over time, these conditions are expected to lessen or go away.
Salz tells WebMD that he's generally impressed with the inlay. "It's very safe and reversible. If we put it in and you don't like it, we can take it out," he says.
Salz notes that some people with presbyopia opt for LASIK to deliberately under-correct one eye to let them see close objects, even though it's at the slight expense of distance vision.
"This inlay changes focus so you can read and it doesn't affect distance," he says.
But "this doesn't mean you will never need glasses," Salz says. "It's primarily for what I call social vision -- taking a quick look at a menu, at the GPS in the car, and so on," he says.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
SOURCES: 115th Annual Meeting of the American Academy of Ophthalmology, Orlando, Fla., Oct. 23-25, 2011.Minoru Tomita, MD, PhD, executive director, Shinagawa LASIK Center, Tokyo.James Salz, MD, clinical professor of ophthalmology, University of Southern California, Los Angeles. ©2011 WebMD, LLC. All Rights Reserved.
Subscribe to MedicineNet's General Health Newsletter