Poor Near Vision Affects Even Lasik Patients As They Age. But They May Stay Glasses-Free With a New

December 10, 2005 Posted by The Sunday Times


Poor near vision affects even Lasik patients as they age. But they may stay glasses-free with a new treatment.
The big promise of Lasik surgery - that you could throw away your glasses and contacts - was only a half-truth, as maturing Lasik patients are starting to realise.
By middle age, virtually everyone develops presbyopia, the inability to read or focus close-up. So even former Lasik patients will have to look for a pair of reading glasses that will not make them look like grandparents.
Soon, however, there may be a way for them to remain free of glasses.

California company Refractec is studying whether conductive keratoplasty, a radio wave treatment for presbyopia, can be used on people who have had Lasik.
The idea is to pair the two treatments so people never have to wear contacts or glasses.
While Lasik uses a laser to reshape the cornea, conductive keratoplasty (Refractec calls its proprietary treatment NearVision CK) is performed using a probe - with a tip thinner than a strand of hair - that releases radio-frequency energy.
The radio waves are applied to the cornea in a circular pattern to gently shrink small areas of collagen. This creates a constrictive band that increases the curvature of the cornea, bringing near vision back into focus.
A preliminary study of 23 post-Lasik patients presented last month at the annual meeting of the American Academy of Ophthalmology in Chicago showed satisfactory results and no safety problems.
In the study, Dr Daniel Durrie, lead investigator and an ophthalmologist in Kansas City, found that 22 of the patients were able to read phonebook-sized print after CK, while maintaining good distance vision.
Eye doctors are eager to find options for ageing Lasik patients. More than four million Americans have had Lasik; according to Refractec, the average Lasik patient is 39.
NearVision CK was approved in 2002 for hyperopia, a condition that can occur in people of any age in which near vision is not clear. Last year, it was approved for the treatment of people whose only vision problem is age-related presbyopia.
The procedure has become the fastest-growing vision correction treatment since the introduction of Lasik in the mid-1990s.
"Most of us have been doing CK on post-Lasik patients for several years already. At present, it’s a legal and off-label use of the device," said Dr Marguerite McDonald, a clinical professor of ophthalmology at Tulane University School of Medicine in New Orleans. She served as an investigator of Lasik and was involved in earlier clinical trials for CK.
This combination of vision correction procedures will not be for everyone, however.
It works by producing monovision, meaning that one eye would be left as corrected by Lasik for distance, and the other would be corrected with CK to bring print and near objects into focus.
But this means the eyes cannot work together, and some people cannot adapt to having one eye blurred at all times.
Though CK is fast and is considered extremely safe, another potential drawback is that it must be repeated periodically, because the ageing eye’s lens continues to lose flexibility. This will cost about US$1,200 (S$2,020) to US$1,800 each time.
But future options for ageing eyes are likely to be improved. For example, research is under way on a new laser software program that will correct presbyopia in both eyes.
"We’re very close to a way to programme the laser so that our patients over 40 will be in focus at all distances with each eye," Dr McDonald said. "My guess is that this laser software will be approved in the within three years."—LAT-WP

Focus on CK

  Had Lasik to treat far vision but find that you have become long-sighted? To remain free of glasses, you can soon turn to conductive keratoplasty (CK).
  CK involves the use of radio waves on the cornea to bring the vision back into focus. It has been shown to correct near vision while maintaining good distance vision. 
  As it works by correcting one eye with CK and leaving the other eye as corrected by Lasik for distance viewing, some people may not be able to adapt to such monovision. CK patients also need repeat procedures every one to four years. 
  An option to treat long- sightedness is to have Lasik ‘enhancement’ in one eye that creates monovision. But there are risks, such as infection and dry eyes.
  CK has become the fastest-growing vision correction treatment since the introduction of Lasik in the mid-1990s. 


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