Laser Presbyopia Reversal (LAPR)
Presbyopia, the age-related loss of near vision that comes to everyone in mid-life, has long been thought of as caused by a stiffening lens. The theory, developed by Hermann von Helmholtz, the inventor of the ophthalmoscope, used to see inside the eye, has been that aging makes the lens stiffer and less able to change its curvature. That results in blurry near vision because steeper curvature is needed for near objects to look clear.
Other than glasses or contact lenses, the standard presbyopia treatments have been:
- To replace the lens with an intraocular lens in a procedure similar to that done for treating cataracts.
- To adjust the cornea of one eye for distance vision and the other for near vision, creating what is called monovision. The brain learns to sort out this new way of receiving images.
Another Theory of Presbyopia’s Cause
Some ophthalmologists attribute presbyopia to continued growth of the lens. It is thought that the lens grows throughout life, expanding into the space needed by the ciliary muscles, which are on each side of the lens and control its curvature. With too little space, the ciliary muscles are unable to completely relax, which makes them unable to steepen the lens curvature.
Presbyopia progresses slowly after the age of 40 or 45, with a gradual loss of near vision. Distance vision remains clear and intermediate vision slowly becomes blurry, and if nothing is done and the person lives long enough, probably distance vision starts to blur also.
Based on the lens growth theory, several new treatments have been devised and are being tested worldwide. For more information on use of Scleral Expansion Bands to treat presbyopia, and on Anterior Ciliary Sclerotomy, please see our article on Presbyopia – surgical Reversal.
What is LAPR?
LAPR is a modification of Anterior Ciliary Sclerotomy and uses a laser instead of a diamond knife. It seeks to reduce the crowding of the ciliary muscles by ablating (removing) microscopic pieces of the sclera, the white part of the eye. The ciliary muscles are located beneath the sclera on each side of the cornea. By thinning out the sclera very slightly, the procedure makes more space for the muscles to stretch out and fully relax. This would restore their ability to steepen the lens curvature and provide clear near vision.
LAPR does not have FDA approval and therefore cannot be performed in the U.S. Testing is being done in many countries including the U.S. and some ophthalmologists have gone to other countries to have this done on their own eyes.
The Phase I FDA trials began in April, 2001 in Spain, after preliminary research on animals was done at the University of Utah Health and Sciences Center. Other Phase I trials have been conducted in India, the Bahamas and Venezuela.
SurgiLight, Inc. is a leading company in lasers for ophthalmic uses. In April, 2003, SurgiLight was given FDA clearance to expand and continue their presbyopia trials. Their vision correction system is called OptiVision™. The ten patients in their first study had developed no complications and all were reading without glasses three months later.
Some LAPR Progress Reports
- In 2005 SurgiLight granted a license to Biolase Technology, Inc., giving them the rights to develop an LAPR laser. Biolase is a medical technology company which develops and markets lasers and has a good reputation for its dental lasers.
Several LAPR studies are underway. One study of 55 patients showed an average improvement of 1.9 diopters. A later study demonstrated similar results with minimal regression shown at the 18-month follow-up.
- In May, 2007 at the annual meeting of the American Society of Cataract and Refractive Surgery (ASCRS) held in San Diego, a presentation was made of some FDA Phase I testing results. One Dr. Charles E. Rassier was working with several colleagues to track 30 people aged between 50 and 64 years who had been given the procedure.
An Erbium:YAG laser (an infrared pulsed laser) was used. For these 30 people, the sclera was ablated to a depth of about 80% in four pairs of ablation areas. Each was about 4.5 mm long and they were separated by spaces 2.5 mm wide.
At the time treatments were done, all participants were presbyopic but had no eye disease or systemic health problem. Now, two years later, all had only small refractive errors, meaning that their vision was close to 20/20.
Since presbyopia happens to everyone, there is a lot of interest among ophthalmologists in finding a way to cure or reverse it. Time will tell whether LAPR will receive FDA approval and become readily available throughout the U.S.
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