As I’ve mentioned on this blog before, near sightedness, or myopia, is a common and growing health care problem in the United States and in Asian countries. According to researchers at the National Eye Institute, part of the National Institutes of Health, rates of myopia in people ages 12 to 54 increased from 25% in 1971-72 to 41.6% in 1999-2004. In some Asian countries it has reached the rampant epidemic stage with nearly 70 percent suffering from the disorder. Studies done in China have found that those with higher education are more likely to be nearsighted and there is some evidence that suggests excessive reading and work that involves close up concentration also contributes to myopia.
Software manager Ming Chen and his family are excellent examples of how this genetic predisposition has affected a Chicago-area Chinese family. The Chens have two daughters, Courtney, age 15 and Chloe, age 17. Both Ming and his wife and both daughters are near sighted. And, like many young Chinese girls, Courtney is very studious and enjoys reading.
“Unfortunately, she often reads in poor lighting or late at night,” Ming said, confirming that his daughter’s concentration contributes to her nearsightedness.
When Ming realized his daughters had vision problems he had them examined at North Suburban Vision Consultants in Deerfield, but he admits that glasses weren’t really an option.
“My wife has always worn contact lens and the girls preferred them too,” he said. “I had heard from some friends that a new kind of contact lens was available for children who were nearsighted and decided to investigate it,” he said. His search took him to Dr. S. Barry Eiden of North Suburban Vision Consultants in Deerfield, Ill. Dr. Eiden is one of a handful of optometrists in the Chicago area offering a new type of contact lens called corneal reshaping therapy.
Overnight corneal reshaping (also termed overnight orthokeratology, corneal refractive therapy, and vision shaping treatment) is a non-surgical process that utilizes specially designed contact lenses to change the shape of the cornea. Lenses are worn overnight during sleep only. Once removed upon waking the induced flatter curvature of the cornea results in clear vision thus reducing or eliminating the dependence on contact lenses or glasses during waking hours.
“Correcting and controlling nearsightedness is very important because it potentially contributes to eye disease conditions and problems in academic and social activities,“ said Dr Eiden.
“Current thinking suggests that these CRT lenses flatten the cornea but other evidence suggests that these lenses may influence the growth in eyeball length (termed axial length). A major contributor to progressive nearsightedness is axial length elongation. Corneal reshaping may actually result in decreased axial length growth. The exact mechanism by which this happens is still being investigated,” said Dr. Eiden.
According to Dr. Eiden, Courtney began CRT in March of 2005 at the age of 10. She has done well since then and has been stable in her degree of myopia following regression and discontinuation of lens wear that took place during this time.
Courtney and Chloe are good examples of patients who are appropriate and not appropriate for CRT. Because Courtney was younger when she was examined, her prescription had not progressed past the point where CRT could be helpful. Unfortunately, Chloe’s eye sight had already deteriorated to the point where she was not a good candidate for CRT.
Two years ago, U.S. investigators started their own study of nearsighted children and teens to test whether the anecdotal information was accurate. In the “SMART” (Stabilization of Myopia by Accelerated Reshaping Technique) study, half of the subjects are fitted with Boston Equalens II gas permeable contact lens polymer in a reverse geometry/corneal reshaping lens design. The control group subjects are fitted with normal soft contact lenses worn on a daily wear basis. Dr. Eiden is one of the principle investigators of the SMART study.
The clinical study, which has 10 investigational sights located throughout the United States, has enrolled approximately 300 subjects aged 8 to 14 to determine if wearing corneal reshaping contact lenses on an overnight basis stops or slows the progression of myopia (nearsightedness) in children. Initial results of this proposed five year study have shown a significantly lower rate of myopia increase in subjects wearing the corneal reshaping lenses when compared to subjects wearing soft contact lenses.