Paragon CRT Contacts
Wouldn't it be great if your vision could be corrected while you were sleeping? If you answered yes, then please read on. Nearsighted patients can now greatly reduce their dependence on glasses, or eliminate the need to wear them altogether... without surgery! This new development in vision care, approved by the FDA in June 2002, is called Corneal Refractive Therapy, or CRT.
Myopia and its correction
Nearsightedness (myopia) is caused by a mismatch between the optical elements of the eye and the length of the eye. When the eye's optical elements (cornea and lens) are of the ideal strength, they focus light from distant objects precisely on the inside back of the eye (called the retina.) This results in the clearest vision. In myopia, the optical elements of the eye are too strong and focus light from distant objects in front of the retina, resulting in blurry vision.
Normally, correction of myopia involves reducing the overall focusing power of the eye's optical elements by introducing a "minus" lens in front of the eye. If you are nearsighted, your prescription contains negative numbers (-2.50 D.S., -2.00-1.00x180, etc.) These negative numbers indicate the minus lenses needed to cause light to focus precisely on your retina and give you the clearest vision.
While both the internal lens of the eye and the external cornea determine the eye's overall light focusing strength, the cornea is by far the more powerful of the two. The curvature of the cornea is largely what determines how strongly it focuses light. The more curved the cornea is, the more focusing power it has. Through corneal reshaping, the curvature of the cornea can be reduced. Reducing the corneal curvature has the same effect as introducing a minus lens in front of the eye.
The CRT procedureThe cornea is very elastic and can be molded easily. Patients insert the specially designed CRT lenses when they go to bed. During the night, the lenses gently reduce the curvature of their corneas. In the morning, the CRT lenses are removed. Since the corneal curvature has been temporarily reduced, the amount of nearsightedness present has been reduced as well. For many people, vision is improved enough that glasses will not be needed during the day.
Frequently asked questions
Is CRT safe? CRT has been approved by the FDA. Over ten years of testing and clinical trials went into the development and manufacture of Paragon Corneal Refractive Therapy lenses. The development of CRT rose from sophisticated new technologies in computerized corneal mapping and oxygen permeable contact lens materials, making the process both safe and highly effective.
How long does CRT take? Most patients have rapid improvement in the first few days of treatment and have achieved nearly their optimum vision in 10 to 14 days. A small percentage of patients will not improve enough to function under all conditions without additional correction.
Will I be able to see while wearing the CRT lenses? One of the nice advantages of CRT is that if you have to get up in the middle of the night, you will be able to see clearly.
Is CRT reversible? Yes; if you quit wearing the lenses completely, your eyes will return to their original shape. The fact that CRT is reversible is one of the factors that many people find comforting.
Who is a candidate? CRT is for people of any age who are nearsighted - even children and teenagers. The FDA has approved CRT for people with up to six diopters of myopia (-6.00 as the first number in your prescription); CRT is also approved for use with up to -1.75 diopters of astigmatism.
What vision problems are not suited to CRT correction? CRT is not for correction of farsighted vision problems. Also, people with severe nearsightedness or severe astigmatism are usually not good candidates. Except in selected cases, CRT is not used to correct focusing problems that develop in middle-age. Your eye doctor will discuss your options with you and make recommendations based on your prescription and lifestyle needs.
What medical conditions exclude someone as a candidate for CRT?
In conclusionCorneal refractive therapy offers convenience and puts an end to the need to wear glasses during the day for many patients. Whether you are playing sports, working in a dusty or windy environment, or simply applying makeup, with Corneal Refractive Therapy nothing needs to stand between you and excellent vision. Just wear the CRT lenses while you are sleeping and take them out in the morning.
To determine if you are a good candidate, schedule an examination appointment with your eye doctor. Be sure to mention that you have an interest in CRT when you call.
VISION & HEALTH NEWSLETTER COURTESY OF:
James Mayer, O.D., F.C.O.V.D.
501 Marin St