What's Orthokeratology or Corneal Refractive Therapy Lenses?
If you or your relatives are nearsighted, and want to know if there is anything you can do now to slow the progressive decline in his/ her vision, you may wish to consult with your doctor about Corneal Refractive Therapy (CRT).
CRT is a process of wearing contact lenses to slow the progression of nearsightedness in children by reshaping the cornea of each eye. The patient wears the special CRT lenses to bed each night, which effectively re-shapes the cornea for up to 24 hours at a time, allowing patient to see clearly throughout the day without corrective lenses.
Using CRT lenses, if worn each night, can effectively deter any further nearsightedness and is a good choice for children who are showing signs of being just as nearsighted as their nearsighted parents.
Your doctor will gladly discuss CRT options with you and your child, to see if this therapy is a choice to address your child’s nearsightedness.
What is Paragon CRT®?
Paragon CRT is a specially designed oxygen permeable therapeutic contact lens used in Corneal Refractive Therapy.
What is Corneal Refractive Therapy?
Corneal Refractive Therapy is a sophisticated non-surgical process that temporarily reshapes the cornea while you sleep. You remove the lenses when you awake and are able to go throughout the day without any other vision correction.
How new is Paragon CRT?
The idea of contact lens corneal reshaping is not a new concept. In fact it has been around since 1960. Previous corneal reshaping designs were only as successful as technology allowed. Paragon Vision Sciences has taken the recent advancements in computerized corneal mapping, computerized manufacturing, and oxygen permeable contact lens materials to produce a therapeutic contact lens design that is like no other. This has allowed Paragon CRT to become the one corneal reshaping modality that truly stands out and the first to earn FDA approval for nighttime Corneal Refractive Therapy.
Is Corneal Refractive Therapy Permanent?
No. It’s temporary. If you stop wearing the lenses regularly while you sleep, your vision will return to its original state in as little as 72 hours.
Can everyone wear Paragon CRT?
Paragon CRT treats nearsightedness (myopia up to –6.00 diopters) with or without minor astigmatism (up to –1.75 diopters). And because there are no age restrictions on Paragon CRT, it may be the perfect option for any member of the family including active adolescents. The doctor will provide more information about Paragon CRT to see if it is right for you. Paragon CRT therapeutic contact lenses are not yet available in bifocal prescriptions for presbyopia (which requires reading glasses or bifocals). At the doctor’s discretion you may be fitted in a monovision mode (one eye corrected for near vision and one corrected for distance vision). However, since there are variations in patient physiology and visual needs, the decision for Paragon CRT, at any age, can only be made after a thorough eye exam and the recommendations of an eye care professional. At this time, hyperopia (farsightedness) is not correctable with Paragon CRT, but it is being investigated.
How long does it take to reach good vision?
Most patients have rapid improvement in the first few days of treatment and achieve nearly their optimum vision in 10 to 14 days.
What is Myopia?
Myopia, commonly known as nearsightedness, is a condition in which one sees blurry at a distance and clearer up close. This is due to an image focusing in front of the retina instead of right on the retina. Therefore, a myopic patient sees a blurred distant object.
What Causes Myopia?
The increase in myopia is partly due to the increase "near point" tasks, such as the use of computer, extensive reading, playing video games and other activities up close. Some clinical evidence indicates that the constant eye stress from near work causes the ciliary muscle of the eye to pull too strong on the retina and causes the slow elongation of the eyeball. The other factors are genetic predispositions that pass on from generation to generation.
What Age Group is Most Prone to Increase of Myopia?
The average population, globally, has a myopia count of 35-40%, whereas 60% of college graduates in the U.S. are myopic. The prevalence of myopia is even greater among Asian population. Myopia usually starts in childhood and gets progressively worse through adolescence. It normally stops increasing by late teens, but it can sometimes continue to get worse into mid-twenties.
It is important to understand that once myopia has increased to a higher degree, there is no permanent way to reverse it other than by surgical procedures. Therefore, it is important for us to consider ways to control or slow down the progression of myopia before the degree of myopia becomes very high.
Why is it important to prevent increase of Myopia?
As the degree of myopia increases, the globe of the eye also elongates and stretches the structure of the retina. Weakened retinal structure increases the risk of retinal detachment, the most prevalent blinding disease among high myopes. Other eye diseases that are common among high myopes are Retinal Degeneration and Glaucoma.
How do we control the progression of Myopia?
Generally, wearing glasses and soft contact lenses have no effect on the progression of myopia. On the other hand rigid gas permeable (RGP) contact lens (commonly called semi-soft or hard contacts) has long been known to slow down the myopia progression.
In 2005 the landmark study, Longitudinal Orthokeratology Research in Children (LORIC), conducted in Hong Kong conclusively showed nightwear Ortho-K lenses slowed down prescription increases in a large test group of children over a 2 year period.
Most recently, the Corneal Reshaping and Yearly Observation of Nearsightedness done in the Ohio State University further confirmed ortho-k's benefit of slowing down myopia. Preliminary results of this study showed an astounding 60% reduction of axial length growth among children who underwent ortho-k myopia control program.
It is generally believed that it is important to start the myopia control program with ortho-k treatment as early as possible in children to ensure the lowest prescription throughout their lives.