In an eye having trouble seeing faraway, light focuses in front of the retina, making distant objects appear blurry. By using eyeglasses or daytime contacts, the light is focused on the retina so you can see clearly.
Today, CRT Contact Lenses provides a new option for patients with nearsightedness. CRT lenses correct nearsightedness or myopia, with or without low to moderate astigmatism, by gently and safely reshaping the cornea while you sleep. When the lenses are removed in the morning, the treated cornea allows light to focus on the retina. The result is clear, natural vision for your waking hours. Even if you get up during the night, the lenses will enable you to see clearly with the lenses on!
Are there any studies that show CRT being safe and effective?
CRT is FDA approved and there are several studies showing that it is safe and effective. The lenses were FDA approved in June 2002 for children and adults. CRT offers a safe, non-surgical procedure that temporarily corrects nearsightedness up to -6.00 diopters, and mild amounts of astigmatism.
Here are some of the studies from the Paragon CRT website:
SMART, a five-year study initiated in 2009, currently is evaluating the effect of corneal reshaping on myopia progression in 138 patients. At one-year follow-up, subjects wearing corneal reshaping lenses exhibited a mean progression of 0.00D, compared to an average of 0.50D in the control group. The SMART study revealed in 2011 at the Global Specialty Lens Symposium in Las Vegas, Nevada (GSLS), that both the test group and the control group of soft contact lens wearers had the same safety findings.
Source: Daniels K. Consider OrthoK for Myopia Control. Review of Optometry. 2012 July 15.
The Corneal Reshaping and Yearly Observation of Nearsightedness (CRAYON) study of two years confirmed that corneal reshaping can indeed slow eye growth in myopic children after one year of treatment. Researchers also confirmed that patients who were fitted with corneal reshaping lenses experienced significantly less annual change in axial length and vitreous chamber depth than patients fitted with soft contact lenses.
Source: Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009 Sep;93(9):1181-5.
In 2004, the results from the first report on corneal reshaping (orthokeratology) for myopia control––the Children’s Overnight Orthokeratology Investigation (COOKI) pilot study––were published. COOKI researchers evaluated refractive error, visual changes and ocular health for six months in myopic children who were fit with overnight corneal reshaping lenses. The researchers determined that overnight corneal reshaping lenses was both a safe and effective treatment for curtailing myopia progression.
Source: Walline JJ, Rah MJ, Jones LA. The Children’s Overnight Orthokeratology Investigation (COOKI) pilot study. Optom Vis Sci. 2004 Jun;81(6):407-13. Source & Content from: http://www.revoptom.com/content/c/35630/
The growing body of science supporting the role of peripheral hyperopic defocus in the growth in axial length in myopia, along with the apparent effectiveness of corneal refractive therapy in modulating the defocus, has stimulated a growing number of practitioners to recommend corneal refractive therapy (CRT) for myopia regulation.
Fortuitously, CRT for myopia results in a zone of curvature in the mid-peripheral cornea, which is shorter in radius than the post-treatment central cornea. This steeper zone causes light to be focused in front of the retina in the mid-periphery, while the central axial light is focused on the fovea.
An increasing number of practitioners worldwide are recommending CRT Brand Contact Lenses for refractive error regulation. They deem this to be in their patients’ best interest; the patients garner the benefit of vision correction without spectacle or contact lenses during their waking hours.
Source: http://www.reviewofcontactlenses.com/content/d/irregular_cornea/c/27819/
