Can Corneal Refractive Therapy (a/k/a Overnight Orthokeratology) Control of Myopia?

July 14, 2009

Researchers report positive first results from a clinical trial that tests whether specialized contact lenses slow or halt the progression of myopia in children. Data from the first-year of the study showed that the corneal reshaping lenses did control myopia progression compared with the control soft lens subjects.

Corneal refractive therapy (“CRT”) (also referred to as overnight orthokeratology or vision shaping treatment) was approved by the FDA in 2002 to treat myopia. However, as CRT was being utilized more often, anecdotal information emerged that suggested CRT might also slow the progression of the disorder compared to normal contact lenses or eyeglasses.

A new, multi-site trial (the SMART Study) began in 2007 involving hundreds of U.S. teens and pre-teens. In the SMART study, half of the participants 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.

The clinical study, which has 10 investigational sites located throughout the United States, has enrolled approximately 300 subjects aged 8 to 14. Each participant will be followed for five years and be seen at staged intervals throughout each year for evaluation. Once a year the investigators test the subject’s vision to determine how far their myopia has progressed.

This could change the way that myopic patients are managed as children and young people. The impact could be felt in many aspects of these young lives. As a myopic person myself, I am a bit envious but I will definitely follow these results closely as I have 2 myopic children of my own.

Read the release.




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2 Responses to “Can Corneal Refractive Therapy (a/k/a Overnight Orthokeratology) Control of Myopia?”

  • Dr. Ari Weitzner

    im surprised at this study- i thought it was pretty well settled that ortho-k works, but the effect wears off when the lens is discontinued. 1 year data in a study like this is not worth much- will have to wait 4 more years to get useful data, and see how much myopia retardation (0.5 diopters? 2 diopters?), and what the side effects are (corneal infiltrates/scarring? irregular astigmatism?), and whether, as i mentioned, the effect wears off after the lens is d/c’d (my understanding is that it’s the epithelium that gets effected- thinning in middle, thickening in periphery- which counteracts the myopia, which would wear off weeks after discontinuation.

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