Now you can be free of wearing contact lenses and/or glasses during the day and see clearly while performing your daily activities without undergoing surgery! Recent clinical research combined with the latest corneal surface mapping technology, computerized manufacturing and space age oxygen-breathing materials have brought new science to corneal reshaping.
Corneal Refractive Therapy or Ortho-K is a non-surgical process developed to reshape the cornea. The cornea is gently flattened, while you sleep, resulting in the temporary correction of myopia (nearsightedness) even with or moderate astigmatism (egg shaped cornea).
Similar in appearance to standard gas permable contact lenses these therapeutic lenses are designed differently to gently reshape the corneal surface while you sleep. They provide clear, natural vision when the lenses are removed upon waking.
Because ortho-k offers freedom from glasses and the hassle of wearing contact lenses during the day, this leading-edge technology can enhance the lifestyle of those requiring vision correction. Active individuals can freely participate in sports without the interference of glasses or bother of contacts. Eye irritation or dryness sometimes associated with contact lens wear due to outside dust and pollutants is eliminated.
Not everyone can wear CRT. This lens are intended for individuals with low to moderate myopia (nearsightedness up to -6 diopters) and moderate astigmatism. The larger the amount of myopia the harder it is to completely eliminate the nearsighted error. We have been very successful using corneal shaping in patients demonstrating-1.00 to -3.00 diopters of error. 90% of our patients with these myopic prescriptions acheive 20/20 with both eyes open. As your prescription increases the molding effect takes longer, but still works. We are beginning to work with hyperopia and presbyopia.
Myopia and Orthokeratology?
Two factors have changed our thinking in the last decade. Myopia has become epidemic in the United States and Asia. Researchers have reported that the prevalence of myopia has increased from 20% to 40% in the United States (Vitale et al, 2009). In Asia the number of myopic children has exceeded 80% percent in some areas of the world such as Taiwan (Lin et al, 1999). This dramatic increase provides proof of the enviormental influence on the increase in myopia.
The second major myopia development comes from corneal reshaping therapy (CRT) with contact lenses or ortho- keratology. For decades, eye doctors fitting these reshaping lenses reported that myopia appeared to develop at a much slower rate than children wearing traditonal soft lenses or glasses. For years many of us did not believe the claims of these orthokeratologists , however, numerous recent studies have demonstrated that there is significant slowing of progressive myopia or elongation of the eyes in kids wearing overnight orthokeratology versus other correction methods.
How likely is it that CRT will work for me?
In the FDA trials in 2001, of the 159 eyes targeted for 20/20 vision (who had this acuity with their best spectacles), 59% obtained 20/20 or better without other correction and 92% obtained 20/40 or better at 9 months (20/40 vision is the acuity required in most states to drive without glasses). 67% of the subjects obtained 20/20 vision in at least one eye (their better seeing eye) and 94% achieved 20/40. Our personel experience is much better due to improved fitting technology.
How long does it take to reach good vision?
Most patients have rapid improvement with accelerated CRT within the first few days of treatment they achieve 20/40 vision and achieve 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.
What are the risks of wearing CRT?
There is a small risk involved when any contact lens is worn. It is not expected that the CRT Contact Lenses for Corneal Refractive Therapy will provide a risk that is greater than other rigid gas permeable contact lenses. Because this procedure is reversible some patients may notice changes in their vision late in the day.
The two most common side effects that occur in rigid contact lens wearers are corneal edema and corneal staining. It is anticipated that the same side effects will also occur in some wearers of CRT. Other side effects that sometimes occur in all contact lens wearers are pain, redness, tearing, irritation, discharge, abrasion of the eye or distortion of vision. These are usually temporary conditions if the contact lenses are removed promptly.
In very rare instances, infections of the eye, corneal ulcer, iritis, or neovascularization, corneal scarring, permanent decreased vision may occur. The occurrence of these side effects should be minimized or completely eliminated if proper lens care is exercised.