Non-Laser CRT

Corneal Refractive Therapy (CRT), also known as orthokeratology, is a non-surgical procedure that temporarily reduces myopia, or nearsightedness, by changing the shape of the cornea, or front surface of the eye. By changing the shape of the cornea, light is better focused on the retina, or back of the eye, to provide a clear image without refractive correction. Alternative options for refractive correction, such as glasses, contact lenses and refractive surgery, also provide clear images by focusing light on the retina. Corneal Refractive Therapy utilizes a specially designed rigid gas permeable contact lens, the Paragon CRT contact lens, to temporarily reduce myopia by flattening the cornea. A similar, permanent corneal flattening effect is produced by refractive surgery.

Contact lenses must be worn for a prescribed period each day or the cornea will return to pre-treatment levels. Although the procedure of orthokeratology has been available for nearly forty years, significant advancements in contact lens technology have recently made the procedure inviting. In June 2002, the FDA approved the Corneal Refractive Therapy contact lens, by Paragon Vision Sciences, for overnight wear for the temporary reduction of myopia (nearsightedness) and myopia with astigmatism. Paragon's lens is the first lens to receive FDA approval for overnight wear. The lens was approved for candidates over the age of 18 with myopia ranging from -0.50 to -6.00 diopters, and with astigmatism up to -1.75 diopters.