Orthokeratology a Gentle, Safe Method of Vision Correction
Orthokeratology, also commonly known as corneal refractive therapy, vision shaping treatment, corneal molding and Ortho-K is the gentle reshaping of the cornea to correct myopia (nearsightedness). Clinical studies have shown orthokeratology slows the progression of nearsightedness in children.
History of Orthokeratology
Orthokeratology is known by numerous names and the technique has changed greatly over the years. Various forms of Ortho-k have been practiced for about 40 years. The technique first involved using progressively flatter lenses to flatten the cornea causing the patient to become less nearsighted. This early method required months to show results and the patients had to wear their lenses during part of each day or wore them on alternate days.
Corneal Molding has evolved into a method where over 80% of the patients achieve success with the first lens. Good results typically take less than a week. The process is accomplished while you sleep using a computer designed reverse geometry contact lens. The lenses are inserted at bedtime and removed in the morning. The lenses, also known as vision retainers or corneal molds, safely and gently reshape the cornea. Changing the shape of the cornea changes the eye’s focus, thus improving your vision. Most patients will have good vision throughout the day. Some patients may only need to wear their lenses on alternate nights to maintain good vision. However, for optimal myopia control, it is best to wear them every night.
Preventing the Progression of Nearsightedness in Children
Numerous recent studies have shown that orthokeratology lenses can prevent the progression of myopia (nearsightedness) in children. Why is it important to prevent the progression of nearsightedness in our children? The incidence of myopia, in the United States, increased by 66% in the last 30 years. Currently, a multi-center FDA sponsored study is in it’s fourth of five years and thus far the preliminary results are confirming that OrthoKeratology does indeed effectively prevent the progression of nearsightedness. You can find more information on how orthokeratology lenses prevent the progression of nearsightedness in children on the OrthoKDoctor.com website.
How Does it Work?
Orthokeratology is accomplished by using a specially designed contact lens called a reverse geometry lens. These computer designed lenses gently flatten the cornea by pushing the central epithelial layers that reside directly over the pupil towards the periphery. This movement of corneal cells causes the center of the cornea to be thinner thus moving the focus of light closer to the retina. Orthokeratology refocuses the light on the retina in the same way as LASIK and PRK.
The image on the left below is a normal cornea before wearing orthokeratology lenses. The middle image is the same patient after wearing an orthokeratology lens using the Gentle Vision Shaping System™ process. The image to the right shows how the corneal topography looks after LASIK (different patient).
FDA Certified Training Required of Eye Doctors to fit Overnight Orthokeratology Lenses
The methods of fitting the reverse geometry lenses used in modern Ortho-K do not follow traditional contact lens fitting methods. Because of this difference, the FDA restricts the use of these lenses to only those doctors that have been specially trained in their use. This is an additional requirement that has never been used for contact lenses; however, it is much like the requirement for the additional training required of physicians that use the excimer laser for LASIK and PRK.
This special provision for increased training and certification has never been used for contact lenses, although it has been used for other ophthalmic devices such as excimer lasers for refractive surgery procedures.
Overnight Orthokeratology is FDA Approved
Only a handful of orthokeratology lenses have been approved for overnight orthokeratology by the FDA. Contact lenses used for overnight orthokeratology were approved by the FDA in 2002.
What are My Options?
Expect your eye doctor to consult with you regarding the wide range of options that are available to you. He or she will help you focus on which vision correction option or options best fulfill your visual needs. Here are the most common vision correction options.
This is the most common, safest and simplest option. All contact lens wearers should have a pair of glasses they can fall back on when they can’t or should not be wearing their contact lenses.
A valid backup pair of glasses should meet the following requirements
- Do you mind being seen wearing them in public
- Would you be able to pass a driver’s license test with them
- Can you find them
Traditional Contact Lenses
Traditional contact lenses provide a number of options with variable replacement schedules from soft contact lenses that are discarded daily, every two weeks or monthly. There are also contact lenses that can be safely worn overnight from 6 nights to as many as 30 consecutive nights. Studies have shown that contact lens wear, even considering a lifetime of wear, is safer than refractive surgery. Both soft and gas permeable lenses can correct high amounts of nearsightedness, astigmatism, and farsightedness. Contact lenses can also correct presbyopia, allowing patients over 40 to see at both near and far without bifocal glasses or reading glasses.
Refractive surgery is a very popular option for reducing a patient’s dependency on glasses, however, not everyone is a candidate for refractive surgery. The most popular refractive procedure is LASIK or Laser ASsisted In-situ Keratomileusis, however, PRK or Photo Refractive Keratectomy is still very popular. Non-laser refractive surgeries such as a Clear or Refractive Lensectomy and Implantable Contact Lenses are also available. The non laser refractive surgeries are not nearly as popular as LASIK and PRK. There are a number of reasons why a person may not be a candidate for LASIK or PRK. We have a LASIK FAQ that answers many of the most popular questions about refractive surgery.
Why Not Have LASIK?
The most common contraindications to refractive surgery are large pupil size, thin corneas, occupation, refractive error, surgical expectations, and age. In addition, some patients simply are not comfortable with having surgery on their eyes or are hesitant to undertake something of a permanent nature such as LASIK or PRK. For more information on refractive surgery our refractive surgery FAQ.
What Should I Expect
Patients interested in Ortho-K start with either a comprehensive eye exam or a Free Ortho-K Screening. After a comprehensive eye exam, including an Ortho-K consultation, corneal topography is done. These are topographical maps of the cornea. Everyone’s topographical map is different, much like our fingerprints.
Corneal topography shows us irregularities in the cornea and is essential to designing contact lenses that will mold your cornea. Corneal topography also allows us to diagnose corneal diseases such as keratoconus. Specular microscopy may also be performed which allows us to see that the corneal cells are healthy.
The corneal topography data and the refractive data are used to design a reverse geometry gas permeable contact lens. This custom contact lens flattens the cornea, resulting in clear vision.
When we receive your new contact lenses we will call you to schedule a time to dispense your lenses, teaching you how to insert, remove, and care for them. A series of follow-up appointments will be scheduled to monitor your progress.
Most patients wear their lenses at night, while sleeping, and remove them in the morning. Some patients wear them every night and some wear them every other night.