Ortho-K and CRT
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Orthokeratology (Ortho-K) and cornea reshaping therapy (CRT)
(AKS: Refractive Therapy or cornea brace in some practice) utilizes unique designed contact lens retainers to gently mold the cornea to a new desired shape usually in a matter of hours, days, or weeks. This procedure might be compared to the way an orthodontist uses braces to align teeth. Small precise changes in corneal curvature dramatically improve vision. There is no pain and most importantly, no worry about possible complications from surgery. Results are stabilized by wearing retainer lenses at night. Many enjoy functional unaided vision all day and often longer. If retainer wear is discontinued, vision gradually returns to the original starting point. So, unlike surgery, this procedure is totally reversible. |
Orthokeratology and CRT has been successfully freeing people from their constant dependence on eyeglasses or contact lenses for over 40 years. The origin of this procedure goes back to around 1958 when a few pioneer practitioners in California found that some myopic patients prescriptions would improve after wearing hard contact lenses. Over the years, Ortho-K has evolved to a highly sophisticated science. Information derived from computerized corneal mapping can now be used with software programs to design unique reverse geometry vision retainers that can rapidly and safely correct myopia, hyperopia and astigmatism. These modern designs are often worn for only 8 hours during sleep and removed in the morning, yielding clear unaided vision during all waking hours.
Children and Orthokeratology (Ortho-K or CRT)
Recent myopia studies have revealed that gas permeable (GP) lenses offer a beneficial influence in helping retard axial elongation (growth) of the eye during the growth years. Ortho-K or CRT (made of GP lens material) is ideal for these kids because they can now function all day long with clear, natural, unaided vision. They do not have to worry about rigid lenses popping out, or debris getting trapped under their lens during athletic activities. Long term, I am literally changing a child destiny by not having him or her follow in his or her parents footsteps (or worse than their parent). Typically, we see progressive myopic children eventually reach or exceed their parent degree of prescription, but this outcome can now be changed with Ortho-K or CRT. Certainly, continuing to conform to traditional standards by allowing children to just wear eyeglasses or soft contact lenses will do absolutely nothing to retard myopic progression.
Civil Service Applicants
Individuals with poor vision desiring a career in law enforcement, fire fighting, aviation, etc., can now meet vision requirements without surgery. Ortho-K and CRT can help hundreds of candidates to secure new careers by improving their unaided vision.
Is Everyone an Ortho-K Candidate?
No! While Ortho-K can help most individuals, including those with moderately high myopia, and mild to moderate astigmatism and hyperopia, the procedure is often most effective for those prescriptions falling within a specific range. Additional factors include individual corneal shape factors and rigidity, as well as the ability to wear contact lenses. A thorough consultation and examination at Dr Zhang's office using advanced computerized diagnostic instrumentation can readily determine if Ortho-K is right for you.
No! While Ortho-K can help most individuals, including those with moderately high myopia, and mild to moderate astigmatism and hyperopia, the procedure is often most effective for those prescriptions falling within a specific range. Additional factors include individual corneal shape factors and rigidity, as well as the ability to wear contact lenses. A thorough consultation and examination at Dr Zhang's office using advanced computerized diagnostic instrumentation can readily determine if Ortho-K is right for you.
Safety
To date, four university level Orthokeratology studies have been completed. There are currently several other studies on nightwear Ortho-K being conducted. The completed studies include: The Pacific University School of Optometry (5 years), University of California at San Diego Medical School (7 years), The University of Houston College of Optometry (5 years), and the University of California at Berkeley School of Optometry (3 years). All completed studies found the procedure to be safe, without harmful side effects, and effective. These studies stressed that proper care and continued monitoring of patients under treatment is required. Only highly experienced and specialized practitioners in the field of Ortho-K therapy should utilize the procedure. An important point to understand is that nightwear should not be confused with extended wear. Nightwear vision retainers are only worn for an average of 8 hours and removed in the AM, compared to extended wear disposable soft lenses which are approved for up to 7 days of continuous wear. Also, nightwear Ortho-K vision retainers allow up to 600% more oxygen to reach the cornea as compared to extended wear disposable soft lenses. And, actually these high oxygen permeable retainers are on the eye for considerably less time than even the average 12-14 hour schedule of a daily wear contact lens patient. Recent scientific evidence seems to indicate that most of the refractive change is induced by a simple, harmless, redistribution of tissue from a 50 micron average layer of corneal epithelium. This tissue redistribution effectively flattens the central cornea, with a corresponding degree of steepening in the mid-periphery. Since the cornea represents the greatest refractive component of the eye, only a small change in curvature is normally required to create the desired visual improvement. An analogy I use to demonstrate tissue redistribution would be the lines and dimples created when removing tight shoes and patterned socks. These temporary patterns disappear over time as displaced epithelium gradually fills back in. However, since BRACE refractive therapy involves ongoing reinforcement, the results are gradually sustained for longer periods of time. After a brief period of stabilization, most individuals experience clear, functional, unaided natural vision all waking hours (or even longer).
To date, four university level Orthokeratology studies have been completed. There are currently several other studies on nightwear Ortho-K being conducted. The completed studies include: The Pacific University School of Optometry (5 years), University of California at San Diego Medical School (7 years), The University of Houston College of Optometry (5 years), and the University of California at Berkeley School of Optometry (3 years). All completed studies found the procedure to be safe, without harmful side effects, and effective. These studies stressed that proper care and continued monitoring of patients under treatment is required. Only highly experienced and specialized practitioners in the field of Ortho-K therapy should utilize the procedure. An important point to understand is that nightwear should not be confused with extended wear. Nightwear vision retainers are only worn for an average of 8 hours and removed in the AM, compared to extended wear disposable soft lenses which are approved for up to 7 days of continuous wear. Also, nightwear Ortho-K vision retainers allow up to 600% more oxygen to reach the cornea as compared to extended wear disposable soft lenses. And, actually these high oxygen permeable retainers are on the eye for considerably less time than even the average 12-14 hour schedule of a daily wear contact lens patient. Recent scientific evidence seems to indicate that most of the refractive change is induced by a simple, harmless, redistribution of tissue from a 50 micron average layer of corneal epithelium. This tissue redistribution effectively flattens the central cornea, with a corresponding degree of steepening in the mid-periphery. Since the cornea represents the greatest refractive component of the eye, only a small change in curvature is normally required to create the desired visual improvement. An analogy I use to demonstrate tissue redistribution would be the lines and dimples created when removing tight shoes and patterned socks. These temporary patterns disappear over time as displaced epithelium gradually fills back in. However, since BRACE refractive therapy involves ongoing reinforcement, the results are gradually sustained for longer periods of time. After a brief period of stabilization, most individuals experience clear, functional, unaided natural vision all waking hours (or even longer).
You Now Have A Choice
Ortho-K is a non-surgical, totally reversible procedure normally costing less than LASIK. LASIK is a non-reversible surgical procedure (good or bad). Eyes undergo normal physiological prescription changes throughout one lifetime, even after surgery So, refractive surgery is not a quick fix for the rest of your life. With Ortho-K, any normal physiological prescription changes that occur over the years can be easily compensated with new retainers. Ortho-K is totally reversible if you are not happy with the results, but there are always inherent risks with surgery. The choice is yours.
How does ortho-k work?
The GP lenses for ortho-k are applied at bedtime and worn overnight. While you sleep, the lenses gently reshape the front surface of your eye (the cornea) to correct your vision, so you can see clearly without glasses or contact lenses when you are awake. The effect is temporary generally enough to get you through a day or two so you must wear the reshaping lenses each night to maintain good vision during the day.
Who is a candidate for ortho-k?
Orthokeratology is frequently a good option for nearsighted individuals who are too young for LASIK surgery or for some other reason are not good candidates for vision correction surgery. Because it can be discontinued at any time without permanent change to the eye, people of any age can try the procedure, as long as their eyes are healthy.
Ortho-k is particularly appealing for people who participate in sports, or who work in dusty, dirty environments that can make contact lens wear difficult.
What results can you expect from ortho-k?
The goal for ortho-k is to correct your vision to 20/20 without eyeglasses or contact lenses during the day. In FDA trials of both CRT and VST lenses, more than 65% of patients were able to achieve 20/20 visual acuity after wearing the reshaping lenses overnight. More than 90% were able to see 20/40 or better (the legal vision requirement for driving without glasses in most states).
Success rates for ortho-k tend to be higher for mild prescriptions. Call our office (781) 676-2020 to find out if your prescription is within the range that can be successfully treated with ortho-k.
How long does ortho-k take?
Though you may see some improvement in your vision after a day or two of overnight ortho-k, it can take several weeks for the full effect to be apparent. During this time, your vision will not be as clear as it was with glasses or contacts, and you are likely to notice some glare and halos around lights. It is possible that you may need a temporary pair of eyeglasses for certain tasks, like driving at night, until your vision is fully corrected by the ortho-k lenses.
Is ortho-k comfortable?
Some people have comfort issues when attempting to wear gas permeable contact lenses during the day. But since ortho-k GP lenses are worn during sleep, comfort and lens awareness are generally not a problem.
Cost of orthokeratology
Ortho-k is a significantly longer process than a regular contact lens fitting. It requires a series of office visits and potentially multiple pairs of lenses. Also, GP lenses used for ortho-k are more costly than most regular contact lenses. Therefore, fees for orthokeratology are higher than fees for regular contact lens fittings.
Ortho-K prices are based on the doctor's skill, training, patient's refractive error, and complexity of individual cases. A preliminary comprehensive eye examination including corneal topography is necessary to determine if you are a suitable candidate for treatment and an experienced orthokeratologist will be able to answer specific questions pertaining to your individual case.
Can I have LASIK after ortho-k?
Yes, it is possible to have LASIK surgery after orthokeratology. But because ortho-k lenses reshape your cornea, you must stop wearing the lenses for a period of time (usually several months) so your eyes can return to their original shape and stabilize. Be sure to tell your LASIK surgeon that you worn ortho-k lenses, so they can advise you how long you should wait before having the surgery.
Why haven't I heard about Ortho-k?
The practice of Ortho-k requires a great deal of technical skill, specialized equipment and considerably more office time and is therefore more costly to the patient. Many eye doctors (including most eye surgeons) do not consider myopia control worth the time and effort. Some believe myopia progression is no big deal or nothing can be done. If a doctor is not trained in Ortho-k, or did not look into the current research on myopia treatment will not recommend it as an option during an eye exam. It is easier to offer contact lenses, glasses or refractive surgery to correct vision.
If you have any questions or concerns about the procedure, call or text us at 781-676-2020 and I will explain it to you personally.