What is Orthokeratology?
Orthokeratology, also known as Ortho-K or CRT (Corneal Reshaping Therapy) is a non-surgical procedure used to improve vision so that the need for glasses or daytime contact lenses is eliminated completely. The procedure involves the use of special therapeutic gas permeable contact lenses to reshape your cornea to reduce refractive errors while you are asleep. You only need to put the lenses on at bedtime and allow it to work overnight. By the time you wake up, your vision would have improved.
When undergoing orthokeratology treatment, the patient will observe progressive improvement in vision with clearer and sharper acuity resulting over time. Although predominantly used for myopic patients, this procedure in theory is also able to treat astigmatism and hyperopia as well. It is an effective alternative to refractive surgery, soft contact lenses, and for those who do not like to put on glasses at daytime.
How does Ortho-K work for myopia control?
This procedure is often recommended for patients diagnosed with progressive myopia because of its ability to reduce myopic progression by about 50% according to several large studies. One trial showed Ortho-K was able to slow myopic progression by upwards of 55%. The mechanism by which it provides myopic control is called peripheral myopic defocus.
Things you need to know before going for Ortho-K
Before going for the therapy, you must undergo a series of tests. Your orthokeratology optometrist will test your cornea, retina, and other parts of your eyes to determine if you are a candidate. He or she will also map your cornea with a tool known as a topographer. This is similar to a road map showing the curvature of your cornea with all the ups and downs. Apart from the information from the mapping of your cornea, your doctor also needs to know the size of your cornea, and the prescription needed for the correction of your vision. This data allows the lab to design and create the best fit ortho-k lens for your eyes.
You will be given necessary instructions on how to insert your vision retainers. You will also be given instructions on how to remove and take proper care of it. It is important that your doctor sees you after wearing your lenses for the first night. This is because your fit and corrected vision has to be re-evaluated and monitored. Your optometrist may also have to map your cornea again.
Your eye doctor has to monitor the health of your cornea, the improvement on your vision, and the effectiveness of the treatment all through the initial fitting period and on regular basis afterwards. You usually have to be seen one day, two weeks, three months and six months post wear. It is for best standard of care. You should also bear in mind that the lens fit may be modified for better and faster results. Due to its high efficacy, orthokeratology is considered to be one of the best alternative therapies to LASIK.
Although Ortho-K yields relatively fast results, the length of time it takes to get complete results differs from patient to patient because of the following factors – your presenting refractive prescription, tear quantity, tear quality, and corneal curvature and rigidity.
After initial ortho-k fit is completed
It is important that you wear your retainer lenses every night or as recommended by your eye doctor without skipping. Accuracy and precision are both important to your doctor’s evaluations. Your optometrist has to monitor the improvement of your vision closely during the first few nights of the procedure. It could slow down the treatment when recommended wear time is skipped. However, once the retaining lenses are worn again, the reshaping process resumes for clear day time vision. Many patients find this treatment option particularly liberating, specially those who lead an active lifestyle and involved in sports.