OrthoK (short for Orthokeratology) in South Africa is the great alternative to correcting one’s vision, the only non-surgical procedure that allows you to see clearly, without the use of spectacles or contact lenses during the day. This revolutionary therapy now available in South Africa and done by Mr Pieterse helps correct the corneal shape by using a contact lens for 6-8 hours per night.
The result of Orthokeratology is great vision during the day. Once the OrthoK lenses have been removed the effect last for 15 hours or more which means no spectacles or contact lenses are needed during the day.
It is clear that these lenses are changing the contact lens industry completely and over 400 000 lenses have already been fitted in the USA and other first world countries.Orthokeratology is FDA approved for nightwear and is something totally different to the general contact lens available in South Africa.
The specially designed Rigid Gas Permeable Contact lens is worn for 6-8 hours at night to gently reshape the first layer of the cornea called the epithelium. Upon awakening the cornea will have the correct shape to accurately focus light, enabling you to see clearly without the hassle of contact lenses or glasses during the day!
The retainer lenses are comfortable, easy to care for, and offer relief from the problems sometimes associated with full time contact lens wear like dryness, allergies, and foreign bodies getting on or under the lenses.
Major advantages in children include that parents do not have to be concerned about their children’s vision during the day making them spectacle free for class work and sport activities and have been shown to one of the best methods to stop the progression of myopia or nearsightedness significantly.
The result is very similar to surgical procedures such as Lasik or PRK (Laser eye surgery) with the exception that Orthokeratology is never permanent and totally reversible. It is non invasive and studies have shown that eye complications such as infections are similar to normal soft daily contact lens wear.
Kid’s vision – What is Myopia Control?
You might be wondering what can be done for Nearsigntedness (Myopia) –
Is there a cure or at least some options that should be considered to stop or halt the myopia from getting worse?
Many studies recently have proven that myopia progression can be control by slowing its progression rate during school going years. At Pieterse optometrist we do myopia control doing mainly Ortho k lenses for patients here in Johannesburg.
Watching the following vision will help you to understand Myopia control.
Why should you be interested in myopia progression or control attempts? Because reducing progression of myopia not only prevents your child from wearing thick heavy spectacle lenses but it also prevents the change from developing high risk for serious eye conditions such as retinal detachments, early cataracts, development of glaucoma and even major macular degeneration changes
Currently, the 3 top options available show promising results:
- Ortho K
- Multifocal contact lenses
- Accommodative adjusted spectacles
How does OrthoK work
OrthoK works by gently remoulding the front surface/window of the eye called the cornea. It manipulates the thickness of the epithelial cells (superficial 7 layers of corneal cells) by using the tear fluid under the lens.
The great fact of these epithelial cells is that they were designed to change their size and thickness.The cells will move around and change their shape to reach equilibrium under the lens.
The final result as shown in the video is that the corneal shape is altered by about 20 microns on removal of the lens.Recent discoveries have shown that soft contact lenses also has a slight effect on the epithelial cells, similar to OrthoK, but to a marked lesser degree. Your optometrist will therefore often request a patient to stop wearing contact lenses for a few days before an annual eye examination is done.
The cornea has an anatomical structure of 5 different layers called the Epithelium, Bowman’s membrane, Stroma, Decement’s membrane and the Endothelium. As mentioned before the orthoK lens will only change the shape of the first epithelia layer which is about 55 microns in thickness.
The tear film under the lens actually does all of the work, causing a slight microscopic fluid pressure in the centre and a slight pulling effect in the periphery of the cornea. The lens is fitted slightly closer to the central/middle cornea (5-10 micron gap) and further away with a larger gap between the retainer and the eye in the peripheral cornea. The first layer of cells is altered by approximately 20 microns causing the effect needed to see clearly. The lens itself does not physically press on the eye in any way it is the fluid under the lens that does the magic.
FREQUENTLY ASK QUESTIONS ABOUT ORTHO K
Should one rather have OrthoK than corrective laser surgery such as LASIK?
Both options have advantages and needs to be considered carefully to suit every patient’s individual needs. One advantage of OrthoK is that the retainer program will cost about 25 % of the cost of laser eye surgery. OrthoK is non-invasive and reversible, correcting the vision in a similar process to laser vision correction, and can often be claimed from your medical aid whereas with laser eye surgery most medical aids do not pay as they classify it as cosmetic surgery.
OrthoK works best for people who don’t want to wear glasses or contact lenses all day, every day — but don’t mind wearing contact lenses at night, or occasionally during the day. As mentioned before OrthoK is not a permanent result and therefore the retainer lens should be worn every night to maintain the new corneal shape.
If you use reshaping lenses for a few years and decide you still want laser eye surgery instead, Laser surgery will still be a good option. Retainer lens wear needs to be discontinued for 2-3 months before considering laser surgery.
Patients who have had laser corrective surgery correction and have regressed back to significant residual spectacle refraction are in most cases a very good candidate for Ortho K retainer lens wear as well.
What will happen when OrthoK lens wear is discontinued
One of the biggest advantages of OrthoK treatment is that once the lens wear is stopped the cornea will change back to its initial state unlike corrective laser surgery. Long term studies have shown that the orthokeratology process is completely reversible which means that once one has stopped wearing the retainer lens the refractive error will return to its pre-treatment state within 14-21 days.
If one’s primary goal is to reduce dependence on glasses or contacts during the day, then OrthoK might be a good alternative. However, if one wants to eliminate the bother of contact lenses altogether, then OrthoK is less likely to satisfy this wish.
Would one be able to wear OrthoK retainer lenses when there is a problem of dry eyes when wearing soft lenses?
OrthoK may be a good option if one suffers from dry eyes when wearing soft contact lenses. Dry eyes are less problematic with OrthoK patients, as these lenses are worn when the eye is shut and are worn for much shorter time periods compared to normal contact lens wear. When sleeping there is very little or even no tear evaporation which is normally the case during the day when one’s eyes are open. This entails no lens wear with any work that requires a high visual demand. So suddenly one will find that there is a smaller influence of environmental factors such as the air conditioning system. Dry eye patients who wear contact lenses are also more limited in terms of the type of drops used. Now drops with a lipid layer which will prevent tear layer evaporation even more, can be used.
What are the disadvantages of OrthoK treatment?
There are normally between three to five consultations during the first two months of the program. This might be a disadvantage as time in the office or at home is spent at the optometrist. Another disadvantage is that this treatment is not permanent which means that as soon as the lens wear is halted, the script will return to its original state. This therefore means that the retainer lens needs to be worn religiously; being every night or every second night depending on the script.
While the success of OrthoK is very high, it cannot be guaranteed. Although it is rare that a good candidate does not do well with OrthoK retainers, the rate and degree of change may vary from one person to the next. If one is 45 years or older, reading glasses will be needed for near work.
How safe is OrthoK treatment?
Orthokeratology is a very safe procedure when appropriately fitted and properly managed. Many patients have been able to eliminate their dependence on conventional refraction correction without any adverse effects. There is no corneal tissue that is incised or vaporised as with surgical laser procedures, which makes OrthoK a non –invasive and non-permanent procedure.
OrthoK retainer lenses are also made from state-of-the-art; high gas permeable materials so that efficient and adequate oxygen reaches the cornea in order to reduce the risk of eye infections.
To date, four University level OrthoK studies have been completed. There are currently several other studies on nightwear OrthoK being conducted. The completed studies include: The pacific 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.
An important point to understand is that nightwear should not be confused with extended wear. OrthoK retainers are only worn for an average of 6-8 hours and removed in the morning, compared to extended wear disposable soft lenses which are approved for up to 7 days of continuous wear. Also, nightwear OrthoK retainers allow up to 60% more oxygen to reach the cornea compared to extended wear disposable soft lenses. Actually these high oxygen permeable retainers are on the eye for considerably less time than even the average 12-14 hour schedule of daily wear contact lens patients.
The risks of complications for OrthoK lenses are similar to the risk of complications for soft contact lenses which can include risk for eye infections, abrasions; neovascularisation and corneal ulcers. All these complications only arise if the lenses are not worn according to the recommended guidelines.
How comfortable is OrthoK treatment?
The OrthoK lenses are made from gas permeable material and it is therefore a hard lens. Comfort can be described similar to a soft lens inverted and worn on the eye. With daytime wear of these lenses patients have complained of discomfort due to the lid interaction normally associated with these lenses. OrthoK lenses however, are slept with so these lid interactions that are normally problematic are eliminated as there is no blinking during sleeping.
Is everyone a good OrthoK candidate?
OrthoK lenses are designed to assist patients who have moderately high myopia (nearsightedness) and mild to moderate astigmatism and hyperopia (farsightedness). The procedure is generally very successful for those patients who fall within a specific script range. However the optometrist Mr Willem Pieterse will carefully examine the eye to decide if the patient will be a good candidate for this procedure.
Additional factors such as individual corneal shape and rigidity as well as the ability to wear the lenses also play a role. It is therefore important that a thorough assessment is done to really determine whether OrhtoK is for you. OrthoK has been shown to be the best method to control nearsightedness; especially in that of children. OrthK lenses also slow down the progression of nearsightedness by 40-60%. New studies indicate that there might even be a higher success rate.
Why have I not heard of OrthoK?
OrthoK lens fitting entails a great deal of technical skill, specialized equipment and more assessment time than any other conventional correction alternative. It is also more costly to the patient.
South Africa has waited for the 5 year study to test good success. Other reasons include the limited access to the technology as well as the unavailability of orthoK lenses to Optometrists in South Africa. Lenses are still ordered from international suppliers. Over 400 000 patients have been fitted worldwide in America, Australia and other first world countries.
Some optometrists and eye specialists still do not consider myopia control to be worth the time and effort or they simply believe that myopia progression is not such a big issue and/or that nothing can be done.