Ortho K
Questions and Answers
What is Ortho K?
Orthokeratology, or Ortho K is a procedure where rigid gas permeable contact lenses are used to reshape the cornea, resulting in a change in refractive power.
When was the technique invented?
There seems to be some debate as to whether the Chinese Mandarins or the Aztecs of Central and Southern America first hit on the idea several hundred years ago - using sandbags placed on the closed eye during sleep to reduce levels of myopia. Not hugely practical or easy to assess, the broad principle is the same as that used today.
How long has Ortho K been available in the UK?
Pioneered in the early 1960’s using daily wear rigid lenses, Ortho K has been available in various formats in small pockets for about 40 years. Modern computerised measuring devices and high oxygen delivery lenses have, in the last few years, resulted in massive advances in success levels. Accelerated Ortho K using overnight wear lenses is now recognised as a safe and acceptable form of myopic (shortsighted) correction.
Is Ortho K expensive?
No. Considerably less expensive than laser surgery, Ortho K lenses are the same price as the most advanced one day disposable soft contact lenses.
Is Ortho K suitable for everybody?
No. Generally speaking the procedure works best with low to mid levels of myopia (short sighted). Some levels of astigmatism can also be corrected. Considerable research is being carried out on lenses used to correct higher prescriptions and will no doubt be available in the future.
Is Ortho K safe?
Yes. Although any type of contact lens wear carries a very small level of risk, Ortho K lenses are not considered to be of any greater risk than any other contact lens. In any event the lens is only to be used for around 8 hours per night, rather than the 14 to 16 hours per day commonly associated with conventional lens types.
Does age affect Ortho K?
Yes. Although there are no age barriers to Ortho K, it is widely accepted that the more mature eye takes longer to change shape and may indeed regress a little more quickly. On the positive side, some research shows that young people using Ortho K lenses are demonstrating far less myopic progression than would be the case with spectacles or other contact lens types.
Are there any disadvantages to Ortho K?
Because the cornea is elastic, some minor variations in vision during the day may be noticed. Also, some aberrations, particularly spherical aberration, may be experienced by some - often those with a large pupil or in low lighting conditions. The procedure is not permanent and if lenses are not used regularly the eye will revert back to its previous levels.
How quickly does the procedure work?
In most instances there is an improvement of around 70% after just one night wear. It may take as long as a week to achieve a satisfactory result and in some cases this may extend to a month. Because the procedure is working with an elastic and flexible structure, treatment times can vary from one patient to the next and is not always predictable.
What type of person will benefit from Ortho K?
Just about anybody who wears spectacles or conventional lenses can appreciate the huge advantages of Ortho K. Consider for a moment the keen swimmer or the Rugby player, maybe just a day in the air conditioned office or a lively day on the beach? The freedom levels of Ortho K cannot be measured.
How long do the lenses last?
Lenses will be replaced every six months.
Are the lenses just like other rigid gas permeable lenses?
No. Ortho K lenses use unique designs with reverse geometry curves - although the materials are the same as those used for conventional high oxygen delivery performance.
Are the lenses tinted?
Yes. One lens is blue and the other is lilac. This makes left and right identification easy.
Are the lenses comfortable?
The lenses are comfortable provided that the eye is either wide open or fully closed. Upon blink there is some sensation. The trick is - close your eyes and go to sleep!!
If I visit the bathroom in the night will I be able to see?
Yes. Although the lenses are made primarily for changing the curve of the eye, your prescription will be incorporated on the front surface of the contact lens - so when you wake up you will be able to see clearly - take the lenses out and you will still be able to see clearly!!!
How long does the procedure last?
It is important to wear the lenses as directed. This may be every night without fail or possibly two nights in three - there will be some variability from one individual to another. In the event that lenses are removed altogether vision returns to previous levels in around two weeks.
If it takes a few days for the procedure to be fully effective, what do I use for correcting my vision in the interim period?
Soft, daily wear lenses can be used on a very short term basis whilst the effects of the lenses are taking place.
Will I need to wear the Ortho K lenses during the day?
Possibly. In the early stages of the procedure it can be advantageous to use the lenses for short periods during waking hours.
Is the procedure invasive?
No. Unlike laser surgery, which is highly invasive and removes surface tissue, Ortho K simply changes the shape of the cornea by redistributing surface cells.
Does Ortho K reduce myopic progression?
Considerable research is underway on this subject which is difficult to assess as controlled conditions are not easy to manage. However there is more than a little evidence to suggest that myopic progression is controlled or at least slowed, particularly with young people, using Ortho K lenses.
I am over 45 years old and need reading glasses - will Ortho K correct my reading vision?
That would be nice, but no. Reading glasses will normally be needed, but many people use a technique called monovision to get round this problem - also the effects of the reverse curve in the mid peripheral area can in some instances improve reading by a notable margin, so there is more than a little hope for the mature wearer!!!
Why is Ortho K not used in all optical practices?
The procedure is relatively new, and to an extent, quite time consuming. High levels of commitment are required in time, expertise and of course financial investment in high technology equipment. It is likely that the procedure will become more widely practiced as its’ popularity grows.