ORTHOKERATOLOGY.
MYOPIA
REDUCTION
AND
CONTROL.
OrthoK, Wear by Night but
not by Day!
WHAT IS OrthoK?
"The reduction,
modification or elimination of refractive error by the programmed application of contact
lenses or other non-invasive procedures."
Orthokeratology uses Contact Lenses to
remould the Cornea, to reduce or correct Myopic (short-sighted) and Astigmatic (irregular
surface) errors of the eye. In some ways this is similar to the use of dental braces by an
Orthodontist to straighten crooked teeth. The main difference is that if a tooth position
is corrected for some months it will stay in the new position. However the
Cornea is highly elastic, and always returns to its original shape. For this reason the
lenses are worn nightly or on alternate nights after the ideal Corneal shape has
been achieved and removed in the morning giving perfect vision without the need for
spectacles or contact lenses.
WHY HAVE OrthoK DONE?
The main purpose of OrthoK is to be free of
both Contact Lenses and Spectacles all day.
The freedom from any artificial aid appeals
to Myopic Spectacle and Contact Lens wearers.
It is ideal for sportsmen, swimmers or
those who work in dusty or dirty environments.
Some long term contact lens wearers develop
a sensitivity to their lenses which results in reduced wearing time. OrthoK can solve
these problems.
Possibly the ideal situation for
using OrthoK is for the teenager just becoming Myopic. Not only does it have all the
advantages already given above, but the procedure appears to stabilise or retard the
progression of the Myopia.
For Myopes with higher errors, there
is sufficient reduction of the error to enable improved functional vision when the Lenses
are removed.
If you have difficulty in achieving
the required visual standard for employment then OrthoK may help.
IS EVERYONE SUITABLE FOR OrthoK?
No!
The procedure works best up to -5.00
dioptres of Myopia and -1.5 dioptres of Astigmatism.
New designs are available for prescriptions up to -10.00D and for
hyperopes upto +3.00D
The procedure also does not work as
effectively on very steep or very flat Corneas. In addition there are several unknown
factors for each individual; the complexity of the Corneal shape and the rigidity of the
Cornea itself.
Thus the speed of Corneal moulding from one
individual to the next will vary but most will achieve full correction within 3 days.
Whilst the success rate is very high, success
cannot be guaranteed due to factors outside your optometrists control.
WHAT DOES THE PROCEDURE INVOLVE?
First an initial assessment appointment to
include a full Sight Test and Computerised Corneal Topographical Scan. This gives your
optometrist a chance to both assess the general condition and health of your eyes and also
to discuss the likely effectivity of the procedure in your own case.
A pair of trial lenses are then issued for an
overnight trial and your optometrist will see you the next morning. After another
Sight test and scan, the change in your corneal shape and reduction in prescription is
assessed. If the fit is not correct then another overnight trial may be needed.
Once your optometrist has established the
correct fit and that he can reduce your myopia so that you will be able to achieve normal
vision, a pair of OrthoK lenses will be ordered. When these arrive, the fit is
assessed and you will be given them to wear every night for a week. Excellent vision and
comfort are normally maintained whilst wearing OrthoK Lenses.
You will be assessed after a week and if any
modifications are needed a new pair of lenses will be ordered.
This series of OrthoK Contact Lenses, made
from High Oxygen Permeable Rigid Material, gently reshape the Cornea towards less
curvature and a more spherical shape. This reduces Myopia and Astigmatism whilst
dramatically improving unaided eyesight.
Most of the visual changes occur rapidly in
the first few days and stabilisation procedures then follow at a slower pace over the next
few months. The program length varies between 3 and 6 months depending upon the degree of
visual error.
When the maximum results are achieved, the
final pair of lenses are worn to stabilise the new Corneal shape.
The final wearing time depends on many
variables, but the treatment aim is to have good unaided vision all or most waking
hours, with Lenses being worn overnight . Some patients will be able to wear their Lenses
every other night.
WHAT ARE THE ADVANTAGES OF ORTHOK?
Good Vision without Spectacles or Contact
Lenses for Most of the day.
It is Not a Surgical Procedure
It is Reversible.
It is Non-Invasive.
It is Modifiable.
It Does Not Hurt.
Using well established Contact Lens Fitting
Techniques mean that there are very few risks.
WHAT ARE THE DISADVANTAGES OF ORTHOK?
You must be prepared to allow for 4-10
visits over 3-6 months.
Retainer Lens Wear is essential or the
Cornea will revert to its original shape.
The degree of success is high but cannot
always be guaranteed.
The rate of improvement varies from one
person to the next.You must be prepared to follow instructions implicitly for the best
results.
DOES ORTHOK HAVE ANY ADVANTAGES OVER
EXCIMER LASER SURGERY?
Yes!
It does not involve post-operative pain.
It does not leave the hazy vision
often experienced by patients following laser surgery.
There is no loss of Bowman's membrane (the
tough protective layer just under the Corneal surface).
Both eyes are done together (rather than
several weeks or months apart).
Changes in prescription over time can be
dealt with (unlike Excimer).
OrthoK is significantly cheaper.
COST.
The procedure is time consuming and can
involve several Lens changes. However, once complete, the on-going costs are no
greater and often less than conventional Contact Lens wear.
THE FUTURE.
High Minus Prescriptions upto -10.00D
Available
NOW
Hyperopia (Long sight) upto + 3.00D
Available NOW
Presbyopia (Needing Reading Spectacles)
Coming Soon
| 
