What Is Orthokeratology?
In the most basic of terms Accelerated Overnight
Orthokeratology or Ortho-k is the science of changing the
curvature or shape of the cornea to change how light is focused
on the retina at the back of one's eye.
Think of the cornea as the eye's equivalent
of a watch crystal. It is a clear, dome shaped structure that
overlies the colored iris. Its tissue is most similar to clear,
wet skin; and like skin it is very pliable. Because the cornea
separates the eye from air and the rest of the outside world
and because it has a curvature that bends light towards the
back of the eye, it is responsible for most of the eye's corrective
power and contributes to various conditions such as nearsightedness
(myopia), farsightedness (hyperopia), and the blur of astigmatism.
When you choose Ortho-k a few key tests must
be performed. Chief among these tests is the determination
that your eyes are healthy. The Orthokeratologist will
examine the retina and also the health of the outside of the
eye. The other key procedure is the mapping of your cornea.
To do this an instrument called a Topographer is used. Just
like a topographical map of a camping area show hills, plains,
and valleys; the topography of the eye shows your doctor exactly
how your cornea is shaped. The information from your corneal
mapping plus the size of your cornea and the prescription
needed to correct your vision are all used to design the retainer
lenses (corneal molds) needed to create the Ortho-k effect.
On the day you pick up your Ortho-k retainer
lenses you will be instructed in how to insert, remove, and
take care your vision retainers. The fit of your retainers
will be evaluated and you will be scheduled to be seen after
your first night of wear. On day 1, your doctor will re-evaluate
your fit and newly corrected vision and another mapping of
your cornea will be performed.
Throughout your initial fitting period, your
Orthokeratologist will monitor your corneal health and the
effectiveness of treatment. At certain times your retainer
lens fit may be modified to achieve your goals.
Orthokeratology can produce results in a surprisingly
short period of time. The length of treatment to achieve your
goals can vary from patient to patient. Factors which can
affect the speed of treatment include:
- your initial prescription
- corneal rigidity
- tear quality and quantity
- your expectations.
We advise patients that they may need to use
their retainers every night to maintain their newly corrected
vision although some patients are able to vary their wearing
time to once every two to four nights. The reason for this
is due to the flexibility of your cornea. [Find
an Ortho-K Doctor]