LightTouch and conventional CK uses a probe to introduce
Radio Frequency (RF) energy into the cornea. The RF energy
causes the corneal collagen to shrink. |
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One, two, or three concentric rings of treatment spots are
applied to the periphery of the cornea. |
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The shrinkage of the collagen in a circle around the periphery
of the cornea causes the edges to contract and move the
center outward, creating a myopic shift. |
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The CK probe compared to the thickness of a strand of human
hair. The LightTouch CK technique requires less pressure
as the probe enters the cornea.
Images courtesy Refractec
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LightTouch NearVision CK eye surgery is a refractive surgery procedure originally developed for hyperopia, but now used primarily as a modified form of monovision and is often an appropriate alternative to conventional
or custom wavefront Lasik, Bladeless Lasik, PRK, LASEK, or Epi-Lasik.
CK uses a probe to apply high radio frequency (RF) energy into
corneal tissue, causing shrinkage. This controlled shrinkage will
reshape the cornea to change refractive error by changing the curvature of the cornea, making
it steeper.
NearVision CK is a monovision technique that induces myopia in the patient's non-dominant eye to help people with presbyopia see items both near and distant. Presbyopia is when you need to
use reading glasses or bifocals.
There is no substantive difference between NearVision CK eye
surgery and CK, except the purpose and goal of the surgery. LightTouch
CK eye surgery is a developing CK eye surgery technique wherein
the surgeon applies very little pressure during the process. LightTouch
CK eye surgery appears to provide greater effectiveness than conventional
CK. LIghtTouch CK eye surgery can be used for NearVision CK eye
surgery monovision correction.
Monovision - But Different
Although NearVision CK eye surgery induces monovision in the
patient's non-dominant eye to provide better near vision, the effects
are not quite the same as monovision with Lasik or monovision with
a standard contact lens. Recent studies have determined that NearVision
CK eye surgery creates a multifocal cornea. This may explain why
some patients with NearVision CK eye surgery are able to see well
at near (as expected) and distance (not expected) with CK.
It is almost always a good idea to try monovision with contact
lenses before having it with surgery, however a regular single-vision
contact lens may not provide as accurate a NearVision CK experience
as using a multifocal contact lens on the non-dominant eye
and slightly over-plussing the patient. Discuss this technique with
your doctor.
Originally For Hyperopia, Now Presbyopia
CK eye surgery was first FDA approved as a treatment for hyperopia, however hyperopia
treatment with CK has been all but abandoned. Most doctors prefer
the more permanent conventional or custom wavefront Lasik, Bladeless
Lasik, PRK, LASEK, Epi-Lasik, P-IOL, or RLE to resolve hyperopia. Nearly all CK eye surgery performed
today is NearVision CK for the temporary induction of myopia of
1.00 - 2.00 diopters to improve near vision in the non-dominant
eye of presbyopic hyperopes or presbyopic emmetropes,
via spherical hyperopic treatment of 1.00 diopter to 2.25 diopters.
Most NearVision CK patients are either presbyopic or pseudophakic with single focus IOL
In The Doctor's Office
CK eye surgery is performed in a doctor's office, requiring about
three minutes of treatment per eye. Topical anesthetic drops limit
any feeling in the eye during surgery. During surgery a probe thinner
than a strand of human hair is inserted about 1/3rd of the depth
of the cornea and RF energy is applied. The energy is applied and
re-applied in a circular pattern on the outer cornea to shrink small
areas of collagen. Because this pattern is applied in the periphery
of the cornea interference with the visual axis is minimized. Shrinking the outer edge of the cornea
creates a constrictive band that will cause steepening of the curvature
of the cornea. There is no difference in the CK eye surgery process
with NearVision CK. LightTouch CK requires less pressure of the
probe into the cornea.
The release of RF energy heats the surrounding corneal tissue,
but the tip of the probe remains cool and the probe does not directly
apply heat. The heat is caused by the cornea's natural resistance
to RF energy.
Visual Recovery
The CK eye surgery patient can usually return to work or normal
activities the next day with "functional fuzzy" vision. Vision generally
begins improving in about a week's time.. The most common patient
complaints are a foreign-body sensation, excessive tearing, glare,
halos from light sources at night, general ocular discomfort, initial overcorrection, and induced astigmatism.
On the rare occasion when astigmatism problems do occur, the
quality of vision may be quite poor and even worse in low light
environments, such as driving at night. CK eye surgery seems to
have a unique healing process that often resolves part or all of
an induced astigmatism problem. The initial results settle down
in about a week, but astigmatism induced by CK may get worse for
a few weeks reaching it's worse point at about one month postop.
Vision then tends to get better with a final result 60-90 days after
surgery. For this reason, immediate enhancement surgery for induced CK astigmatism or corneal irregularities may
not be appropriate. It may be better to wait, depending upon the
exact nature of the problem.
As with any vision treatment procedure where the cornea is altered,
certain precautions should be taken. After the LightTouch NearVision
CK eye surgery procedure, patients should avoid getting contaminated
water in their eyes for at least one week. This includes water
from swimming pools, spas, lakes and the ocean. When showering or
taking baths, patients should keep their eyes closed in order to
avoid getting soap and dirty water into their eyes. When exercising,
sweat should be kept out of the eyes for at least a week after the
procedure. Also, patients should avoid rubbing their eyes vigorously
for two weeks following the procedure. Women should also avoid applying
eye makeup for one week after the procedure.
Temporary Correction
CK effects are temporary, regressing at a rate of about 1.00 diopter every 2-3 years after the initial six month healing
process. Eventually, all CK eye surgery effects will dissipate and
the cornea will return to preoperative levels. Although CK will
fully regress, it is not reversible, per se. Once the procedure
has been performed, it is not possible to "remove" its effects.
Only time will dissipate he effects of CK.
A very important caution would be to not have a permanent
surgery to correct any problem induced solely by CK. The effects
from CK are temporary. If absolutely nothing is done to the eye,
eventually all CK eye surgery effects will dissipate and the eye
will return to its condition before surgery. What is not wanted
is to use a permanent correction technique, such as Lasik, Bladeless
Lasik, PRK, LASEK, or Epi-Lasik, to correct temporary problems induced
by CK.
As an example, think of astigmatism as a bump on the cornea induced
by CK. Lasik can get rid of that bump, but eventually the CK forces
that caused the bump will dissipate. That would leave you with a
hole. You would go from one problem into another. If you need enhancement
after CK, in nearly every case the only appropriate enhancement
technique would be more CK. Enhancement with CK, often called "bonus
spots", tend to be the best response on the rare occasion when the
desired outcome is not attained with the initial surgery.
Contraindications
The LightTouch NearVision CK equipment can produce interference
that may adversely influence the operation of other electronic equipment.
Therefore, NearVision CK eye surgery is contraindicated for patients
who are wearing a pacemaker.
You should not have CK eye surgery if your cornea is unusually
thin, you have strabismus or are predisposed to strabismus, have any disease
of the eye including cataract that needs to be treated, have an irregular cornea, if you are blind
in one eye, have had previous corneal surgery including refractive
surgery, have a history of herpes
zoster or herpes simplex keratitis, respond unusually to steroids,
have glaucoma, diabetes, autoimmune disorder or immunocompromised, connective tissue
disorder, atopic syndrome, are using any ophthalmic medications other than artificial
tears, have a history of keloid formation, are pregnant, plan to become pregnant, or are lactating.
A website targeted towards the patient and sponsored by Refractec,
the manufacture of the medical device used for CK, can be found
at My Clear Vision.
Looking For Best Lasik Surgeon?
If you are ready to choose a doctor to be evaluated for conventional
or custom wavefront Lasik, Bladeless Lasik, PRK, or any refractive surgery procedure, we recommend you consider a doctor who has been evaluated and certified by the USAEyes nonprofit organization.
Locate a USAEyes Evaluated & Certified Lasik Doctor.
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