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How
does the Simple Lasik laser procedure work?
All vision
disorders for which glasses have to be used are measured in terms of sphere,
cylinder or
a combination of both. The best-corrected vision is termed 6/6 or 20/20. In simple
Lasik, the
sphere and cylinder power of a person' eye is fed into the memory of the laser machine,
and the laser then corrects the error. This means that the pattern for
correction of myopia of -2.0 will be
the same for all individuals with this error, irrespective of any person
to person eye variations. |
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How is C -
lasik better than simple lasik laser ?
It is now
known that sphere and cylinder constitute about 90-92% of the visual disorders in an
optical system of a human eye. The rest is attributed to higher order aberrations.
Correction of these aberrations along with the usual spherical and cylindrical power of the
eye result in a better sharpness and quality of vision. These higher order aberrations
along with the usual sphere and cylinder errors can now be measured and documented with
the help of a special machine called an aberrometer (OPD scan-Nidek). This machine
measures 1440 data points on the eye, records this data in the form of eye maps and the
laser beam then corrects these optical errors. Thus C-Lasik (Customized
lasik/wavefront guided lasik) is a personalized program and
would be different for every eye. |
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What is the
spectacle number that can be corrected by C-Lasik?
-1.0 to
-14.0
+1.0 to +5.0
This includes spherical and cylindrical combinations. The limits of correction will vary
in different individuals depending on the thickness of the cornea. |
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What are the
minimum requirements?
The
person should be at least 18 years of age and should not have a
significant increase in the prescribed power of spectacles in the
past one year. |
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How is
C-Lasik
laser performed?
Lasik involves
extensive computer analysis of the eye. The optical data of an eye is collected with help of an
aberrometer. This data is further
processed with a 'final fit' program in another computer and then transferred to the laser
machine. The laser machine is equipped with scanning slit and spot delivery system to
handle such treatments.
The spectacle user is then asked to come on the
scheduled day for the laser treatment. Local anesthetic eye drops are instilled in the
eye to achieve a pain free procedure. The patient is made to lie under the laser
machine and asked to fix his gaze at a red light. A special machine called the microkeratome is used to pick
up a thin corneal flap of 160 microns (equivalent to an onion skin). Laser is delivered to
the cornea under this flap to correct the spectacle number. It takes 20 to 60 seconds to
complete the laser delivery to one eye. The corneal flap is placed back in position where
it holds strongly within two minutes due to its natural bonding properties. The entire
procedure takes about 10 minutes. |
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Does the
procedure hurt?
The laser procedure
itself does not hurt. A slight pressure may be felt during the procedure. There is a
possibility of some degree of discomfort after the procedure for 3 to 4 hours which is
easily controlled by medication.
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Will I be
totally free from spectacles?
95% of the people
will be totally free from their spectacles. 5% will have mild variation from their zero
targeted correction due to varying healing patterns in different individuals, but will
have their dependency reduced on spectacles. After 3 to 6 months laser enhancement
can be attempted to correct these individuals further. People over
the age of 45 who opt for distance vision correction, may need
reading glasses. |
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Are the
results achieved from C-Lasik permanent?
The effects of
C-lasik
on the cornea are permanent. Sometimes, internal changes within an eye may come with age
and these may have some effect on the overall visual status. For example, a high myopia
may progress even after the age of 18 years, or a person may require reading glasses after
the age of forty like any normal individual. |
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When can I
return to work?
After 2 to 3 days |
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How safe is
this procedure?
C-Lasik is a very safe
procedure but like any other surgical procedure it can have some complications which are
extremely rare if a proper screening check is done prior to the procedure. This includes
measuring the corneal thickness with an ultrasound, Orbscan analysis of
the cornea and a
retina check. Nobody in our surgical experience has ever lost sight due to this procedure. |
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What is the
worst possible complication?
Infection is a
serious complication and could lead to deterioration of the cornea. Infection is usually
rare and can be well controlled with medications with little or no loss of quality of
vision. At our centre, we have had no case of infection till date. |
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How would
the eye behave after 10 to 20 years?
The medical
community can only speak of the future by accessing the data from the surgeries performed
within the last ten years. The data reveals a very positive healing response of the eye
giving doctors no reason to be concerned about effects beyond ten years. |
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Can
both eyes be done the same day?
Yes, in
most of the cases. However one eye may be done at a time by choice.
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When can I
drive?
A patient is legal
to drive when one eye is seeing 6/9 (20/30) or better. In practical terms drive when you are
comfortable with the newly set vision. |
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How long
will I be on medications?
Generally speaking a
patient is on eye drops for 8 weeks. |
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Have any
doctors had C-Lasik correction themselves?
Yes, many in India
as well in several other countries. This also includes several eye
specialists. |
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Can
I wear spectacles or contact lenses after C-Lasik surgery?
If the need arises
they can be used. |
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If I am over
50 years, will the surgery still work for me?
Each of your eyes
has two lenses - the cornea ( the general focusing lens ) and the inside lens ( the fine
focusing lens ). Laser surgery works effectively to correct the general focusing lens, no
matter what your age. However, the inside fine focusing lens of your eye hardens and no
longer provides clear reading vision after the age of 45 years. So, even after laser
surgery, you would need reading glasses after 45 years of age. However, laser surgery will
give you clear vision for all distance activities without spectacles. |
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What is the
cost of the procedure?
To
make the procedure more affordable, we have been able to bring down
the cost of C-lasik to 24000/- for both the eyes. |
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What are the
other procedures for the removal of spectacles?
The first popular procedure
was Radial Keratotomy also called the Russian technique .Here radial cuts were
given on the cornea by diamond knife. Because of the
unpredictability of the procedure, it is no longer used. E-lasik is
used when the cornea is thin. Phakic IOL and Refractive lens exchange
(RLE) is used when the number is very high. These procedures are
described below. |
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Is cataract
also treatable by Lasik laser?
No, cataract is
treatable by Phaco (Stitchless surgery)
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E-Lasik Laser (Lasek)
(Laser-insitu-Epithelial
Kerato-mileusis) |
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Indications:
Correction of spectacle
power: -1
to
-12 .
In thin cornea's where C-Lasik is not possible due to
insufficient corneal thickness.
This
procedure was specially developed for those people whose cornea is thin as seen by an
ultrasound (Pachymetry). In such individual lifting a flap with a micro-keratome as in
C-lasik may not leave sufficient corneal tissue to treat with the laser safely and hence a
complete correction of a prescription is not possible. Such cases were previously rejected
or told that a residual number will remain because the corneal thickness is insufficient
to support a full correction.
Advantage of
E-Lasik over C-Lasik
E Lasik is a tissue saving mode and is used when
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How is
E-Lasik performed
Local Anesthetic eye drop are instilled in the eye to achieve a pain
free procedure. The superficial layer of the cornea called the epithelium
is treated
with 20% alcohol for 30 seconds to loosen it up. It is then rolled up to one side. Laser
is then delivered to the cornea to correct the eye sight. The epithelium is then rolled
back to cover the lasered area. A bandage contact lens is placed over the eye where it
rests for 4 days till healing takes place. It is then removed.
Disadvantage of
E-Lasik as Compared to C-Lasik
The visual recovery in
E-lasik is not as dramatic as in C-lasik. In C-lasik the vision is almost clear the very
next day whereas in E-lasik it takes 1 week to clear up.
E-lasik is also associated
with post laser pain for which pain killers have to be used unlike C-lasik where there is
hardly any pain.
In 2% cases mild corneal
haze may develop when treating high numbers which may take some time to disappear.
Cost of
E-Lasik :-Rs. 24000/- for both eyes.
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Phakic-I.O.L
ICL
(Implantable Contact Lens )- Staar surgical, Switzerland |
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The ICL lens |
A normal looking eye with an ICL in position
which corrected a number of -18 |
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Indications:
Correction
of spectacle power: -12 or more
This
procedure is meant for those people who have very high power of
glasses, and where such numbers cannot be corrected by the usual Lasik
procedures i.e. C-lasik or E-lasik. Hence they are useful in
powers beyond – 12 or in eyes where the cornea is very thin. Here,
an Intra-ocular lens (IOL) of a special design and the required power
is positioned permanently in the eye over the natural lens of the eye.
Thus the name Implantable Contact Lens (ICL) and is not to be confused
with an ordinary contact lens which is placed over the eye and has to
be put on and removed daily.
Surgical technique:
Anesthetic drops are put in the eye to
numb the eye. No injections are used. Through a self sealing 3.0 mm
incision, the ICL is injected into the eye where it settles in
position over the natural lens. Vision is clear the very next day and
the person can resume duties after one days rest.
Advantage over C-lasik or E-Lasik
(corneal based procedures)
Lasik involves sculpting of the corneal
tissue with the laser beam. A certain mandatory thickness of the
corneal tissue has to be left behind for the normal functioning of the
eye. Correcting high powers means sculpting more corneal tissue. Since
the mandatory limits can not be crossed, there is a limit to
correction with C-Lasik or E-Lasik. In ICL, there is no sculpting of
the cornea. The lens is slid into the eye and therefore high powered
ultra-thin lenses can be cast to correct high powers.
Advantages
over RLE (Refractive lens exchange)
In 20-40 year
age group the natural lens within the eye has capacity to change focus
form distance to near vision. In RLE the natural lens is replaced by
an artificial lens which does not have the ability to change focus,
and so even though the distance vision becomes clear without glasses,
one has to still use reading glasses.
In ICL, the functioning of the natural lens is not disturbed, so this
is the procedure of choice in the age group of 20-40 year. After 40
years, the natural lens becomes hard and losses its ability to change
focus, and a reading glass in any case has to be used. So in the age
group of 40 and above, RLE becomes the procedure of choice.
Cost
Spherical
Lens Rs,11000 + US$450
(Cost of lens)
Toric Lens
Rs,11000 + US$660 (Cost of lens)
Spherical
Lens corrects only spherical power of glasses. Toric lens correct
cylinder along with spherical power of glasses. These lenses are to be
imported form Staar Surgical, Switzerland, hence cost mentioned in US dollars).
Phakic
IOL
Verisyse
(A.M.O.- USA)
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A verisyse lens from the front and side
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A verisyse lens fitted in the eye which
corrected a number of -19 |
Indications:
Correction
of spectacle power -12 or more
This
lens functions in the same way as an ICL as mentioned above except
that the design is different.
Cost: Rs
32500/- per eye including cost of lens
Vision
loss due do any other eye pathology cannot be improved by a Phakic IOL
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Indications:
Correction of
spectacle power -12 or more
This procedure is useful in
people over the age of 40 years. At this age, the natural lens of the
eye becomes hard and loses its flexibility to change focus from
distance to near vision. This natural lens is dissolved by a Phaco
needle and replaced by another lens called intraocular lens (as in a
routine cataract syrgery). The power
of this lens is such that it corrects the pre-existing high power of
the eye so that the person is now able to see comfortably without
glasses. For reading, however glasses are required.
Surgical
technique:
A
small 3 mm incision is placed in the eye and a hollow Phaco needle is
introduced through the opening. On giving energy through the tip of
the Phaco needle, the natural lens within the eye gets dissolved and
is sucked out through this needle. An artificial lens called a
foldable Intra-Ocular lens is now injected through this small opening.
Once inside the eye, it opens up and serves to replace the original
lens. Since the eye opening is very small and designed in a special
manner, it seals and no sutures are required. Hence this procedure is
also popularly known as ‘stitchless’ surgery
Cost:-Rs
13,500/-per eye
Refractive
lens exchange with multifocal lens
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Tecnis
multifocal lens (AMO-USA)
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Tecnis multifocal lens in the eye (These concentric rings on the lens
seen in the eye are visible only by special photography and are not
visible in a normal eye) |
Indication:
Correction
of spectacle power +5 or more
Correction
of spectacle power for distance and near
Here, the
natural lens is replaced by a multi-focal intraocular lens which has a dual
power. The eye sight thus improves for distance as well as for near without glasses. So one can walk around without glasses as well as
read the newspaper without glasses.
Whereas most of the spectacle number is corrected by RLE, some
pre-existing numbers like cylindrical powers cannot be corrected by
this lens exchange. Therefore, a need for using a little spectacle
power may be felt for very fine work. if such residual powers are
relatively high, they may be corrected further by lasik laser at a
later date to bring the vision closer to normal.
Cost:-
Tecnis Multifocal:
Rs 48,000/-per
eye
Restor
Multifocal: Rs 48,000/- per eye
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