Re: Cataract Surgery -- Preliminary Report

On Jun 28, 2:11 am, "Churie." <Sureshvatul...@xxxxxxxxx> wrote:
On Jun 28, 5:47 am, "Mike Tyner" <mty...@xxxxxxxxxxxxxx> wrote:> "Jane" <clinton6...@xxxxxxxxxxx> wrote

Hi,
This poster will be useful I presume.

WHAT IS CATARACT?
Cataract is an opacity in the lens of the eye.In a camera, an object
is focussed onto the film by a lens. Similarly, an object seen by the
eye is focussed onto the retina by the it's lens. When the lens of our
eye gets opaque, it is called CATARACT. The normal lens allows light
to reach the retina. When it becomes opaque and does not allow light
to reach the retina, we are unable to see clearly.

To understand cataract better, imagine photographing through a camera
with grease smeared onto it's lens. In such a case, the image formed
is very hazy and blurred. Similar to grease smearing onto the lens of
a camera, if the lens of the eye gets opaque, the image formed on the
retina will be blurred and one will not see clearly.

HISTORY OF CATARACT SURGERY

The history of cataract dates back to 3000 years. The earliest
cataract operation was performed by the famous surgeon of ancient
India, SUSRUTA, a disciple of Danavantri. Even in that ancient era,
Susruta described Cataract as an opacity of the lens. He had given an
admirable account of the technique of its treatment by couching which
he successfully practiced. In this operation he displaced the opaque
cataractous lens away from the centre of the eye to another part of
the eye. Today modern medical advances have made cataract surgery one
of the most successful forms of surgery. New surgical techniques and
Intraocular lenses can restore excellent vision in 97% of all cases.
In the 1960's Dr.Charles Kelman from USA started a technique called
Phacoemulsification in which cataracts were removed through a 3 mm
incision, compared to a 12 mm incision in which the whole cataract was
removed in toto. Then in 1998, Dr.Amar Agarwal from India started a
technique called PHAKONIT in which cataracts were removed through a
1.0 mm opening. In the year 2001 a special lens was made which went
through this small opening of 1 to 1.5 mm. This was called the
Rollable Intraocular lens.
WHY DOES CATARACT FORM?

The causes of the formation of cataract are not fully known. It is
basically an aging phenomenon. Just as our hair gets grey, so also
does the lens of our eye get opaque. Next to old age come other
factors like deficiency of food like proteins and vitamins, some toxic
drugs, general diseases like diabetes, infections and injuries.
Sometimes German measles in pregnant mothers causes cataract in the
child.

TIPS BENEFICIAL TO DELAY THE ONSET OF CATARACT

1]Take good and nourishing diet rich in proteins and vitamins. Food
such as liver, eggs, milk products, carrots, cabbages and yeast are
good.

2]Protect your eyes from excessive exposure to sunrays, X-rays,
intense heat and injuries.

3]Diseases such as Diabetes and syphillis should be treated early
and effectively.

TREATMENT OF CATARACT

THERE IS NO MEDICAL TREATMENT FOR CATARACT. THE ONLY TREATMENT IS
SURGERY. The important question is when should one get operated for
cataract. This depends on the occupation of the patient. If the
patient is a pilot, he should be operated earlier for slight
deterioration of vision will affect his work, whereas if the patient
is a housewife, she can delay surgery for some time. When a person has
a cataract and the decision is made to operate, then the diseased lens
is removed and replaced by an artificial lens.

ALTERNATIVES OF THE NATURAL LENS

Once the cataract [diseased lens] is removed, there is no focussing
ability of the eye as there is no lens in the eye. So one has to use
an artificial lens to get the object focussed onto the retina. This
can be either in the form of a spectacle, contact lens or an
Intraocular lens.
1]Spectacles can be used but these are very heavy and not comfortable.
Further, if one removes these glasses the person is blind. Other
disadvantages of these glasses is that everything is magnified and the
side view is very poor.

2]The second alternative is to use a Contact lens. This is an
artificial lens placed on the eye. The disadvantage as with spectacles
is that if we remove it the person is blind as there is no focussing
ability. Another problem with contact lenses is that they have to be
put on in the morning and removed at night which is difficult for an
old person.
3]So, the best method is to give the patient an INTRAOCULAR LENS. This
is an artificial lens that is placed in the eye at the time of
surgery. It will remain in place till the end of life. By this all the
problems of spectacles or contact lenses is removed. This lens does
not irritate the eye.

MANUAL CATARACT EXTRACTION TECHNIQUE
The manual or the old technique for cataract removal use a 12 mm
incision (cut) to remove the cataract. One technique called the
INTRACAPSULAR CATARACT EXTRACTION has an incision of 12 mm. In this
the entire cataract is removed with the capsule of the lens. The
disadvantage of this technique is that the artificial lens called the
Intraocular lens (IOL) is placed in the capsular bag with the capsule
of the lens acting as a support for the lens. As the capsule is not
present the IOL cannot be placed in the capsular bag position.

Another manual technique is called the EXTRACAPSULAR CATARACT
EXTRACTION TECHNIQUE. In this the incision is about 10 mm. In this the
cataract is removed but the capsule of the lens is left behind. The
advantage of this technique is that the artificial lens called the
Intraocular lens (IOL) is placed in the capsular bag with the capsule
of the lens acting as a support for the lens.

The disadvantage of this technique is that the incision is quite large
of about 10 mm which creates scarring in the eye. This means half the
eye is cut open and then an IOL is inserted inside the eye. The IOL is
about 6 mm and so easily goes inside the eye. Sutures are then placed
and the patient admitted. The patient takes rest for 45 days and after
that suitable glasses are prescribed. The patient is given spectacles
for fine tuning after 45 days.

PHACOEMULSIFICATION

Dr.Charles Kelman from USA started a technique called
phacoemulsification in the 60's to remove cataract through a 3 mm
opening. Since then various new modalities have developed which have
made this technique more refined. The machine for removing the
cataracts is called a Phacoemulsifier machine which cuts the cataract
into small pieces and removes them by aspiration.

FOLDABLE INTRA-OCULAR LENSES
Normally, the lenses used are rigid and cannot be folded. The problem
by this is that one has to make a large cut or incision in the eye to
implant these lenses. Today, the latest development in Intraocular
lenses is the FOLDABLE intraocular lens. These are special lenses
which can be folded. Once they are folded they are placed in a special
cartridge and then the cartridge is place in a special injector. The
injector is passed into the eye and the lens also gradually passed
into the eye. The lens unfolds in the eye. These lenses can be passed
into the eye through a very small cut. Thus this foldable Intraocular
lens helps make the incision very small.

PHAKONIT (Cataract surgery through a sub 1 mm incision)

One of the biggest breakthroughs in cataract removal has come from
India by a technique called PHAKONIT. In this the incision is brought
down from a 3 mm incision to a 1 mm incision.

The first step is to make the incision. Then the instruments for
Phakonit are passed into the eye and the cataract cut into small
pieces by Phakonit and finally the whole cataract removed.
The problem with this technique was to find an IOL which would pass
through such a small incision. Then on October 2nd 2001 the first case
of a Phakonit Rollable IOL was done.

The lens used was a special lens from USA. This was the first Rollable
IOL which was implanted after a Phakonit procedure and was a rolled
IOL.

The advantage of this lens is that it is a very thin lens and when
placed in water becomes pliable and can then be rolled and inserted
into the eye. Inside the eye the lens opens gradually. The patient can
come to the hospital and go home immediately. The advantages are that
the 1 mm barrier is broken and the incision now has become so small.

MICRO-PHAKONIT
(Cataract Removed Through A 0.7 Mm Needle)
On May 21st 2005, a new technique "MICRO PHAKONIT" has been introduced
by Dr.Agarwal's Eye Hospital, Chennai whereby cataracts were removed
with a specially designed needle of 0.7 mm. The surgery was carried
out by Dr.Amar Agarwal, Director of Dr.Agarwal's eye hospital,
Chennai, India. The instruments were designed by him and manufactured
in the United States of America.

Image will come

As the incision now becomes smaller than the original phakonit
technique started in 1998, the technique has been termed Micro-
Phakonit. This technique is absolutely painless and the patient does
not require any injection at all. Since the incision is below 1 mm the
patient has no injection, no stitches and no pad. The patient walks
inside the hospital and goes back immediately.

OUT-PATIENT CATARACT SURGERY

Today, we are able to operate patients with cataract and remove their
diseased lenses and replace it with an artificial lens called an
Intraocular lens as an out-patient procedure. The patients are not at
all admitted in the hospital. The patient comes in the morning for
surgery and after the operation can go home. The patients can go back
to their work within a couple of days as the healing is very quick
because of the ultrasmall incision.
WHAT ARE THE CHANCES OF GOOD SIGHT AFTER OPERATION?

With the advancement of cataract surgery and modern skills, the
success of cataract surgery is between 97-99%. Complications like
infection and haemorrhage can occur but are very rare. One should
remember that if the retina or nerve of the eye are damaged then even
after a good cataract operation the person will not see.

Putting large lenses in large incisions is bucking the tide of
history. Small incisions offer the best chance for most-rapid, stable
visual rehabilitation of the cataract patient at the least cost,
including time of impaired vision following surgery, the need for
follow up care, the attendance of relatives to take care of them to
the doctor and the like.

SUMMARY

The advantages of performing Phakonit cataract surgery due to the very
small size of the cut made in the eye is that -

1.The patients are not admitted in the hospital

2.The patients come for the surgery and go back immediately after a
few hours in the hospital

3.There are no stitches used

4.The patient gets back to his or her normal routine the next day and
can go to office, have a head bath or do the normal housework like
cooking etc.

Take care and stay in touch.

nice summary. i don't know much about the "MICRO PHAKONIT"
procedure. sounds like i will be hearing more about it. thanks for
adding something positive to this NG.

.

Relevant Pages

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