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Cataract surgery is one of the
most common surgeries in the world. |
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The Cataract Surgery Process
The entire process of cataract treatment
from the decision to schedule an exam to full vision
recovery is surprisingly fast.
Cataract surgery today is significantly
advanced over surgery of just a few years ago. There are
many more options to assure the patient has the best
possible result for each set of unique circumstances.
It may be best to first learn about
cataract symptoms,
cataract causes, exactly
what is a cataract, and the potential
benefits of cataract surgery before continuing with this
article about the process of cataract surgery. You may also
want to learn about eye drops for
cataracts.
The first step to resolving cataract
problems is to know that you have a cataract. Many
cataract symptoms a patient may not immediately notice
because of the very gradual change. Many patients don't
realize they have a cataract until a routine examination by
an eye exam reveals the clouding lens or they fail the
vision test for a driver's license.
If a cataract is suspected or diagnosed,
the patient will likely be referred to an
ophthalmologist who specializes in cataract surgery. An
ophthalmologist is a medical doctor specializing in eye
medicine and surgery. A comprehensive medical eye exam will
determine if the cataract needs to be removed and evaluate
the overall health of the affected eye. A full medical
evaluation will determine if
there are any unusual medical risks that could affect the surgery
our current medications that need to be changed.
A part of the exam will be a manifest
refraction (which is better, one or two?) to determine the
patient's
best corrected vision.
Ultrasound size measurements of the
eye will be taken to determine the most appropriate power for the
replacement lens.
Cataracts need to be removed when they
begin to interfere with the patient's normal activities.
This threshold will be different for every patient because
each patient has a unique set of activities that may be more
or less demanding on vision requirements. If a cataract is
not interfering with a person's quality of life, then
removal is not required, but may be optional.
The vast majority of cataract patients
choose to have an artificial lens implanted to replace the
removed defective lens, rather than wear thick glasses or
contact lenses. This intraocular lens (IOL) will
reduce the need for glasses and if glasses are required, they
will be much thinner and lighter than if an IOL was not
implanted.
The primary choices of IOLs are
monofocal,
multifocal, and
accommodating. Each has its own set of advantages and
disadvantages. Multifocal and accommodating IOLs are
designed to reduce the need for reading glasses, but are not
for everyone. Only after careful discussion with the doctor
can the patient match required benefits to required needs.
Another choice to reduce the need for
reading glasses is
monovision correction. Monovision is when one eye is
focused on near objects and one eye is focused on distant
objects. The brain blends the two images for both distance
and near vision. Many seniors use monovision with contact
lenses prior to cataract surgery and may have IOL lenses
that replicate that effect.
After examination, diagnosis, decision
to proceed, and choice of IOL have been completed, the
doctor will provide instructions with general preparation
for surgery and for medications that need to be discontinued
or changed. An informed consent will be provided. The
informed consent is not just a formality. It is a key
document to educate the patient about the potential risks of
cataract surgery. It should be read completely and any
questions about its contents should be asked and answered
before it is signed.
The surgery will be scheduled on an
outpatient basis, usually at a hospital or ambulatory
surgery center. The patient will go home the same day as the
surgery. Transportation home from the surgery center needs
to be arranged. The patient will not be allowed to drive
immediately after surgery. Depending upon the time of
surgery the patient will be instructed to not eat breakfast
and/or lunch on the day of surgery.
If there has been any part of the
preoperative instructions that have not been followed,
notify the doctor or staff immediately upon arrival to
the surgery center. Notify the doctor or staff of any
additional information, such as a drug that had previously
not been disclosed or new medication prescribed since the
last doctor's appointment or an over-the-counter drug that
has been used recently. What may seem inconsequential may
actually be very important in the success of cataract
surgery.
Shortly after arrival the patient will
be provided eyedrops and perhaps a mild sedative.
The patient may be dressed in a surgery
gown or otherwise covered in sterile material. After being
positioned on a specially adjustable operating table, the
skin around the eye will be thoroughly cleansed, and sterile
coverings will be placed around the head. A local anesthetic
will numb the eye. Light and movement may be seen, but the
patient will not be able to see the surgery as it happens.
When brought into the operating room the
patient will be positioned under a large surgical microscope
at the head of the table. The surgeon will sit above the
patient, as if upside down to the patient.
The most common method used for cataract
removal and IOL implantation is called phacoemulsification extracapsular cataract
extraction. A very small incision
is made at the outer edge of the cornea (clear front of the
eye), just above the white part of the eye. Some doctors use
two small incisions apart from each other, but the surgery
will be performed through a small incision.
The natural crystalline lens of the eye
is similar to a grape. It has a tough outer shell, called
the capsule, a hard center, called the nucleus, and pulpy
soft cortex between the capsule and the nucleus.
The surgeon will create a small hole in
the front of the capsule. Using special tools that apply
ultrasonic energy, the nucleus and the cortex are broken
into small fragments and removed with gentle suction. The
lens capsule remains largely intact to create a "bag" still
secure in the eye into which the IOL will be positioned.
All this will be performed through the
tiny incision at the edge of the cornea.
A synthetic artificial lens will be
implanted into the capsular bag after the defective portion
of the natural lens has been removed. Some lenses are able
to be folded so small that they can be inserted through the
tiny incision and then gently unfold within the eye. Other
lenses may require the incision to be enlarged.
Often sutures are not required to seal
the incision, it is so small and tight.
The protective sheeting at the eye will
be removed, the area will be washed, and a protective patch
will be positioned over the patient's eye and held in place
with surgical tape.
The surgery process will require 15-25
minutes.
The patient will be taken into a waiting
area. The surgeon may want to check the eye again before the
patient goes home.
The patient will be required to use
various eye drops as prescribed. Care not to rub or apply
pressure to the eye must be taken. The patient should avoid
driving, bright light, strenuous activities, bending, and changes in
medications until approved by the doctor. The eye shield or
dark eyeglasses will be required until the doctor determines
the eye is ready for the environment, normally one to two
weeks.
Recovery is generally short, with stable
healing occurring within 2 to 6 weeks and complete healing
at three months. Some
people have noticeable improvement in their vision from the
day after surgery onward, while others need more time for
their vision to clear.
Recovery may be delayed because of
pre-existing conditions such as glaucoma, diabetes, etc. or
delayed due to
cataract surgery complications, however the vast
majority of side effects are fully resolved.
Cataract Surgery Results
About 46% of cataract patients are 20/20
after cataract surgery and without the need for glasses or
contact lenses. About 90% are 20/40 or better without
glasses, which is the
minimum requirement to maintain a driver's license. If the
patient has other ocular health issues such as diabetes,
glaucoma, high myopia, etc., then about 30% are 20/20
without glasses and 80% are 20/40 or better. See
Cataract Surgery Results for more details.
In about 50% of all cataract patients
the capsule of the lens will become clouded, often known as
secondary cataracts. Recent studies indicate that the
shape and type of material used in the intraocular lens may
be associated with more or less development of capsule
clouding. If the secondary cataract limits vision, a laser
will be used to open the capsule so light may pass through
unobstructed.
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