A cataract
is a clouding of the normally clear lens of the eye. When the clear
lens gradually becomes cloudy, light rays cannot be transmitted
to the retina normally, which can cause blurred vision and prevent
you from seeing near and distant objects clearly. A cataract can
occur in either or both eyes but it cannot spread from one eye to
the other.
At early stage, you may notice that your vision is blurred a little,
like looking through a cloudy piece of glass. Or you may notice
that the oncoming headlights cause more glare than before. These
symptoms may mean that your vision fails to meet legal driving standards.
What causes cataracts?
Cataracts are very common in the aging population. In Australia,
about half of those aged between 65 and 74 have some cataract. About
70 percent of those aged 75 and over have this condition.
Although aging is the most common cause, cataracts can also occur
in babies and children. They may develop as a result of injury or
eye disease and can also be associated with medical conditions such
as diabetes. Both steroids use and long term unprotected exposure
to sunlight increase the risk of cataracts too. Other risk factors
include air pollution and heavy alcohol consumption.
Cataracts are not caused by reading in a bad light or eye strain.
Symptoms of Cataracts:
A cataract is not a growth over the eye, and it won't cause pain
or discomfort.
The most common symptoms are:
Blurred vision
Glare or sensitivity to light
Poor night vision
Double vision in one eye
Needing brighter light to read
Fading or yellowing of colours
How is a Cataract diagnosed?
Your Optometrist is usually the first person to visit if your eyes
are causing you problems. A careful evaluation by your optometrist
can detect the presence of a cataract. An evaluation will also rule
out any other possible eye diseases that may be causing blurred
vision or other eye problems.
If your eyes need further treatment and care, you will be referred
to an ophthalmologist. An ophthalmologist is a medical doctor who
specialises in caring for all aspects of your eyes.
When should a cataract be removed?
It's really up to you as to when to have the surgery. Cataracts
create vision problems such as halos, blurriness, glare and dimmed
colours, and when the symptoms worsen, your quality of life and
ability to perform everyday tasks will diminish. Usually the deciding
factor is how much vision you have lost, and how much this interferes
with your enjoyment of life.
Sometimes, a change of glasses eg, stronger bifocals or the use
of magnifying lenses will be enough to temporarily improve your
vision. Many people consider poor vision an inevitable fact of aging,
but cataract surgery is a simple, relatively painless procedure
to regain vision. Cataract patients of any age group will benefit
from the surgery.
What Should You Know About
The Surgery?
Cataract surgery is performed in the operating theatre under local
anaesthesia and most people do not need to stay overnight in a hospital.
However, you will need a friend or family member to take you home,
as you may be given sedative medication during the surgery. After
the operation, your Ophthalmologist will prescribe eye drops and
arrange for you to return for post-operative care over the following
weeks. Your eye may be covered or protected for one night, until
review by your surgeon the next day. You will be able to function
normally from Day 1 but strenuous activities must be avoided for
some weeks.
What are risks of surgery?
This is one of the most common and most successful surgeries performed
in Australia today. Serious complications are very rare with modern
cataract surgery. However no surgery is entirely risk free, when
they occur they could result in loss of vision. Complications are
including endophthalmitis, posterior capsular opacification and
retinal detachment.
Ask your ophthalmologist to explain anything you do not understand.
You may wish to write down questions to ask your ophthalmologist
to help you make an informed decision.
Surgery and Intra-ocular Lens (IOL) Choice
There are many variations in technique, the most common being small
incision phacoemulsification surgery with implantation of an intra-ocular
lens chosen specifically to match your eye.
Until recently the only intraocular lens choice for most people
has been a monofocal (single focus) lens with the focus set for
distance vision. This means that reading glasses are required for
near vision. Another option is to leave the second eye with near
focus when that eye has its cataract surgery. This is called monovision,
where one eye is set for distance focus and the other for near focus.
However, this means that the distance vision in the near focus eye
without a spectacle lens is not as sharp as it could be. Many people
find this situation very useful and some find it intolerable.
In recent years newer multifocal IOLs have been produced which can
mimic natural vision and allow focusing at far and near, making
reading glasses less necessary. These multifocal IOLs can potentially
restore a full range of vision for cataract patients. They provide
the ability to simultaneously focus on faraway objects, and on near
objects. The result is increased spectacle independence across a
range of distances. Generally, Long-sighted patients have found
multifocal IOLs most easily adaptable while short-sighted patients
are not as happy with it.
Can a Cataract Return?
A cataract cannot return because the lens has been removed. However,
in about 5% of all people who have phacoemulsification, the lens
capsule later becomes cloudy, which is posterior capsular opacification.
This cloudiness of the lens capsule usually develops a year or more
after surgery. It causes the same vision problems as a cataract
does. The treatment for this condition is a procedure called YAG
capsulotomy. Your ophthalmologist uses a laser to make an opening
in the membrane behind the implant, immediately improving vision.
This is done painlessly in the office without an anaesthetic and
takes just a few minutes and does not require a hospital stay. Most
people see better after YAG capsulotomy, but, as with cataract surgery,
complications can occur. YAG capsulotomies are not performed as
a preventative measure.
What happens next?
When a cataract is removed and it is replaced by a monofocal (single
focus) lens. Normally, this will restore the distance vision. However,
Glasses will be prescribed for your new eye, particularly to help
with reading vision.
Newer generation of multifocal IOL can help you with both distance
and near vision; you may still need glasses for some activities
depending on your vision requirement.
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