What is a Cataract?
A cataract
is a clouding of the natural focusing lens in your eye. It is usually
a part of the normal age related process and most people over the age of 70
have some signs of lens change. Light cannot pass through a cataract easily,
so the retina only receives blurred and distorted images. The retina is
then unable to send clear signals to the brain, and vision is gradually
impaired. Other symptoms include excessive dazzle from car headlights
or bright sunshine and the need to change glasses frequently. If cataracts
are not removed all vision may be lost, but usually only in very advanced
cases and the decision whether or not to have cataract surgery depends
on how much your daily life is affected.
Fortunately,
almost all cataracts can be successfully removed and vision restored through
modern microsurgery techniques.
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Cataract Microsurgery
Modern cataract surgery begins with a very small incision. Mr Tanner has recently introduced a new technique allowing incision size to be decreased to less than 2 mm. These small incisions seal themselves
immediately after surgery and heal over the following few weeks. No stitches
are used, and normal daily activities can be resumed soon after surgery.
Another advantage of no-stitch incisions is that they are less likely
than other incisions to cause a focusing problem known as astigmatism.
In fact, depending upon where the incision is made, no-stitch incisions
can actually reduce astigmatism which exists naturally in some patients
before surgery.
After the incision has been made, a small instrument is used to create
a round opening in the lens capsule. Another instrument, called a phacoemulsification
tip, is then inserted through this opening. Phacoemulsification uses high-speed
ultrasound waves, vibrating 40,000 times per second, to break the cataract
into tiny pieces which are then sucked out of the eye. Ultrasound is currently
the most effective method for removing cataracts.
Once the cataract has been removed, a lens implant is placed in the lens
capsule to replace the focus power of the natural lens.
Lens implants are very small ( 6-12mm) and are designed to fit permanently
within the lens capsule, where they replace the focusing function provided
by the natural lens. They are made of stable polymer plastics which will
not be rejected by the eye. Lens implants come in different powers, as
do glasses or contact lenses and are selected to improve the eye's focusing
ability. Many people discover that lens implants improve their vision
and give them greater freedom from their glasses than they enjoyed before
they developed cataracts.
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| Step 1. A clear corneal incision is made |
Step 2. The cataract is removed using ultrasound energy delivered via a
phacoemulsification machine |
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| Step 3. A replacement intraocular lens is
inserted and then unfolded in the eye |
Step 4. Following completion of surgery the new lens can
be seen sitting just behind the iris |
Painless Cataract Surgery
Thanks to recent developments in anaesthesia, cataract surgery is a painless
experience and the vast majority of operations are now done as a day case
procedure. I commonly use two kinds of anaesthesia - topical anaesthesia
and regional anaesthesia.
Topical
anaesthesia is very popular with many people because no needles
are required. Instead, topical anaesthesia simply uses drops which numb
the eye. No eye patches are needed and patients usually notice improved
vision immediately after surgery.
Regional anaesthesia involves gently injecting a local
anaesthetic into the tissues around the eye. The eye is patched for a few hours
and people begin to notice their improved vision by the next day.
Topical
anaesthesia is now my preferred technique as it offers a quicker recovery
with fewer side effects and is completely pain free. The eye is fully
anaesthetised but otherwise you are awake during the procedure, which
takes about 15 minutes. This means the operation can usually be done as
a 'day case', which has many advantages such as shortening the time in
hospital and reducing expense for the patient. Local anaesthesia also
avoids the post-operative 'hangover' from a general anaesthetic, as well
as avoiding the risks of an anaesthetic in patients with, for example,
chest problems. The majority of my patients now have their operation done
using only anaesthetic drops on the eye (topical anaesthesia), although
of course, general anaesthesia is still available for patients who prefer
to be completely asleep.
Many
patients worry that they will see what is happening during the operation.
Most patient notice a bright light and vague shapes but you cannot see
the actual instruments. Furthermore, although you have to lie fairly still, there is no need to be rigidly immobile; you can adjust your position or even cough or sneeze, provided some warning is given. These days, age or infirmity is no longer a bar to successful cataract surgery.
Risks and Benefits
In
recent years there have been enormous advances in cataract surgery that
make the operation safer and improve the visual outcome. However, you
should be aware that there is a small risk of complications, either during
or after the operation. Complications are usually treatable, possibly requiring further surgery. In a few cases serious problems such as infection or retinal detachement occur which may result in visual loss.
Mr Tanner runs a continuous audit programme and in the last 10 years has had no cases of intra-ocular infection of any kind.His results for other indicators are also significantly better than national benchmark data
Overall benefits of cataract surgery include:
Improved
Colour Vision: Colours are brighter and more vivid.
Greater
Clarity of Vision: Vision is crisper and sharper.
Improved
Quality of Life: Studies have shown that people enjoy improved
quality of life after successful cataract surgery. Many people can
resume driving and activities such as reading, sewing, golf and using
a computer are generally easier after cataract surgery.
Greater
Freedom From Corrective Lenses: Because lens implants are
selected to compensate for pre-existing focusing problems, most people
find that their vision improves considerably after surgery. Ideally,
people are able to see clearly without glasses after surgery, although
glasses may be necessary for some activities such as reading or driving.
Even people who still need to use glasses can usually use thinner
lenses than they relied upon in the past. In patients with high levels
of astigmatism I now routinely carry out additional incisions (LRI's)
to help change the shape of the eye, reducing astigmatism and decreasing
reliance on spectacles.
- Multifocal
lenses - no reading glasses: These lenses now offers the
possibility of clear focus for near and distance without the use of
glasses following cataract surgery in selected cases. Many people
are delighted with this option but it does have some drawbacks which
Mr Tanner will be happy to discuss with you in more detail.
If
you would like to make an appointment to discuss cataract surgery please
contact my personal assistant:
Telephone : 01189 553457
E-mail: secretary@tanner-eyes.co.uk
