Cataracts in Animals and their treatment

Cataracts in Animals
and their treatment
presented by the

---

Introduction
This clinic is a referral practice only - dealing with diseases of the eye in all
species of animals.
Hospitals
Our main hospitals are located in the lower North Shore and South
Strathfield in Sydney, where all our equipment is located for eye surgery.
Clinics
We also run clinics at: Baulkham Hills, Camden, the Blue Mountains, Bathurst,
Orange, Canberra and the South Coast, Newcastle and the Central Coast,
usually each month. Please ring our hospitals for information regarding these
clinics.
www.eyeclinicforanimals.com.au
64 Atchison St
Crows Nest NSW 2065
Phone: (02) 9436 4884 Fax: (02) 9906 5710
444 Liverpool Rd (Hume Highway)
South Strathfield NSW 2136
Phone: (02) 975 88 666 Fax: (02) 975 88 880
2

---

Cataracts and Cataract Surgery
What is a cataract?
Page 4
What causes cataracts?
What are the signs of cataracts?
What can we do for cataracts?
Assessment for Surgery
What happens if my animal doesn’t have cataract surgery?
What tests need to be done before cataract surgery?
Page 5
What is involved with cataract surgery in animals?
What are the success rates of cataract surgery?
What are the usual complications?
Are there risks in having a general anaesthetic?
Page 6
What happens after cataract surgery?
When will my pet see after surgery?
What is the cost of surgery?
Page 7
.. and finally
If your pet has cataract surgery
it is most important to read this booklet.
3

---

Cataracts and Cataract Surgery
What is a cataract?
What can we do for
A cataract is an opacity of the lens inside cataracts?
the eye. The lens is usually clear and In the past people have tried all sorts
transparent. The lens helps focus an of medications to clear cataracts.
image on the back part of the eye called With our current medical knowledge,
the retina. The same concept happens surgery is the only cure for cataracts.
in a camera, with the lens focussing This doesn’t mean you must have
an image on the film in the back of cataract surgery on your animal,
the camera. A camera with a foggy as some cataracts are too small to
lens is somewhat similar to having a warrant surgery. The decision as
cataract. In humans, cataracts are one of to whether your pet should have
the most common causes of blindness, surgery can be discussed with one of
especially in third world countries.
our eye specialists.
What causes cataracts?
Assessment for Surgery
Cataracts can be caused by many Early assessment of cataracts is
things. Often we can not be 100% important for two reasons:
sure of the cause. Most cataracts
seen at the Eye Clinic for Animals Firstly, to assess the retina, the light
are inherited from the parents (in sensitive membrane at the back of the
eye, to ensure it is normal. This can be
the genes), but other causes such as done most easily when the cataracts
diabetes, injuries, inflammation, are not too dense, enabling us to see
drugs and nutrition may cause the retina with the ophthalmoscope.
cataracts too.
If the cataracts are too dense we may
need to do a more specialised test
What are the
called an electroretinogram or ERG.
signs of cataracts?
Secondly, with the newer surgical
Owners usually report deteriorating equipment we use today, success of
vision. Poor vision may take the form cataract surgery is greater when the
of being more “clumsy” around the
cataracts are still in the early stages.
house, having a change in personality
(lethargy or aggression), and reluctance What happens if my animal
to go into the dark amongst other doesn’t have cataract
things. Sometimes our clients notice surgery?
a white area in the pupil (the black Cataracts can be irritating inside
circle in the middle of the eye), or their the eye if left in place. Sometimes
referring veterinarian notices the m e d i c a t i o n s c a n c o n t r o l
problem during a routine physical inflammation and help control the
examination.
associated pain. In the long term
however the inflammation may get
4

---

so bad that glaucoma (increased pressure
After being anaesthetised, your pet will
in the eye) and uncontrollable pain may
have hair clipped from around the eye
occur. In these cases the eye may need
for sterility reasons. A small area on
to be removed.
the leg will also be clipped for catheter
placement.
So even if you decide not to have
cataract surgery, please stay in touch In surgery a small incision is made
with the Eye Clinic for Animals and a fine pencil like probe is inserted
to monitor the progression of the into the eye. This probe uses the
cataract in your animal.
ultrasound energy which acts like a
jack hammer to break up the lens and
What tests need to be done remove the fragments. In some cases
before cataract surgery?
after the lens is removed, an artificial
Before considering doing cataract lens may be placed in the eye. Not all
surgery we need to make sure that dogs are candidates for an artificial lens.
the chances of success are as high The decision to place an artificial lens
as possible. We may need to test is often an intraoperative decision
the retina to see if it is in its normal made by the surgeon, depending
position by ultrasound, and to see if on various factors. The surgery itself
it is functioning normally by doing usually will take about one and a half
an electroretinogram, or ERG. (Just hours per eye.
like a camera with a foggy lens, we need
to make sure the film at the back of the What are the success rates of
camera is in its normal position, and cataract surgery?
working normally.)
Published success rates for cataract
surgery in both eyes at the same time
These tests are often done at a different
so that one eye, or both, has vision
time to the surgery itself. If your pet at 1 year after surgery is over 90%.
fails either of these tests then surgery Success rates for doing just one eye
should not be performed. If you are about 85%. This is certainly quite
are not considering doing cataract a high success rate compared to
surgery then there is also no point in almost any other surgery in the body.
doing these preliminary
However this also means that even in
tests.
uncomplicated cataract surgeries, up to
15% of cases may not work and some
What is involved
animals may even require further
with cataract surgery in
surgery.
animals?
Cataract surgery in animals is
What are the usual
almost identical to that in humans.
complications?
Some people think that cataract The most common reasons for a lack
surgery is called laser surgery. of vision after cataract surgery are
It actually involves the use of ongoing inflammation in the eye,
ultrasound energy using a process retinal detachments and glaucoma.
called phacofragementation.
T h e r e a r e o t h e r l e s s c o m m o n
5

---

complications, and these
When we do send your pet
all may contribute to the
Failure to use the
home, it is essential that
15% of cases that fail.
medications as
you use the medications we
These complications are
directed can result
prescribe at the frequency
similar to those seen in
in uncontrolled
we suggest. Failure to
human cataract surgery.
infl ammation,
use the medications
glaucoma and retinal as directed even for as
I n t h e w o r s t c a s e
detachments.
little as a day or two can
scenario, glaucoma or
result in uncontrolled
infection after surgery
inflammation, glaucoma
may not only result in lack of
and retinal detachments.
vision postoperatively, but also
uncontrollable pain with the need
For the first 1-2 weeks, it
to remove the eye.
is important to keep your
animal quiet and to limit the
exercise your pet has to strict
Are there risks in having a leash walks, preferably with a chest
general anaesthetic?
harness (not a throat collar as this can
Whether a human or an animal has a increase the pressure in the eyes).
general anaesthetic, there is always a
risk of complications and in the worst For the initial post-operative period,
case scenario this may include death.
keep your animal out of bright light
as this may cause discomfort. The eye
The published mortality incidence should be cleaned once daily using
in animals is about 0.1% (1 in 909) in a warm compress. At first we may
normal healthy dogs. To minimise the
be using medications at least 4 times
chances of an anaesthetic complication
daily. Over time this decreases.
you may like to have preoperative
blood and urine analysis performed Your first revisit after surgery
by your local veterinarian. For animals
will usually be 1 or 2 weeks after
over 10 years we advise these tests surgery. After this there will usually
should be performed. For some be another at 1 month or so after
cases we can provide a specialist surgery. Subsequent revisits will
anaesthetist at an additional cost.
depend on the progress of the case.
Once again we are trying to maximise When will my pet see after
your chances for successful surgery.
surgery?
If all goes well your pet may have
What happens after cataract vision as early as the next day after
surgery?
surgery. Some cases may however
Usually after cataract surgery your take a few weeks to fully regain vision
pet will be in hospital for up to a few due to the degree of inflammation
days.
present and also your pet “learning”
how to see again..
6

---

What is the cost of surgery? and finally ...
The cost of cataract surgery in animals
Most cataract surgery patients do well
is not the same from patient to patient after surgery. These pet owners are
as each surgery may be slightly undoubtedly some of our happiest
different.
clients. Their now visual pet is
suddenly more energetic, happy, and
The microsurgical equipment eye experiences a better quality of life.
specialists use is expensive, and many
of the materials we use in cataract Not all cataract patients have
surgery have to be imported from successful outcomes. There is always
overseas. The cost of cataract surgery a risk of complications in any surgery.
will change as a result of these and For the majority of our clients,
other factors.
the incidence of complications is
acceptable.
Please ask for an estimate at the time
of consultation. Please understand Please feel free to discuss any
that this is an estimate only, and not a further questions you may have
quote. The first recheck after cataract about cataract surgery with one of
surgery is free. After this time there the eye specialists at the Eye Clinic
will be a standard revisit fee applied.
for Animals.
After surgery you must use the medication prescribed and
keep your animal calm and out of bright light.
7

---

www.eyeclinicforanimals.com.au
64 Atchison St
Crows Nest NSW 2065
Phone: (02) 9436 4884 Fax: (02) 9906 5710
444 Liverpool Rd (Hume Highway)
South Strathfield NSW 2136
Phone: (02) 975 88 666 Fax: (02) 975 88 880
COPYRIGHT © Produced for the Eye Clinic for Animals 2001 - 2nd & 3rd printing 2002
Original illustrations and logo © Karen Curran. Produced by Unicorn Graphics Australia

---