Avastin (
Bevacizumab) Intravitreal Injection
Why is
Avastin Injection advised?
Macular oedema or
swelling around the macula that affects
vision but does not respond adequately
to the usual treatment methods. It can
occur with conditions such as
central retinal
vein occlusion,
diabetic retinopathy,
uveitis
(inflammation of the eyes) and others.
Without effective treatment vision loss
could progress and become permanent.
Age-related macular degeneration (ARMD)
is the leading cause of blindness in
people over 50 years of age. It is
caused by the breakdown of the central
portion of the retina called the
macula. The macula is responsible for
the fine central vision in the eye that
is needed for driving a car, reading
fine print, recognising faces, etc.
There are other similar
eye conditions that cause loss of
central vision due to abnormal growth of
blood vessels in the back of the eye.
These can occur even in young patients,
and include conditions such as high
myopia (nearsightedness) and eye
injury. Without treatment vision loss
may be quick and severe.
What does
Avastin do ?
When injected into your
eye Avastin works on inhibiting the
growth for abnormal blood vessels in the
back of the eye. This drug targets a
specific type of protein thought to
cause abnormal blood vessels growth. By
backing the stimulus it can stop the
blood vessels leaking and growing. In
some cases it actually causes the blood
vessels to regress.
What are
its limitations ?
Although some patients
have regained vision, the medication may
not restore vision that has already been
lost and may not ultimately prevent
further loss of vision caused by the
disease. Once a scar forms, it may not
be possible to restore the vision and
prevent further vision loss.
What
are the alternatives for Avastin ?
You do not have to
receive treatment for your condition,
although without treatment, these
diseases can lead to further vision loss
and blindness, sometimes very quickly.
Other forms of treatment are available.
Your ophthalmologist will
discuss with you the benefits and risks
associated with these other choices of
treatment. In addition to the approved
medications, some Ophthalmologists use
Intravitreal Triamcinolone. (Triamcinolone)
– a steroid like drug – to treat such
eye conditions.
(Another
new drug for intravitreal injection is
Lucentis
which has proven efficacy like Avastin
and has been approved by the FDA for
ophthalmic use, the only limiting factor
is cost which can be almost 10-15 times
that of Avastin.)
How is
the treatment / injection given ?
Avastin is given by an
Intravitreal injection. The drug is
injected by a retinal specialist into
the vitreous gel, which is the
jelly-like substance in the back chamber
of your eye.
This is a sterile
procedure that takes place in operation
theatre .
Local anaesthetic drops
and injection are used to numb the eye
before the procedure and antibiotic
drops have to be instilled one week
after your treatment.
This injection may have
to be repeated at regular intervals
(about every 4-6 weeks), to have a
sustained effect and whenever there is a
recurrence.
Are there
any risks or complications of systemic
Avastin?
When Avastin was given
intravenously originally to patients
with metastatic colorectal cancer, some
patients experience serious and
sometimes life-threatening complications
such as gastrointestinal perforations or
wound healing complications,
haemorrhage, arterial thromboembolic
events (such as stroke or heart attack),
hypertension, proteinuria (protein in
your urine) and congestive heart
failure.
Patients who experience
these complications not only had
metastic colon cancer but were also
given 400 times the dose you will be
given, at more frequent intervals and in
a way (through an intravenous infusion)
that spreads the drug throughout their
bodies.
Are
there any risks when it is injected in
the eye ?
None of the above serious
complications has occurred and been
reported world wide till date with the
use of intravitreal Avastin .
Ophthalmologists believe that the risk
of these complications mentioned above
is very low.
Moreover, its important
to keep in mind that the
patients receiving Avastin for eye
conditions are much healthier than the
cancer patients and receive a
significantly
smaller dose (0.05ml), delivered
only to the cavity of their eye.
Risks
of Intravitreal injections
Routine
Post Injection Advice
Your eye received
injection would have minimal or no
discomfort. It may however be slightly
red after the dressing post injection
which is temporary.
You are advised to use
the antibiotic eye drops 4 times a day
to the injected eye for a week.
You will be reviewed in 3
to 4 weeks time in the clinic.
You would be advised to
report as soon as possible if you
experience any of the adverse event
described above
Acknowledgements
Last Reviewed by Dr Mudit Bansal
18th April,2008
