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MACULAR DEGENERATION
Treating
Wet Macular Degeneration
Wet Macular Degeneration (MD) occurs
when new abnormal blood vessels
grow from the choroid into the retina.
This process is called choroidal neo-
vascularisation (CNV). Neo = new and
vascularisation = vessel formation.
There are a number treatments, both
proven and experimental, available for
people with Wet MD.
The treatments target these new abnormal
blood vessels that grow into the retina.
The treatments are not curative and aim to
keep the best vision for as long as possible.
In controlled
trials Lucentis has been
proven to be a safe and clinically effective
treatment for Wet MD. With monthly
injections Lucentis has shown to effectively
control Wet MD and preserve vision in
the majority of cases, and even improve it
somewhat in a minority of cases.
Patients should discuss details of the
injections with their eye specialist.
Trials are looking at varying the frequency
of injections and using it in combination
with Photodynamic Therapy with Visudyne
Lucentis
is presently not funded by the
government in New Zealand.
DIAGNOSING
WET MD
Optical Coherence Tomography
Optical Coherence Tomography (OCT) is
a non-invasive diagnostic imaging technique
that uses light to produce very high-
resolution cross-sectional images of the
tissue layers within the retina. These layers
at the macula can then be studied and
measured in microscopic detail.
By comparing the structure and thickness
of the layers measured by the OCT against
a normal healthy retina, eye specialists can
detect any Wet MD even at a very early
stage.
It is an important addition to thorough
clinical examination and is now a standard
diagnostic procedure in the diagnoses and
ongoing management of Wet MD.
Repeated tests are usually necessary to
monitor disease activity.
Treatments Proven Effective
by Controlled Trials
The abnormal growth of new blood vessels
in Wet MD causes bleeding, leakage and
scarring which results in severe loss of
central vision. This can occur very rapidly,
requiring urgency in seeking appropriate
treatments.
The new blood vessels are prompted to
grow by a protein called Vascular Endothelial
Growth Factor (VEGF).
Lucentis (ranibizumab)
Lucentis is currently the treatment of
choice for Wet MD. Lucentis is an anti-
VEGF drug which is injected into the eye
to block the protein responsible for the
growth of new blood vessels. This anti-VEGF
drug is injected into the eye cavity where
it can spread to the retina. The injections
are generally administered at four week
intervals.
OTHER
TREATMENTS
1. Avastin (bevacizumab)
Avastin is an anti-VEGF drug, like Lucentis,
which is injected into the eye. It was not
designed for use in the eye. It was primarily
tested and approved for the treatment of
cancer.
Avastin has been used worldwide in the past
2 to 3 years for treating patients with Wet
MD. Many case reports suggest that it is safe
and highly effective. In order to prove this
it is undergoing a head-to-head, controlled
clinical trial comparing it to monthly
Lucentis injections. Like Lucentis, it appears
that Avastin needs to be injected repeatedly
to maintain its effect. It is still not clear
as to how often the injection should be given.
Avastin is primarily used because it is
substantially cheaper.
2. Triamcinolone (Kenacort)
A slow release steroid designed for
injection into joints, it has been used
'off label' by some retinal specialists to
supplement CNV treatments particularly
Photodynamic Therapy.
It appears to have a beneficial effect
when used in conjunction with PDT but
has been shown in a controlled trial to be
ineffective as a sole treatment.
It is injected into the eye but promotes
cataract formation and in a third of patients
increases the intraocular pressure often
necessitating glaucoma treatment. Side
effects increase with repeated injections.