Information for Patients and Relatives
This guide has been designed to help you understand what Photo
Dynamic Therapy (PDT) is and how it works in treating Wet Age
Related Macula Degeneration (AMD) and other Macula diseases.
It also contains useful information on what you can expect during
treatment as well as some advice on what you should do before and
after treatment.
If, after reading this guide you have any questions about PDT or your
eye condition, be sure to discuss them with your Consultant.
What is WET age related macular degeneration
(AMD)?
The macula is at the centre of the retina at the back of the eye,
where incoming rays of light are focused. It is very important
because we use it to see straight in front of us (central vision) and
for seeing detail; for instance, when reading, writing, telling the time,
recognising faces, driving or watching television.
Sometimes the delicate light sensitive tissues of the macular can
become damaged (degenerate) and do not work as well.
There are two types of AMD, WET and DRY AMD. Dry AMD occurs
when fatty deposits build up in the tissues in the retina. Its impact on
vision is not as rapid as Wet AMD. The treatment will not help and
Dry AMD is generally managed with tools and techniques to make
the best use of your sight.
The other type, Wet AMD, is caused when faulty blood vessels grow
under the macula. These leak fluid (which is where the term ‘Wet’
comes from) and will eventually scar, leading to distortion of sight
and loss of central vision.
AMD is a very common cause of poor vision in older people but it is
not painful. It does not lead to complete loss of sight because, as it affects only the central vision, the sight in the outer edges of the eye
is retained. This is an alternative treatment to intravitreal injections
for some types of Wet AMD. Whether it is suitable for you depends
on which type of AMD and the stage it is at.
What is PDT treatment?
PDT is a treatment for the wet neovascular form of Age Related
Macular Degeneration (AMD). It uses a combination of;
1. A photosensitive (light-activated) drug called Verteporfin.
2. A red light produced by a non-thermal laser.
What does PDT treatment do?
The aim of PDT is to reduce the potential for loss of central vision
caused by Wet AMD. PDT works by destroying abnormal blood
vessels that grow behind the retina at the back of the eye. These
abnormal blood vessels leak and bleed leading to deterioration of
the macula (an area of the retina that provides your central vision).
Unlike other treatments for Wet AMD, PDT uses non thermal laser;
the light produced by this laser does not burn the retina.
In the majority of patients, PDT initially slows down the progressive
loss of sight normally experienced by patients with Wet AMD.
Thereafter, the majority of patients experience stabilisation of their
vision on PDT. In clinical trials, 6 out of 10 patients experience
stabilisation of vision over 2 years while some patients (16%) actually
experience an improvement in vision.
What are the side effects of PDT treatment?
Some patients experience adverse reactions to PDT, these include;
• Injection-site reactions such as pain, swelling, inflammation,
leakage into the area surrounding the vein, bleeding at the
injection site and hypersensitivity. • Blurred vision and other visual disturbances
• Backache during infusion (around 2.2% of patients reported
backache).
• Severe vision decrease (occurred in 1%-4% of patients).
• Photosensitivity, photo-sensitivity means sensitive to sunlight
and certain types of lights for 48 hours after laser treatment.
Please speak to your eye specialist if you experience any of these
effects after PDT.
If you have had a severe reaction to previous intravenous injections
or if you have a strong allergic history, porphyria or severe liver
disease, bring this to attention of your doctor.
If you think that you might have a sensitivity (allergy) to any
component of PDT or if you feel there is any reason why you should
not be treated with Verteporfin, do not hesitate to discuss these
matters thoroughly with your eye doctor (Consultant Opthalmologist).
What should you do to prepare for your
treatment?
PDT will cause your skin and eyes to become more sensitive to light.
Therefore, you MUST avoid direct sunlight and bright lights for 48
hours immediately after treatment.
To protect your skin and eyes please bring (or wear) the following
items with you to the Medical Retina Unit:
• Wide Brimmed Hat.
• Dark sun-glasses. A good pair of sunglasses should help to
protect the eyes from the harmful light rays that can cause
damage.
• Clothing that will fully cover your arms and legs.
• Socks and shoes.
What happens during PDT treatment?
You will be given an infusion (slow injection) of the light-activated
drug called Verteporfin into one of the veins in your arm. This lasts
for ten minutes. The nurse will then numb your eye with eyedrops.
He or she will then escort you to the laser room to complete your
treatment. Your eye specialist will place a special contact lens on
your eye. Shortly after this a red light will be directed through the
contact lens and onto the affected area of the retina. The light is
applied for exactly 83 seconds. Because the red light is produced
by a non-thermal laser there is no heating or burning. At the end of
treatment you will be given a green bracelet to wear for the first 48
hours. This is a precaution and is intended to remind you and other
health professionals that you have received PDT. Your cannula will
be removed and a dressing applied, this should remain in place for
48 hours to reduce reaction occurring.
What should you do following PDT treatment?
As mentioned before, PDT will cause your skin and eyes to become
more sensitive to light. Therefore you must avoid direct sunlight and
bright lights for 48 hours immediately after treatment. Bright lights
include but are not limited to;
• Bright sunlight
• Solariums
• Halogen lighting in homes and offices (including bright halogen
lamps and reading lamps)
• Undraped windows
Stay away from undraped windows or skylights for 48 hours and do
not rely on UV suncream to protect against photosensitivity; they will
not be effective.
After PDT you may have some vision problems. If this happens
to you, you should not drive or use machinery until your vision
improves.
Can I go outside?
If you do go out during daylight hours within the first 48 hours
following treatment, it is recommended that you wear:
• Wide brimmed hat
• Dark sunglasses
• Long sleeved shirt and trousers
• Socks and shoes
• After 48 hours, you may resume normal outdoor activities
without any special precautions.
Please note
You should not stay in the dark. In fact exposing your skin to indoor
light helps inactivate any remaining drug in the skin.
You may have some blurring of eyesight in the 48 hours following
treatment, but this is usually short lived.
If you are due to have surgery within 48 hours of the treatment
please ensure to notify your Consultant Surgeon. Avoid visiting the
dentist in the immediate 48 hours following treatment.
PDT normally involves more than one treatment to permanently
close the leaking blood vessels. Your eye doctor will normally ask
you to come back every three months to assess your eyes. He/
she will usually check your vision, take some pictures of your eye
and carry out a dye test (Fluorescein Angiography) to determine if
another treatment would be beneficial. You can expect to receive
between two and four treatments in the first year, decreasing in the
second and third year of treatment.
You will usually have had a fluorescein angiography already
before attending for your PDT appointment and been issued with
the following leaflet: “Information for patients undergoing Retinal
Fluorescein Angiography” The Angiography however will usually
be repeated at every PDT appointment as it helps the doctor to see
where the laser needs to be applied should you need treatment. You will have the fluorescein angiography in the morning and then
have a consultation with the doctor in the afternoon, he or she will
then tell you if PDT treatment would be beneficial or not based
on their examination of your eye/eyes and the findings from the
angiogram.
You will be able to leave the department to get some lunch and will
be advised on what time to return. We would strongly advise you
not to leave the hospital in between your morning and afternoon
appointments.
Useful contacts and more information
The name of your consultant ophthalmologist – Mr Khalil
The Macular Society
PO Box 1870
Andover
SP10 9AD
Helpline: 0300 3030111
General Enquiries: 01264 350551
Email: help@macularsociety.org
info@macularsociety.org
RNIB
Visit the RNIB website at www.rnib.org.uk.
Call on 0303 123 9999
NVISION
Visit NVISION website at www.nvision-nw.co.uk or email at
info@nvision-nw.co.uk or call on 01253 362692
Or write to:
NVISION Your local contacts are:
Princess Alexandria Home Linda Sethi
Bosworth Place Eye Clinic Liaison Officer
Blackpool
FY4 1SH
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Author Ophthalmology Department
Approved by Ophthalmology Governance Meeting
Date of Publication 13/11/2025
Review Date 01/11/2028
Reference No PL/1103 (v3)
