Photodynamic Therapy (PDT)

  • Reference Number: HEY-686/2015
  • Departments: Ophthalmology Department


This leaflet has been produced to give you general information about your treatment.  Most of your questions should be answered by this leaflet.  It is not intended to replace the discussion between you and your doctor but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team caring for you.

What is Photodynamic therapy?

Since the 1960s, Photodynamic therapy (PDT) is a treatment that has been developed within various medical specialties to treat a variety of conditions.
In the eye, PDT is used in the treatment of some forms of macular degeneration and has in recent years developed a new role in the treatment of a different disease called ‘Central Serous Retinopathy’ (CSR).

During the treatment, a dye called ‘Verteporfin’ (Visudyne) is injected into a vein in the arm. The dye passes round in the circulation and then is activated by shining laser light into the eye, allowing stabilisation of abnormal leaking blood vessels at the back of the eye.

Why do I need PDT?

Two eye diseases can be treated with PDT:

  1. A small number of patients with Wet Macular Degeneration may benefit although other treatments are available.
  2. Patients with Central Serous Retinopathy (CSR) may also benefit.

Can there be any complications or risks?

Some patients experience adverse reactions to Visudyne therapy. These can include:

  • Injection site reactions such as pain swelling and inflammation.
  • You may be hypersensitive to the dye causing you to have an allergic reaction to the dye; this is very rare. You may need immediate additional treatment to deal with an allergic reaction.
  • Blurred vision following the laser treatment.
  • In clinical trials 1-4% of patients with wet Age Related Macular Degeneration (AMD) reported a severe decrease in vision following treatment. This may occur because some of the normal blood vessels inside the eye may have shut down during the treatment, or disruption of the pigment layer into the eye can cause bleeding and visual loss. This second complication is also part of the normal disease course in some patients with wet AMD.
  • As the treatment starts to have an effect, you may notice that your vision fluctuates over the next few weeks.
  • About 2% of patients experience back ache during the injection; this goes off very quickly after the injection has finished.

Patients with CSR undergoing treatment have a much better safety profile when half the dose of Visudyne is injected. This is now the standard treatment for patients with CSR. Such patients do not appear to suffer any significant reduction in vision due to the treatment.  Some patients may need more than one treatment to stabilise their disease.

How do I prepare for PDT?

Please read the information leaflet. Share the information it contains with your partner and family (if you wish), so that they can be of help and support. There may be information they need to know, especially if they are taking care of you following this treatment.

The dye makes your body very sensitive to daylight for 48 hours immediately after the treatment. Sunscreen creams do NOT offer any protection during this period. You need to wear clothes with long sleeves, trousers/leg coverings including the feet, wear a hat, gloves and dark glasses when going outside during day light hours for this period of time. On the day of treatment you need to bring with you dark glasses, gloves and a hat with a brim or coat with a hood to wear when you go home.

When you are inside, you can carry on as normal including watching television. Standard house lights pose no risk. If the sun is streaming through a particular window, we advise you to close the curtains or blinds in that particular room whilst you are in there to avoid burns to the skin. You need to be cautious when using rooms with halogen light bulbs fitted, as this type of light bulb may have a similar effect to daylight. You should also avoid attending the dentist or having surgical procedures done for 48 hours after PDT treatment, as the very bright lights used in these situations could cause burns to the skin.

What will happen?

  • You will be asked to come to the Eye Clinic for this appointment.
  • You need to allow approximately 3 hours for this visit.
  • You will have a vision check followed by the instillation of eye drops to make the pupils dilate so that we can examine the retina at the back of your eyes.
  • You may then need to have imaging of the retina performed if these have not already been undertaken at a recent clinic visit, including an OCT scan of your retina and a Fluorescein and Indocyanine Green angiogram performed to show a detailed examination of the blood circulation in the retina. Following these tests, you will see the doctor who will discuss the findings with you and decide whether PDT is needed. If we are proceeding with treatment, you will be asked to sign a consent form for the treatment, if this has not already been done.
  • A nurse will then take you to the treatment area where you will have your height and weight measured in order to calculate how much of the light sensitising dye you need.
  • You will be given a slow injection of the dye over 8-10 minutes, then there is a 2-5 minute gap to allow the dye to circulate and concentrate in the area of abnormal blood vessels in your eye (depending on the eye disease being treated).You will be positioned at a laser. Some anaesthetic eye drops are put in the eye to be treated and a contact lens placed on the eye to focus the laser in the correct position on the retina of your eye. The laser will be applied for 83 seconds. The doctor will then remove the contact lens. The treatment is then complete.

What happens afterwards?

  • We will ensure you have your protective clothing on before leaving the hospital. You will then be able to go home.
  • A follow up appointment will be arranged for 6-12 weeks later, at which time we will perform imaging tests again and repeat the treatment if necessary.
  • You need to remember to avoid daylight for 48 hours, as described above.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Ophthalmology Department on tel no: (01482) 816658, weekdays 8.30am – 5.00pm.

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.