Retinal Photodynamic Therapy (PDT)

Patient Experience

  • Reference Number: HEY-733/2023
  • Departments: Ophthalmology Department
  • Last Updated: 1 September 2023


This leaflet has been produced to give you general information.  Most of your questions should be answered by this leaflet.  It is not intended to replace the discussion between you and the healthcare team, 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.

What is Photodynamic Therapy Treatment (PDT)?

Photodynamic therapy (PDT) is a treatment that uses a combination of a “cold” laser and a special light-sensitive dye (Verteporfin).  This is injected into the blood stream to target abnormal leaking blood vessels in the retina (nerve tissue lining at the back of the eye which detects light and allows us to see) or the layer below the retina (choroid).

PDT is used in the treatment of some specific forms of wet age-related macular degeneration (AMD) and a disease called ‘Central Serous Retinopathy’ (CSR).

Why do I need retinal Photodynamic Therapy?

The combination of laser light and light-sensitive dye helps to seal off the leaking area which then reduces leakage in the retina which will either stabilise the vision (stop it getting worse) or may even improve the vision.

For patients with chronic CSR (lasting more than 6 months), there are no other proven alternative treatments apart from PDT in cases where the disease does not settle by itself within the first few months. Without this treatment there would be a risk of the leak in the retina worsening causing further damage to the eyesight.

For patients with wet age-related macular degeneration (AMD) this treatment is now reserved for patients who are unable to have the recommended first line treatment of injections of drugs into the eyeball (e.g. allergy to the drug or medical reason making it difficult for patients to attend for injection treatment) or cases where there is a specific type of wet macular degeneration where combination treatment is recommended (injections into the eyeball plus PDT treatment).

Can there be any complications or risks?

Some patients experience adverse reactions to Verteporfin/PDT treatment. These include:

  • Injection site reactions such as pain swelling and inflammation.
  • You may be allergic 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 to 4% of patients with wet 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.
  • Approximately 2% of patients experience back ache during the injection; this goes off very quickly after the injection has finished.

Patients with CSR undergoing PDT treatment have a much better safety profile as half the dose of Verteporfin dye is injected, this regimen has now emerged as 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 stabilize their disease.

How do I prepare for the Photodynamic Therapy?

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 Verteporfin dye makes your skin very sensitive to day light for 48 hours after the treatment. Sunscreen creams do NOT offer any protection during this period. You need to wear clothes with long sleeves, trousers/ leg and foot coverings, wear a hat, gloves and dark glasses when going outside during daylight hours for this period of time to prevent burns to your skin.

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.

Please do not drive to the Eye Clinic for your treatment as you will be having dilating drops which will blur your vision for up to 6 hours after the treatment and you will not be safe to drive home. 

What will happen?

The treatment is performed in the Eye Clinic at the Eye Hospital. Please report to the Reception Desk in the main entrance area at the Eye Hospital.

You will then be directed to the waiting area in the Eye Clinic.

A nurse will check your vision and put dilating drops in your eye/s. The doctor who will be doing the treatment will complete a consent form.

The nurse will weigh you and measure your height to calculate the correct dose of the Verteporfin dye.

A cannula (tube introduced into the vein in your arm with a needle) will be inserted and you will receive the Verteporfin dye through a cannula over a period of a few minutes.

You will then sit at a special machine with a chin rest attached to the laser machine.

Your eye will be numbed with some local anaesthetic drops.

The doctor will wait a specific period of 3-5 minutes depending on the treatment and then will put a special contact lens on your eye to focus the laser beam. You will be asked to keep your eye very still during the treatment to ensure the laser beam focuses on the leaking spot at the back of the eye. The treatment takes up to 83 seconds to complete (depending on the type of treatment). During the treatment the laser machine makes an intermittent long beeping noise, however please be assured that this is normal.

You may see a faint red light during the laser treatment; however the treatment is not painful.

What happens afterwards?

When the treatment is finished the nurse will remove the cannula from your arm and you will be able to go home.

You should not drive until the dilating drops have worn off (this can last up to 6 hours).

The Verteporfin dye makes your skin very sensitive to day light for 48 hours after the treatment. Sunscreen creams do NOT offer any protection during this period. You need to wear clothes with long sleeves, trousers/ leg and foot coverings, wear a hat, gloves and dark glasses when going outside during daylight hours for this period of time to prevent burns to your skin.

When inside you can carry on as normal including watching television.  Standard house lights pose no risk. Halogen type bulbs (used in some high powered reading lights, etc) can cause burns to the skin if used within 48 hours of PDT treatment, so please avoid using this type of light.

If the sun is streaming through a particular window we advise you close the curtains or blinds in that particular room whilst you are in there to avoid burns to the skin.

You should also avoid attending the dentist or having surgical procedures done for 48 hours after PDT treatment as the very bright operating lights used in these situations could cause burns to the skin.

A follow-up appointment will be arranged in a few weeks to assess response to treatment.

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) 608788.

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.

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