• about PDT laser
  
• different types of CNV (wet macular degeneration) with different responses to laser
  
• Who is eligible for NHS Verteporfin PDT Cohort Study?
  
• some notes
  
• how PDT is given..the procedure/laser visit

This is a type of laser treatment for neovascular age-related macular degeneration (CNV in ARMD). This p[rogram is in the process of winding down, as the new drugs take over.

A dye is injected intravenously with a simple injection into the patient's arm. The dye passes through the blood to stick to the CNV blood vessels in the retina. 13 minutes later a gentle 'cold' laser is shone into the eye, pointing at the CNV, and this activates the dye. The dye then 'burns' the CNV blood vessels.

The PDT laser is often best combined with anti-growth factor injections, although these are not yet available on the NHS.

Each patient needs an assessment with a fluorescein angiogram every 3 months, with laser at each visit the CNV are active.

• 67% response, although even responders have worse sight
• PDT laser is best combined with anti-growth factor injections
  not yet generally available on the NHS)

• limited response (permission for PDT may be granted for small active lesions in 'only' eyes, with fluid and haemorrhage)

• poor response, may 'rip'
• not generally recommended
• (Oxford, 2006) one patient's case was presented: anti-growth factor injection & then PDT to a small area of CNV..no rip

• the more classic the better the response to laser

• good response, but additional treatment may be needed
  (eg intravitreal drugs)

• good response but needs intravitreal steroid in addition

For the PDT laser to be recommended, patients should have

• 6/60 vision or better in the eye concerned
• classic or predominately classic CNV (>50% classic)
• subfoveal CNV as seen on FFA
• myopic and PIC patients generally receive funding

• optometrists need to refer suspect patients
  
  
• currently suspect patients in the Birmingham area usually need a first assessment at Birmingham and Midland Eye Centre emergency dept, but this arrangement will change. Referral and first visit should be within days.
  
  
• All eligible patients receive funded NHS treatment, but there are very strict guidelines as to the care provided, as per NICE
  guidelines
  
  
• 1% of patients lose vision in the first week after PDT.
  
  
• about 67% of CNV responds; the remainder progress
  
  
• results are better with anti-growth factor injections
  
  
• of those that respond, 20% recurr later
  
  
• smaller areas of CNV get better results
  
  
• the average patient needs 3-4 PDT laser treatments, and has 1-3 extra assessment visits
  
  
• vision does get worse even with laser, but not as bad as without laser (TAP, PubMed, PubMed TAP 1)
  
  
• small lesions do better (does this mean screening might be helpful?)

these are the visual results of PDT

PDT would be best combined with anti-growth factor injections if available

• Patients are asked to come to a special laser clinic
  
  
• the vision is measured, then the pupils dilated
  
  
• sometimes the visit is combined with a fluorescein angiogram, but sometimes the angiogram is carried out the week before
  
  
• if the fluorescein angiogram shows the disease is still active, PDT laser is recommended (although this will change)
  
  
• a brief medical history is taken with blood pressure
  
  
• a canula is inserted into the elbow vein, like having a routine bood test
  
  
• a little saline is injected, and then the patient is attached to a pump and the dye (porphrin) infusion
  
  
• the dye is injected slowly over about 10 minutes
  
  
• anaesthetic eye drops are given
  
  
• at the same time the doctor sets up the laser
  
  
• immediately after the injection the patient walks over to the laser, which is given at the slit lamp
  
  
• after a 3 minute wait
  
  
• the laser is given over 83 seconds (it is simply  a type of bright light shone into the eye through a special contact lens, and it is focused over the area ov CNV)
  
  
• if a large area (or the other eye) needs treatment, the laser is focused on the respective macular area for another 83 seconds
  
  
• the patient will be transfered to the recovery room, be offred a cup of tea, blood pressure is re-recorded, and goes home 30 minutes later
  
  
• the patients MUST BE COMPLETELY COVERED and no part of the skin exposd to sunlight for 48 hours. Otherwise the respective skin will be burnt by the sunlight. Public transport is not ideal if it involves walking outside, although it is fine if combined with a taxi to the station etc.
  
  
• 1% of patients get back pain, 1% lose vision after the laser for a short time and this recovers
  
  
• a blood pressure of less than 140/80mmHg will help to slow down the disease. A high blood pressure will encourage bleeding. Smoking will make it 4 times more likely the CNV will NOT respond to the PDT laser.
  
  
  
• people having PDT using warfarin are more likely to notice macular haemorrhages. Usually the warfarin is need to prevent an even more serious medical problem, and should not usually be stopped. But a LOW BLOOD PRESSURE is likely to reduce the risk of bleeding considerably. Keep BP <140.
  
  
• the next visit is 3 months later for re-assessment, and the procedure repeated if still active
  
  
• 5 treatments may be needed over 15 months, the average is 3 treatments
  
  
• occasionally the PDT activates the CNV leading to loss of more sight, and this can happen over the next few weeks.