a

 
What does PDT stand for and how does it work?

AnswerPDT stands for photodynamic therapy.
It is a two stage process involving:
1. Administration of a photosensitizer
2. Activation within target tissue by light of a specific 
wavelength to the photosensitizer, but not strong enough
to cause thermal damage.
The mechanism is though to be generation of oxygen radicals within selective damage to cellular proteins of endothelial cells of choroidal neovascularization.

 

What are the findings of:
a. TAP (Photodynamic Therapy of Subfoveal Choroidal 
    Neovascularization in Age-related Macular Degeneration With 
    Verteporfin) study and 
b. VIP  (Verteporfin in Photodynamic Therapy)  Trial?

Answer
Both studies looked at the effects of photodynamic therapy 
(PDT) on subfoveal choroidal neovascularization.
In the TAP study, the visual deterioration is less in patients 
receiving PDT compared with those receiving placebo at 12 and 24 months after treatment. However, there was no difference between treated and untreated eyes in those with minimally classic lesion (ie. mainly occult lesion). 
VIP study showed that in occult with no classic subfoveal 
choroidal neovascularization, the result of PDT at 12 months showed no statistical differences in visual deterioration 
between treated and untreated groups. However, at 24 
months follow-up, there was a statistical difference in visual 
deterioration between treated and untreated groups with the treated groups having less visual deterioration. 
 

If this patient could not afford PDT (currently costing the patient £1,000 under the National Health Service), what is the alternative treatment?

Answer
TTT

More questions