Photodynamic therapy for ARMD

Results of a randomised, double masked placebo controlled trial involving 609 patients at 22 centres in North America and Europe showed that patients with the sight threatening “wet” form of age related macular degeneration (ARMD), treated with photodynamic therapy (PDT), were more likely to have stable vision (defined as a loss of less than three lines of vision on a standard eye chart) or improved vision compared with placebo treated patients. These results are from the initial analysis of the 12 month follow up of an ongoing 2 year study. Statistical significance was at a p value of 0.0002. Patients treated with PDT were 34% more likely to retain their vision over the 12 month period compared with the placebo group, and 16% were more likely to experience an improvement in their vision compared with 7% of placebo treated patients. The treatment may show benefit over other forms of treatment such as conventional laser therapy because associated tissue damage is limited. Indeed, this may be suggested by the beneficial results on secondary end points such as contrast sensitivity and lesion growth.

Wet ARMD accounts for 15% of all cases of ARMD and 90% of severe visual loss from ARMD—that is, it is the most visually disabling form of the disease. Up to 50 000 new cases of wet ARMD occur in the UK with 16 000 new registrations for blind or partial sighted registration.

In the current study, PDT appeared to be very well tolerated with less than 2% of the patients so far treated withdrawing from the study. Side effects included reactions at the injection site, transient mild to moderate decrease in vision (in 2% of treated patients), and 24 hour duration of photosensitivity. Multiple treatments appeared to be necessary to achieve …