Treatment of AMD with Photodynamic Therapy (TAP)
Purpose of the study:
  • To study the effect of PDT on subfoveal CNV


Method of the study:

  • 609 patients with AMD and subfoveal CNV with a classic component and refracted logMAR visual acuity (VA) between 6/12 and 6/60 (Snellen equivalent) underwent a 2:1 randomisation between treatment and control (sham treatment).
  • Retreatment was applied to zones of persistent or new leakage at 3 monthly visits. 


Duration of follow-up:

  • Follow-up rates were 94% at 12 and 87% at 24 months. 


Results of the study:

  • The frequency of stable (<15 logMAR letters lost) or improved vision in each group was: 12 months - 61% treated, 46% placebo (p<0.001); 24 months - 53% treated, 37% placebo (p<0.001). 
  • At 12 months a visual improvement (15 letters) occurred in 16% treated and 7% placebo patients. 

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  • For predominantly classic lesions the frequency of stable/improved vision was: 

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    • 12 months - 67% treated, 39% placebo (p<0.001)
    • 24 months - 59% treated, 31% placebo (p<0,001).
  • For lesions with no occult component frequencies at 12 months were: 73% treated, 23% placebo (p<0.01). 

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  • Treatment benefit was also shown for secondary endpoints. Average number of treatments in the treated group was 5.6 (3.4 in the first 12 months). 


Potential complications:

  • There were a similar number of deaths and serious adverse events in each group. 
  • <2% of patients were withdrawn due to adverse events. 
  • Commoner in treated patients at 12 months were: transient visual disturbance - 18% treated, 12% placebo; injection site events - 13% treated, 0% placebo; transient photosensitivity reactions - 3% treated, 0% placebo; low back pain - 2% treated, 0% placebo. 
References:
  • TAP study group. Photodynamic therapy of subfoveal choroidal neovascularisation in age-related macular degeneration with verteporfin. One-year results of 2 randomised clinical trials - TAP report 1. Arch Ophthalmol 1999; 117:1329-1345 
  • Zhou C. Mechanisms of tumour necrosis induced by photodynamic therapy. J Photochem Photobiol B 1989; 3: 299-318 
  • Miller JW, Schmidt-Erfurth U, Sickenberg M, et al. Photodynamic therapy with verteporfin for choroidal neovascularisation caused by age-related macular degeneration: results of a single treatment in a phase 1 and 2 study. Arch Ophthalmol 1999;117:1161-1173 
  • Schmidt-Erfurth U, Miller JW, Sickenberg M, et al. Photodynamic therapy with verteporfin for choroidal neovascularization caused by age-related macular degeneration: results of a single treatment in a phase 1 and 2 study. Arch Ophthalmol 1999; 1999; 117:1177-1187 
  • Hart PA, Harding SP. Is it time for a national screening programme for sight-threatening diabetic retinopathy? Editorial Eye 1999; 13:129-130 
  • Wormald R, Evans J, Smeeth L. Photodynamic therapy for neovascular age-related macular degeneration (Cochrane Review). Cochrane Eyes and Vision Group. In: The Cochrane Library, Issue 3, 2000. Oxford: Update Software. http://www.cochrane.co.uk 
  • Evans J, Rooney C, Ashwood F, Dattani J, Wormald R. Blindness and partial sight in England and Wales: April 1990 - March 1991. Health Trends 1996; 28:5-12 
  • Moisseiev J, Alhalel A, Masuri R, Treister G. The impact of the Macular Photocoagulation Study results on the treatment of exudative age-related macular degeneration. Arch Ophthalmol 1995;113:185-189. 
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