Abstract
Abstract: :
Purpose:To evaluate the potential of earlier treatment intervals to reduce the risk of visual loss in patients with choroidal neovascularization (CNV) receiving photodynamic therapy. Methods:A prospective, randomized, masked, multi-center phase 3B trial was performed in patients with subfoveal CNV and a predominantly classic component due to age-related macular degeneration (AMD). 200 patients were evaluated by a central angiographic reading center and randomized only after the presence of a predominantly classic lesion type was confirmed in each participant. Patients were randomized 1:1 into two arms: Group A received verteporfin therapy at 2 month-intervals, group B was retreated according to the standard protocol of 3 months during a 6 month follow-up. Treatment indication, parameters and angiographic retreatment criteria within the two arms were similar to the TAP ( Treatment of AMD with PDT) regimen. Visual acuity was measured using the ETDRS protocol, lesion size was documented based on the greatest linear diameter (GLD). Results:All patients in both groups met the inclusion criteria. Patients in group A had a mean age of 72.7 years, in group B of 75.1 years. The mean visual acuity at baseline was balanced between both groups with a mean letter score of 51.3 (A) and 51.2 letters (B) corresponding to a Snellen equivalent of 20/100. Baseline GLD was 1782 +/-503 µm in group A and 2213 +/-554 µm in group B (not statistically significant different). At the 6 month follow-up visit, mean visual acuity decreased by 1.2 lines (6 letters) to 20/126 (45.5 letters) in group A and by 1.4 lines (8 letters) to 20/160 (43 letters) in group B. This difference did not demonstrate statistical significance. The mean GLD in group A increased by 627 µm to 2409 +/-456 µm and by 471 µm to 2684 +/-362 µm in group B which was statistically not significant. Subgroup analysis revealed an increased benefit of treatment in eyes with a GLD 2000 µm in the same group Conclusions: Based on this interims-analysis at 6-month follow-up, shorter treatment intervals of 2 months did not demonstrate any advantage compared to the standard protocol recommending 3 month intervals. No statistically significant difference was found in respect to change in mean visual acuity, mean visual loss or lesion size. A smaller initial lesion size was associated with an improved visual outcome.
Keywords: photodynamic therapy • age-related macular degeneration • choroid: neovascularization