Abstract
Purpose: :
To evaluate the impact of lesion size on the observed growth of choroidal neovascularization (CNV) following the first application of Verteporfin photodynamic therapy ( VPDT).
Methods: :
A retrospective study of consecutive patients with subfoveal classic CNVor predominantly classic CNV undergoing first VPDT according to TAP protocol between June 2005 and September 2005. Patients were classified into 2 groups according to baseline greatest linear dimension (GLD) at the time of VPDT monotherapy. Group 1 comprised patients with lesion GLD <2000 µm and Group 2, patients with lesion GLD ≥ 2000 µm. Difference between the mean lesion GLD at baseline and at 3 months post treatment were investigated for clinical significance using the paired t-test.
Results: :
Three months after first VPDT treatment, Group 1 (n=16) showed meanchange in GLD from 1380.25 µm to 2031.25 µm, whilst Group 2 (n=26) showed mean change of 2909.26 µm to 3023.07 µm. Data of mean percentage change in GLD for Group 1 showed 51.97% increase in the lesion size [95% CI, 22.93-81.01%] in comparison to Group 2 which showed only 5.8% increase in the lesion [95% CI, -9.65 - 21.61%]. Comparison of the mean percentage change in GLD between the two groups showed a statistically significant difference (P = 0.003).
Conclusions: :
Our study demonstrates that following the first application of VPDT, smaller lesions enlarge disproportionately more than larger lesions. This is an important pitfall to be aware of when using VPDT monotherapy for small, predominantly classic, lesions as they can be more aggressive.
Keywords: age-related macular degeneration • photodynamic therapy