Article
Photodynamic-therapy-induced apoptosis in choroidal neovascularization membranes
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Authors
Published: | September 22, 2004 |
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Outline
Text
Objective
Choroidal neovascularization membranes (CNVM) three days after Verteporfin photodynamic therapy (PDT) disclose both occluded as well as patent vessels. At later time points after PDT, however, all vessels are patent and lined by healthy endothelial cells. The present study was performed to distinguish whether these vessels originate from the treated ones or result from neoangiogenesis.
Methods
12 surgically excised CNVM following treatment with PDT were analyzed. Apoptosis was detected by staining with the TUNEL technique and compared with the expression of the panendothelial marker CD 34, CD 105, a marker for activated endothelial cells and the nuclear cell proliferation marker Ki 67.
Results
In CNVM 3 days after PDT, the endothelial cells even of the patent appearing vessels were apoptotic. The endothelial cells in CNVM 1 - 5 months after PDT showed no TUNEL-positive reaction, but a distinct expression of markers for cell proliferation.
Conclusions
PDT induces apoptosis in endothelial cells. The regeneration of apoptotic cells is improbable. Therefore, endothelial cells lining patent vessels in CNVM excised 1 - 5 month after PDT are the result of neoangiogenesis rather than recanalization.