Programmierter Zelltod (Apoptose) in exzidierten subretinalen Neovaskularisationen

Abstract

Programmed cell death as a regulating pathomechanism was observed in all tissue parts of CNV with variable extension. In patients with AMD, a correlation existed between the length of time that CNV existed before surgery and the incidence of apoptotic cells. Apoptosis was found more frequently in recent CNV than in long-standing lesions. The various activity found in CNV suggests that the success of treatment may depend on the moment of intervention. To characterize the role of apoptosis further inducing and inhibiting factors have to be analyzed.

Verteporfin photodynamic therapy induced apoptosis in choroidal neovascular membranes

“…Previous studies demonstrated the presence of apoptotic retinal pigment epithelial cells, endothelial cells and macrophages in untreated CNV. [18][19][20] We found the same sporadic pattern of expression in cases that were not treated by PDT previously. Wiezorrek and colleagues found apoptosis more frequent in recent CNV than in long standing lesions.…”

“…19 Hinton and co-workers found a high number of apoptotic cells in two of 10 membranes and suggested that apoptosis in active stages of CNV is related to the wound healing process. 18 Additionally, it was postulated that apoptosis may be the mechanism that allows the non-inflammatory resolution of the neovascular tissue into a fibrotic scar. 18 Looking for apoptosis in previously treated membranes we disclosed that 3 days after PDT both collapsed and patent vessels were TUNEL positive.…”

“…18 Additionally, it was postulated that apoptosis may be the mechanism that allows the non-inflammatory resolution of the neovascular tissue into a fibrotic scar. 18 Looking for apoptosis in previously treated membranes we disclosed that 3 days after PDT both collapsed and patent vessels were TUNEL positive. The presence of apoptotic endothelial cells was significantly higher compared to nontreated specimens.…”

“…The TUNEL reaction becomes positive in an intermediate stage of the programmed cell death and is based on labelling of DNA strand breaks. [17][18][19] Thus, regeneration at this stage is not possible. Therefore, it is highly doubtful that apoptotic endothelial cells can regenerate.…”