Consequences of verteporfin photodynamic therapy on choroidal neovascular membranes.
OBJECTIVE
To examine the impact of photodynamic therapy (PDT) on angiogenesis in human choroidal neovascular membranes with respect to vascular endothelial growth factor (VEGF) expression, proliferation, and vascularization.


METHODS
Retrospective review of an interventional case series of 50 patients (50 eyes) who underwent removal of choroidal neovascular membranes. Choroidal neovascularization was secondary to age-related macular degeneration. Twenty patients were treated with PDT 3 to 655 days before surgery. Choroidal neovascular membranes were stained for CD34, CD105, Ki-67, cytokeratin 18, and VEGF. Thirty choroidal neovascular membranes secondary to age-related macular degeneration without previous treatment were used as controls.


RESULTS
Specimens without pretreatment disclosed varying degrees of vascularization, proliferative activity, and VEGF expression by different cells. Specimens treated with PDT 3 days earlier showed mostly occluded vessels, damaged endothelial cells, and low proliferative activity. In contrast, specimens excised at later time points after PDT were highly vascularized and proliferating. This chronology was associated with an impressive VEGF immunoreactivity unique to retinal pigment epithelial cells shortly after PDT that also shifted to other cells at later time points.


CONCLUSIONS
Photodynamic therapy induces selective vascular damage in choroidal neovascular membranes. The effectiveness and selectivity of this treatment, however, seem to be jeopardized by a rebound effect initiated by enhanced VEGF expression in retinal pigment epithelial cells.
Tatar
Olcay
O
University Eye Clinic at the Centre for Ophthalmology, Eberhard-Karls-University, Tübingen, Germany.
Kaiserling
Edwin
E
Adam
Annemarie
A
Gelisken
Faik
F
Shinoda
Kei
K
Völker
Michael
M
Lafaut
Bart A
BA
Bartz-Schmidt
Karl Ulrich
KU
Grisanti
Salvatore
S
D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism; D049109:Cell Proliferation; D002829:Choroid / Q000098:blood supply; D020256:Choroidal Neovascularization / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D000071063:Endoglin; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007633:Keratins / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008566:Membranes; D008875:Middle Aged; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011166:Porphyrins / Q000627:therapeutic use*; D011956:Receptors, Cell Surface / Q000378:metabolism; D012189:Retrospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D000077362:Verteporfin
D015703:Antigens, CD; D018952:Antigens, CD34; C064206:ENG protein, human; D000071063:Endoglin; D019394:Ki-67 Antigen; D017319:Photosensitizing Agents; D011166:Porphyrins; D011956:Receptors, Cell Surface; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000077362:Verteporfin; D007633:Keratins