Choroidal neovascular membranes after photodynamic therapy: ultrastructural analysis of two surgically excised membranes.
OBJECTIVE
To report on the ultrastructural electron microscopic findings of two surgically excised subfoveal choroidal neovascular membranes (CNV) that had undergone photodynamic therapy (PDT).


METHODS
Two patients underwent PDT because of subfoveal neovascular membranes (CNV). Due to enlargement of the CNV seen on fluorescein angiography three months after PDT, one patient underwent surgical excision of the membrane; the other patient underwent both surgical membrane excision combined with macular translocation one month after PDT. The membranes were examined under the transmission electron microscope (TEM).


RESULTS
The membranes were composed of a core and a rim, the latter being mainly composed of fibrin and collagen fibrils. The core was preeminently composed of endothelium-lined vascular channels associated with retinal epithelium cells. The endothelial cells of blood vessels appeared well-preserved.


CONCLUSIONS
The lack of histological signs of recanalization and vascular thrombosis may indicate that in our cases the enlargement of the CNVs seen on fluorescein angiography three months and one month respectively after PDT may originate mainly from reproliferation of choroidal vessels rather than recanalization of previously occluded vessels.
Gremigni
E
E
Eye Surgery Clinic, Santa Chiara Hospital, Pisa - Italy.
Falleni
A
A
Belting
C
C
Di Bartolo
E
E
Rizzo
S
S
D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000098:blood supply / Q000648:ultrastructure; D020256:Choroidal Neovascularization / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D004730:Endothelium, Vascular / Q000648:ultrastructure; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D008566:Membranes / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D013508:Ophthalmologic Surgical Procedures; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D010857:Pigment Epithelium of Eye / Q000648:ultrastructure; D011166:Porphyrins / Q000627:therapeutic use; D012008:Recurrence; D000077362:Verteporfin
D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin