Photodynamic effects on choroidal neovascularization and physiological choroid.
OBJECTIVE
To evaluate the effect of photodynamic therapy (PDT) on perfusion and vascular integrity of choroidal neovascularization (CNV) and collateral physiological choroid.


METHODS
In a prospective clinical trial, patients with subfoveal CNV were treated with PDT and verteporfin. Indocyanine green angiography (ICG-A), using a confocal laser scanning system with tomographic sections, was performed continuously 1 week before and 1, 4, and 12 weeks after and a mean long-term follow-up of 16.5 months after the final PDT. Vascular changes were localized tomographically and quantified on the level of the CNV and collateral choroid according to early lesion size, late hyperfluorescence, and persistence or recurrence. Data were analyzed separately from 38 eyes in a single- and 12 eyes in a multiple-treatment regimen.


RESULTS
CNV lesions were significantly reduced in size and late hyperfluorescence. However, 54% of lesions primarily demonstrated persistence, typically of the choroidal feeding complex, which was only detectable by ICG-A. Regrowth from the feeding vessel occurred regularly, but did not reach baseline dimensions. Collateral choroid exposed to photoactivation exhibited choriocapillary occlusion. Progressive recanalization was documented within 4 to 12 weeks after both single and multiple PDT. Residual changes in the choroidal filling pattern often persisted during long-term follow-up.


CONCLUSIONS
Tomographic ICG-A after PDT reveals persistence of CNV and/or the feeder vessel and a reduction in perfusion within the entire photosensitized area, including the surrounding choroid. Repair mechanisms occur slowly in neovascular and normal choroidal structures.
Schmidt-Erfurth
Ursula
U
Eye Hospital, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany. uschmidterfurth@ophtha.mu-luebeck.de
Michels
Stephan
S
Barbazetto
Irene
I
Laqua
Horst
H
D002196:Capillaries / Q000502:physiology; D002829:Choroid / Q000098:blood supply* / Q000473:pathology; D020256:Choroidal Neovascularization / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D005451:Fluorescein Angiography; D006801:Humans; D007208:Indocyanine Green; D007834:Lasers; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011166:Porphyrins / Q000627:therapeutic use*; D011446:Prospective Studies; D012008:Recurrence; D014054:Tomography; D000077362:Verteporfin
D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin; D007208:Indocyanine Green