Dynamic observation of selective accumulation of a photosensitizer and its photodynamic effects in rat experimental choroidal neovascularization.
OBJECTIVE
The authors investigated the selective accumulation of a photosensitizer, ATX-S10(Na), in experimental choroidal neovascularization (CNV) in rats using a highly sensitive colorchromatic charge coupled device (CCD) camera.


METHODS
To detect the development of experimental CNV in 30 rats, the animals were followed weekly with simultaneous fluorescein and indocyanine green angiography. After injecting ATX-S10(Na), the authors detected fluorescence from the photosensitizer using a highly sensitive color CCD camera. The camera was connected to a surgical microscope, under which rat fundi were observed through a coverglass in contact with the cornea. The retinas were excited with 405-435 nm light, and the light emitted from the photosensitizer passed through a 680-nm bandpass filter before being detected by the CCD camera.


RESULTS
Immediately after injection, fluorescence appeared in the retinal vessels and then the entire retina. Thirty minutes postinjection, the intensity of the fluorescence was still strong from the whole retina, and the CNV was not detected. One hour after injection, retinal fluorescence was weak but still observable; 1.5 hours postinjection, retinal fluorescence was undetectable but fluorescence was strong from the CNV. Under the optimum therapeutic conditions, CNV was effectively occluded.


CONCLUSIONS
ATX-S10(Na) selectively accumulates in the CNV in rats. The optimum therapeutic timing is approximately 1.5 hours postinjection of the dye in this CNV model.
Hikichi
T
T
Department of Ophthalmology, Asahikawa Medical College, Japan. hikichi@asahikawa-med.ac.jp
Mori
F
F
Nakajima
S
S
Takamiya
T A
TA
Takeda
M
M
Sasaki
M
M
Horikawa
Y
Y
Yoshida
A
A
D000818:Animals; D002829:Choroid / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D020256:Choroidal Neovascularization / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D005451:Fluorescein Angiography; D007091:Image Processing, Computer-Assisted; D007208:Indocyanine Green; D008297:Male; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000493:pharmacokinetics*; D011166:Porphyrins / Q000493:pharmacokinetics*; D051381:Rats; D011914:Rats, Inbred BN
C117772:ATX S10Na(II); D017319:Photosensitizing Agents; D011166:Porphyrins; D007208:Indocyanine Green