Accumulation of photosensitizer ATX-S10 (Na) in experimental corneal neovascularization.
OBJECTIVE
To determine the most appropriate time for laser irradiation to produce selective occlusion of new corneal vessels by photodynamic therapy (PDT) with a new photosensitizer, ATX-S10(Na).


METHODS
The time course of the plasma levels of ATX-S10(Na) and the degree of dye accumulation in the corneal neovascularization after intravenous administration was determined in rabbit eyes. Plasma concentration of ATX-S10(Na) was analyzed by a spectrophotometer. The amount of ATX-S10(Na) in the new corneal vessels was measured by nitrogen-pulsed laser spectrofluorometry. Frozen sections of neovascularized cornea and iris were observed by fluorescence microscopy.


RESULTS
Plasma ATX-S10(Na) concentration was highest 5 minutes after dye injection and rapidly decreased and reached almost zero at 24 hours, indicating its prompt excretion from the body. The amount of ATX-S10(Na) in the new corneal vessels as measured by nitrogen-pulsed laser spectrofluorometry increased and reached maximal level at 2 to 4 hours. Under fluorescence microscopy, the dye was more abundantly localized in the wall of new corneal vessels than in the normal tissue at 2 to 4 hours.


CONCLUSIONS
These results indicate that laser irradiation between 2 and 4 hours after dye injection is appropriate for selective PDT with ATX-S10(Na) for the occlusion of new corneal vessels.
Gohto
Y
Y
Departments of Ophthalmology, Osaka City University School of Medicine, Osaka, Japan.
Obana
A
A
Kaneda
K
K
Nakajima
S
S
Takemura
T
T
Miki
T
T
D000818:Animals; D003315:Cornea / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D016510:Corneal Neovascularization / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D007275:Injections, Intravenous; D008856:Microscopy, Fluorescence; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011166:Porphyrins / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011817:Rabbits; D013050:Spectrometry, Fluorescence
C115550:ATX-S10; D017319:Photosensitizing Agents; D011166:Porphyrins