Toxicity of the photosensitizer NPe6 following intravitreal injection.
OBJECTIVE
To determine the retinal toxicity of mono-L-aspartyl chlorin e6 (NPe6) following intravitreal injection.


METHODS
Twelve Dutch-belted rabbits divided into 5 experimental groups (n=2 each) were injected intravitreally with 6.25, 12.5, 25, 50, or 100 microg of NPe6; one control group (n=2) was injected with intravitreal normal saline. One eye in each rabbit was sutured shut to test the effect of light exposure. Fundus photography and electroretinograms were performed before treatment and 2 days, 1 week, and 2 weeks after injection. Animals were euthanized and the eyes enucleated for histopathologic analysis.


RESULTS
After 1 week, 4 uncovered eyes given 50 and 100 microg had central retinal vein occlusion and varying degrees of retinal hemorrhage. RPE proliferation was seen in the covered eyes given 50 or 100 microg. Electroretinograms revealed absent retinal response at 100 microg and mild toxicity at 50 microg, but no change from normal at doses of < or = 25 microg of NPe6.


CONCLUSIONS
Intravitreal doses of < or = 25 microg NPe6 caused little or no apparent toxicity; however, toxicity was significant at doses of 50 microg and 100 microg.
El-Dessouky
E S
ES
LSU Eye Center, Louisiana State University Health Sciences Center School of Medicine, New Orleans, USA.
Moshfeghi
A A
AA
Peyman
G A
GA
Yoneya
S
S
Mori
K
K
Kazi
A A
AA
Moshfeghi
D M
DM
D000818:Animals; D004596:Electroretinography / Q000187:drug effects; D005654:Fundus Oculi; D007267:Injections; D023421:Models, Animal; D017319:Photosensitizing Agents / Q000633:toxicity*; D010857:Pigment Epithelium of Eye / Q000187:drug effects / Q000473:pathology; D011166:Porphyrins / Q000633:toxicity*; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D012166:Retinal Hemorrhage / Q000139:chemically induced* / Q000473:pathology; D012170:Retinal Vein Occlusion / Q000139:chemically induced* / Q000473:pathology; D014822:Vitreous Body / Q000187:drug effects
D017319:Photosensitizing Agents; D011166:Porphyrins; C053434:Talaporfin