A moephologic study of retinal toxicity induced by triamcinolone acetonide vehicles in rabbit eyes.
OBJECTIVE
To evaluate the toxic effects of two triamcinolone acetonide (TA) vehicles on rabbit retina at different volumes.


METHODS
Vehicle A and B were prepared from two TA injections by centrifugation. Thirty-six New Zealand white rabbits were intravitreally injected with vehicle A, B, or balanced saline solution at 0.1 mL or 0.2 mL respectively. The eyes were examined by indirect ophthalmoscope, light microscope, and transmission electron microscope up to week 8 postinjection.


RESULTS
Eyes with vehicle A appeared normal under the ophthalmoscope, but showed disorganization in retinal inner nuclear layer and photoreceptor layer in pathologic analyses. Eyes with vehicle B displayed more significant retinal changes including retinal hemorrhage, vascular narrowing, myelinated fiber edema, retinal necrosis and atrophy, and photoreceptor apoptosis. There was an increase in degree of the above damages as the volume of either vehicle increased.


CONCLUSIONS
Both vehicle A and B caused volume-related toxicity in rabbit retina. The intensity of the toxic effects of different vehicles may differ. Reducing or decanting the vehicles should be considered before intravitreal use of TA injections.
Li
Qian
Q
Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Wang
Jingzhao
J
Yang
Lin
L
Mo
Bin
B
Zeng
Huiyang
H
Wang
Ningli
N
Liu
Wu
W
D000085:Acetates / Q000633:toxicity; D000818:Animals; D019905:Benzyl Alcohol / Q000633:toxicity; D002266:Carboxymethylcellulose Sodium / Q000633:toxicity; D004338:Drug Combinations; D007267:Injections; D008903:Minerals / Q000633:toxicity; D014677:Pharmaceutical Vehicles / Q000633:toxicity*; D011136:Polysorbates / Q000633:toxicity; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000648:ultrastructure; D012164:Retinal Diseases / Q000139:chemically induced* / Q000175:diagnosis; D012965:Sodium Chloride / Q000633:toxicity; D014222:Triamcinolone Acetonide / Q000737:chemistry*; D014822:Vitreous Body
D000085:Acetates; C030660:BSS solution; D004338:Drug Combinations; D008903:Minerals; D014677:Pharmaceutical Vehicles; D011136:Polysorbates; D012965:Sodium Chloride; D014222:Triamcinolone Acetonide; D002266:Carboxymethylcellulose Sodium; D019905:Benzyl Alcohol