Rabbit retinal neovascularization induced by latex angiogenic-derived fraction: an experimental model.
OBJECTIVE
To create a retinal neovascularization experimental model using intravitreal injection of microspheres loaded with latex-derived angiogenic fraction.


METHODS
Thirty-two albino New Zealand rabbits, divided in 4 groups of 8 animals, were enrolled in this study. Rabbits in groups I, II, and III received one intravitreal injection of PLGA (L-lactide-co-glycolide) microspheres with 10, 30, and 50 microg of latex-derived angiogenic fraction into their right eyes, respectively, and group IV received 0.1 ml of microspheres without the angiogenic fraction. Weekly follow-up with ophthalmoscopy and fluorescein angiography was performed; the rabbits were sacrificed in the 4th week and their eyes processed for light microscopy.


RESULTS
All eyes from group I demonstrated increased retinal vascular tortuosity, observed from 14 days after injection and maintained for 28 days, otherwise without new vessels detection. All group II eyes showed vascular changes similar to group I. Fifty percent of the eyes from group II rabbits developed retinal neovascularization 21 days after injection. All eyes from group III demonstrated significant vascular tortuosity and retinal new vessels 2 weeks after injection, progressing to fibrovascular proliferation and tractional retinal detachment. No vascular changes or retinal new vessels were observed in group IV eyes. Light microscopy confirmed the existence of new vessels previously seen on fluorescein angiography, in retinal sections adjacent to the optic disc, not observed in sections at the same area in the control group.


CONCLUSIONS
Thirty- and 50-microg microspheres containing latex-derived angiogenic fraction injected into the vitreous cavity induced retinal neovascularization in rabbits.
Sampaio
R B
RB
Department of Ophthalmology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Mendonca
R J
RJ
Simioni
A R
AR
Costa
R A
RA
Siqueira
R C
RC
Correa
V M
VM
Tedesco
A C
AC
Haddad
A
A
Coutinho Netto
J
J
Jorge
R
R
D043925:Angiogenesis Inducing Agents / Q000633:toxicity*; D000818:Animals; D004195:Disease Models, Animal; D004337:Drug Carriers; D005260:Female; D005451:Fluorescein Angiography; D019344:Lactic Acid; D007840:Latex / Q000633:toxicity*; D008863:Microspheres; D009887:Ophthalmoscopy; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D015861:Retinal Neovascularization / Q000139:chemically induced* / Q000175:diagnosis; D012171:Retinal Vessels / Q000187:drug effects* / Q000473:pathology
D043925:Angiogenesis Inducing Agents; D004337:Drug Carriers; D007840:Latex; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid