Modulation of choroidal neovascularization by subretinal injection of retinal pigment epithelium and polystyrene microbeads.
OBJECTIVE
The study was conducted to create a rapidly developing and reproducible animal model of subretinal choroidal neovascularization (CNV) that allows a time-dependent evaluation of growth dynamics, histopathologic features, and cytokine expression.


METHODS
C57BL/6 and chemoattractant leukocyte protein-2 deficient (DeltaCcl-2) mice were studied. Mice received single or combined subretinal injections of cultured retinal pigment epithelium (RPE; C57BL/6-derived), polystyrene microbeads, or phosphate buffer solution (PBS). Fluorescence angiograms were performed over a period of 3 weeks. Mice were euthanized on post inoculation day 3, 7, 10, 14, or 21, and their eyes were evaluated by light, confocal, and electron microscopy.


RESULTS
CNV membranes occurred in all study groups with an overall incidence of 94.3%. They extended in the subretinal space through central breaks in Bruch's membrane. CNV lesions were characterized by dynamic changes such as initiation, active inflammatory, and involution stages. CNV thickness peaked around PI day 7 and was greater in mice that received combined injections of RPE and microbeads or RPE cells alone. Small lesions developed in the control groups (microbeads or PBS only), in DeltaCcl-2, and old C57BL/6 mice. Variable expression of cytokines and growth factors was detected within the membranes.


CONCLUSIONS
Our murine model represents a reliable approach inducing CNV growth by subretinal injection of either RPE cells alone or RPE cells and microbeads. The development of CNV lesions is a dynamic process that relies in part on macrophage trafficking and age.
Schmack
Ingo
I
Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA.
Berglin
Lennart
L
Nie
Xiaoyan
X
Wen
Jing
J
Kang
Shin J
SJ
Marcus
Adam I
AI
Yang
Hua
H
Lynn
Michael J
MJ
Kapp
Judith A
JA
Grossniklaus
Hans E
HE
D000818:Animals; D002478:Cells, Cultured; D020256:Choroidal Neovascularization / Q000473:pathology*; D005451:Fluorescein Angiography; D005455:Fluorescent Antibody Technique; D007267:Injections; D051379:Mice; D008810:Mice, Inbred C57BL; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011137:Polystyrenes / Q000008:administration & dosage*; D012163:Retinal Detachment / Q000473:pathology; D055213:Retinal Pigment Epithelium / Q000473:pathology* / Q000648:ultrastructure
D011137:Polystyrenes