Abstract
Purpose :
The purpose of this study was to investigate difference between optical coherence tomography angiography (OCTA) image and immunohistochemistry image in visualizing laser-induced choroidal neovascularization (CNV) in mice.
Methods :
CNV was induced by using laser photocoagulation (GYC-2000; NIDEK Co, Gamagori, Aichi, wavelength 532nm) in the left eyes of 20 female C57BL/6J mice aged 6weeks. Laser spot with size of 100µm, pulse duration of 100ms and incident power of 200mW was applied to make rupture of Bruch’s membrane. Animal-dedicated adapter was installed on OCT and OCTA (RS-3000 Advance; NIDEK Co, Gamagori, Aichi, Japan) and CNV images were taken at 5 days after laser photocoagulation. After OCTA test, isolated choroid was fluorescently labeled with markers for endothelial cells (CD31) and pericyte-like scaffold (platelet-derived growth factor receptor β (PDGFRβ), αsmooth muscle actin (α-SMA) and collagen 1). Area measurements of CNV lesion and pericyte-like scaffold lesion were compared enface OCTA with immunolabeling experiment of choroidal flatmount.
Results :
Area measurements of CNV lesion between enface OCTA and immunolabeling experiment of choroidal flatmount were significantly different. Area measurements of CNV lesion taken from immunolabeling experiment of choroidal flatmounts were larger than ones from enface OCTA. CNV lesion beneath outer edge of pericyte-like scaffold was undetectable as dark halo lesion by enface OCTA but this lesion was detectable as blood signals by cross-sectional OCTA and was stained with CD31. Outer edge of pericyte-like scaffold seemed to develop subretinal fibrosis and differentiation into myofibroblasts by immunolabeling experiments.
Conclusions :
Enface OCTA was not able to detect the whole of laser-induced CNV in mice. CNV lesion undetectable by enface OCTA was beneath outer edge of pericyte-like scaffold developed fibrosis. Because of the OCTA artifact occurred by fibrosis, OCTA have the potential to underestimate CNV.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.