Abstract
Purpose :
Retinal Vein Occlusion (RVO) is defined as a vascular retinal disorder that leads to ischemia of the inner retinal layers. RVO can be divided in central (CRVO) and branch (BRVO) based on the veins that are affected. Inflammation has recently been proposed to play a role in the pathogenesis and progress of RVO. This study aims to investigate the role of microglia/macrophages in the course of a murine model of BRVO.
Methods :
BRVO was induced in BALB/c mice with the application of one laser spot on one branch vein of the retina. The presence of microglia/macrophages into the retina was investigated three (3), seven (7), fourteen (14) and twenty-eight (28) days after the induction of BRVO. Histological hematoxylin-eosin staining and immunohistochemical studies against the microglia marker Iba-1 were performed for the investigation of retinal morphology alterations and microglia cells activation, respectively, in control and experimental retinas. Retinal flat mounts were stained with isolectin IB4 and Iba-1 for the labelling of retinal vessels and microglia cells, respectively. Fluorescence activated cell sorting (FACS) was also performed for the investigation of activated macrophages population at different time points after the induction of BRVO.
Results :
Retinal morphology of the laser-subjected retinas was altered compared to the control retinas. Destruction of the outer layers on the laser site and in most of the cases loss of the outer plexiform layer was evident. Immunohistochemical studies on retinal slices and retinal flat mounts showed elevated levels of activated microglia cells into the injured retina 7 days after the BRVO induction. FACS analysis substantiated the immunohistochemical data and revealed elevated levels of activated macrophages in the lasered retinas, compared to the control retinas.
Conclusions :
The present study provides evidence supporting the role of microglia/macrophages in the course of BRVO in mice.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.