A New Quantifiable Blood Retinal Barrier Breakdown Model In Mice

Abstract

Purpose: : Blood retinal barrier (BRB) breakdown that induces macular edema is implicated in many diseases like diabetic retinopathy, branch and central retinal vein occlusion or ocular inflammatory diseases. There are few animal models for this complication. This study was designed to develop a new simplified and improved quantifiable BRB model in mice, and to explore the kinetics of the BRB breakdown in this model.

Methods: : To induce BRB breakdown a 30-gauge needle attached to 1 ml syringe was inserted through the limbus into the lens of adult male C57BL/6 mice. The anterior portion of the lens was aspirated and the needle was removed. To quantify the BRB permeability, Evans blue was injected at a dosage of 45 mg/kg in the Corpus cavernosum penis and detected at 620 nm by spectrophotometry. BRB permeability was quantified 24, 48, 72 and 96 h after lens surgery.

Results: : This method induced a quantifiable increase of the BRB permeability. Indeed BRB permeability increased significantly: 1,8-fold higher Evans Blue leakage at 24 h (n=10 mice, P<0,01) and 48 h (n=6, P<0,05) after lens surgery, compared to controls (n=10 mice). The BRB permeability decreased at 72 and 96 h (no significant differences compare to controls).

Conclusions: : We describe here a simplified and improved method of breaking down and quantifying the BRB in mice. The advantages of this model are: (i) its relative simplicity (ii) economy and (iii) it represents a new interesting tool to investigate for example different treatments of BRB breakdown.

Keywords: edema • pump/barrier function