Comparison of Dextran Perfusion and GSI-B4 Isolectin Staining in a Mouse Model of Oxygen-induced Retinopathy

Purpose: Oxygen-induced retinopathy(OIR) is a robust and widely used animal model for the study of retinal neovascularization(NV). Dextran perfusion and Griffonia simplicifolia isolectin B4(GSI-B4) staining are two common methods for examining the occurrence and extent of OIR. This study provides a quantitative comparison of the two for OIR detection.Methods: At postnatal day 7(PN7), fifteen C57 BL / 6J mice were exposed to a 75% hyperoxic condition for 5 days and then returned to room air conditions. At PN17, the mice received intravitreal injection of GSI-B4 Alexa Fluor 568 conjugate. After 10 hours, they were infused with FITC-dextran conjugate via the left ventricle. Retinal flat mounts were photographed by confocal microscopy. Areas with fluorescent signals and the total retinal areas were quantified by Image J software.Results:Both GSI-B4 and dextran detected the peripheral neovascular area. The mean hyper fluorescence area was 0.33 ±0.14% of whole retinal area determined by GSI-B4 staining and 0.25±0.28% determined by dextran perfusion. The difference between the two measures was 0.08%(95% CI:-0.59%,0.43%)..The Pearson correlation coefficient between the two methods was 0.386,P =0.035..The mean coincidence rates were 14.3 ±13.4% and 24.9 ±18.5% for GSI-B4 and dextran staining, respectively.Conclusion:.Both methods can complement each other indemonstrating and quantitatively evaluating retinal NV. A poor agreement was found between the two methods;.GSI-B4 isolectin was more effective than FITC-dextran perfusion in evaluating the extent of retinal NV in a mouse model of OIR.

Purpose： Oxygen-induced retinopathy （OIR） is a robust and widely used animal model for the study of retinal neovascu- larization （NV）. Dextran perfusion and Griffonia simplicifolia isolectin B4 （GSI-B4） staining are two common methods for examining the occurrence and extent of OIR. This study provides a quantitative comparison of the two for OIR detection. Methods： At posmatal day 7 （PN7）, fifteen C57BL/6J mice were exposed to a 75% hyperoxic condition for 5 days and then returned to room air conditions. At PN17, the mice re- ceived intravitreal injection of GSI-B4 Alexa Fluor 568 conjugate. After 10 hours, they were infused with FITC-dextran conjugate via the left ventricle. Retinal flat mounts were pho- tographed by confocal microscopy. Areas with fluorescent signals and the total retinal areas were quantified by Image J soft- ware.Results：Both GSI-B4 and dextran detected the peripheral neo- vascular area. The mean hyper fluorescence area was 0.33±0.14% of whole retinal area determined by GSI-B4 staining and 0.25±0.28% determined by dextran perfusion. The difference between the two measures was 0.08% （95% CI：-0.59%, 0.43% ）. The Pearson correlation coefficient between the two methods was 0.386,P =0.035. The mean coincidence rates were 14.3±13.4% and 24.9 ±18.5% for GSI-B4 and dextran staining, respectively.Conclusion： Both methods can complement each other in demonstrating and quantitatively evaluating retinal NV. A poor agreement was found between the two methods; GSI-B4 isolectin was more effective than FTTC-dextran perfusion in evaluating the extent of retinal NV in a mouse model of OIR.