Figure 1.

Intracameral injection of microbeads elevates IOP of mouse eyes. A: An initial injection of microbeads followed by a second injection at 4 weeks (arrow) resulted in a significant elevation of IOP that was maintained for at least 8 weeks (red circles). Mice that received PBS sham injections showed no change in IOP from steady values at week 0 (black circles). B: Elevated IOP reduced the thickness of entire retina as the individual inner nuclear layer (INL), inner plexiform layer (IPL) and ganglion cell layer (GCL). C: In control retinas, GFAP immunofluorescence was confined almost exclusively to astrocytes in the GCL. D: At eight weeks after initial microbead injection, the GFAP labeling was dramatically increased due to expanded expression in Müller cell processes extending across retinal layers. E: Histograms quantify and compare the mean percentage area of GFAP labeling in control and glaucomatous retinas. Measurements were made of fluorescent pixels within a 100 x 100 μm square (in panels in C and D). Three to four area measurements were made and averaged in five control and five microbead-injected retinas. F: The fluorescent intensity profile of GFAP labeling for pixels measured along a single line profile (white lines in panels C and D), shows its upregulation in the IPL and INL of glaucomatous retinas compared to controls, with the largest increase in expression in the IPL. Bars indicate mean value ± SD (in A) and mean ± SEM (applies to panels B and E). *p<0.05; ***p<0.001, Student’s t-test. Scale bars = 50 μm (applies to panels C and D).