Figure 9. VEGF expression after photocoagulation in RPE-choroid complex. A: The amount of vascular endothelial growth factor (VEGF) transcripts was compared with 18S transcripts (y-axis) expressed in the same samples. Four eyes were assessed at each time point. Values in histogram are means±SEM B-C: Representative samples of PCR fragments (individual ratio VEGF:18S closest to the corresponding mean) were analyzed by 3% agarose gel electrophoresis and visualized by ethidium bromide staining under ultraviolet light for 10–12-week-old mice (B) and 1-year-old mice (C). Prior to laser treatment, VEGF mRNA expression was lower in old control mice versus young control mice (p<0.001). At day 3 after PC, the highest level of VEGF mRNA was 2.7 times higher than the controls in old mice. In young mice the highest level of expression was reached at 16 h after photocoagulation and did not exceed 1.3 times the level observed in controls.