Figure 5. Nanoparticles (20 nm) are cleared by ocular (blood and lymphatic) circulation. Following periocular administration of 400 µg dose of 20 nm particles to either live (blood and lymphatic circulation present) or dead rats (blood and lymphatic circulation absent), the percent dose remaining at the site of administration was determined 6 h post-dosing. The amount of particles remaining in the periocular tissue was more than 2 fold higher in the dead rats as compared to the live rats. The data are expressed as mean ± SEM for n=4. The asterisk indicates a statistically significant difference between live and dead animals (p<0.05).