Fig. 4

Diagrammatic representation of ocular pharmacokinetics. Drugs can enter and exit the eye in a number of ways, including drug absorption through tears in the cornea [1], drug absorption through the sclera and conjunctiva [2], drug distribution from the bloodstream to the anterior segment through BAB [3], and drug elimination through the trabecular meshwork and Schlemm’s canal [4] and from the aqueous humor across the BAB [5]. Moreover, drugs can be directly injected straight into the vitreous [6] or enter the posterior part of the eye through the BRB [7]. Finally, drugs can be eliminated from the vitreous via both posterior [8] and anterior routes [9]. (Solid arrows: entering route; Dotted arrows: route of elimination)