“…Although these methods can achieve high drug concentrations in the posterior segment of the vitreous humor, lens, retina, and other ocular tissues, their broad clinical application is limited by potential complications such as tissue damage, infection and injury, and retinal hemorrhage. [8][9][10][11] Drug administration into the anterior segment has been proposed to circumvent these problems. In intraocular administration, drug molecules must diffuse over a long distance from the site of corneal penetration and penetrate the ocular barrier -which consists of the convection flow of the aqueous humor from the ciliary body to Schlemm's canal, together with lacrimal fluid, blood-aqueous humor, retinal blood, and a corneal avascular component -and be specifically absorbed by the retinal pigment epithelium.…”