Table 1.

Different drug absorption and elimination routes in the human eye

Absorption area	Drug
Cornea	Lipophilic drugs
Conjunctiva, sclera	Lipophilic and hydrophilic drugs
From the blood via the blood–ocular barrier	Lipophilic drugs
From the blood via the blood–retinal barrier	Lipophilic drugs
With lacrimal fluid via the trabecular meshwork and Schlemm’s canal	Hydrophilic and lipophilic drugs
With lacrimal fluid via venous blood flow to the front uveal tract	Lipophilic drugs
Out of the vitreous humor via the blood–retinal barrier (back route)	Lipophilic drugs
Out of the vitreous humor via the anterior chamber of the eye (front route)	Hydrophilic and lipophilic drugs