title: Ocular pharmacology.
abstract: Ophthalmic diseases include both those analogous to systemic diseases (eg, inflammation, infection, neuronal degeneration) and not analogous (eg, cataract, myopia). Many anterior segment diseases are treated pharmacologically through eye drops, which have an implied therapeutic index of local therapy. Unlike oral dosage forms administered for systemic diseases, eyedrops require patients not only to adhere to treatment, but to be able to accurately perform-ie, instill drops correctly. Anatomical and physiological barriers make topical delivery to the anterior chamber challenging-in some cases more challenging than absorption through the skin, nasal passages, or gut. Treatment of the posterior segment (eg, vitreous, retina, choroid, and optic nerve) is more challenging due to additional barriers. Recently, intravitreal injections have become a standard of care with biologics for the treatment of macular degeneration and other diseases. Although the eye has esterases, hydroxylases, and transporters, it has relatively little CYP450 enzymes. Because it is challenging to obtain drug concentrations at the target site, ocular clinical pharmacokinetics, and thus pharmacokinetic-pharmacodynamic interactions, are rarely available. Ophthalmic pharmaceuticals require consideration of solubility, physiological pH, and osmolarity, as well as sterility and stability, which in turn requires optimal pharmaceutics. Although applied locally, ocular medications may be absorbed systemically, which results in morbidity and mortality (eg, systemic hypotension, bronchospasm, and bradycardia).
authors.affiliation: PharmaLogic Development, Inc., San Rafael, CA, USA.|Departments of Pharmacology and Ophthalmology, University of California, Davis, CA, USA.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Novack
authors.affiliation: Department of Ophthalmology, University of Maryland, Baltimore, MD, USA.|Department of Ophthalmology, University of Michigan, Ann Arbor, MI, USA.|Department of Ophthalmology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Alan L
authors.initials: AL
authors.lastname: Robin
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems; D005128:Eye Diseases / Q000188:drug therapy*; D006801:Humans
keywords: glaucoma; macular degeneration; ophthalmology; pharmacology