Chapter 47: Eye & Ear Disorder Drug Therapy

Eye & Ear Disorder Drug Therapy explores the pharmacology and pathophysiology of eye and ear disorders, applying the nursing process to the management of sensory perception issues. It begins with an anatomical review of the eye, describing its three layers—the cornea and sclera, the uveal tract (choroid, iris, ciliary body), and the retina—and explains the critical dynamics of aqueous humor production and drainage through the trabecular meshwork. The text details common ocular infections such as bacterial conjunctivitis, blepharitis, and keratitis, alongside treatments involving topical anti-infectives like ciprofloxacin and gentamicin. A significant portion is dedicated to Age-Related Macular Degeneration (AMD), distinguishing between the slow-progressing dry form and the rapid, severe wet (neovascular) form, which is treated with intravitreal VEGF inhibitors. The chapter provides an in-depth analysis of Glaucoma, a group of optic neuropathies driven by increased Intraocular Pressure (IOP). It differentiates between chronic open-angle glaucoma and the medical emergency of angle-closure glaucoma. Pharmacologic management of glaucoma is categorized by mechanism of action: Prostaglandin Analogues (e.g., latanoprost) increase uveoscleral outflow but may cause permanent iris darkening and eyelash hypertrichosis; Beta-Adrenergic Blockers (e.g., timolol) reduce aqueous production but require monitoring for systemic cardiac (bradycardia) and respiratory (bronchospasm) effects; Alpha-Adrenergic Agonists (e.g., brimonidine) and Carbonic Anhydrase Inhibitors (e.g., acetazolamide) further lower IOP; and Cholinergic Agents (miotics like pilocarpine) induce miosis to widen the drainage angle. The chapter also covers diagnostic drugs like fluorescein stains and anesthetics, as well as mydriatics and cycloplegics (e.g., atropine) used for dilation, noting their contraindication in angle-closure glaucoma. Transitioning to otic disorders, the text reviews the external, middle, and inner ear, focusing on Acute Otitis Media (AOM) and Otitis Externa (swimmer's ear). Management strategies include systemic antibiotics (amoxicillin) for AOM and topical fluoroquinolones for OE, often utilizing ear wicks for delivery in edematous canals. Cerumenolytics like carbamide peroxide are discussed for wax impaction. The chapter concludes with essential patient teaching on administration techniques to prevent systemic absorption of eye drops and the risks of ototoxicity with perforated eardrums.