Agents Used in the Treatment of Conditions of the Eye Chapter 40 Agents Used in the Treatment of Conditions of the Eye

The Eyes Organ of vision Retina Uvea Sclera and cornea Light reacts off the retina

The Eyes Images are transmitted by the optic nerve Interpreted by the brain Anterior and posterior chambers Aqueous humor

Ophthalmic Agents Facilitate eye examinations Treat Infection Inflammation Glaucoma

Sympathomimetic Mydriatics Produce Pupil dilation Increase aqueous humor outflow Decrease formation of aqueous humor

Anticholinergic Mydriatics Block sphincter iris muscle Produce pupil dilation Allow for measurement of refractive errors Cause vision and focus problems

Ophthalmic Anti-infectives Antibiotics Antifungals Antivirals Antiseptics

Ophthalmic Anti-Infectives Eye is susceptible to bacterial, viral, and fungal infections Some require mild therapy Some require aggressive treatment Diagnosis is important Antibiotics Antifungals Antivirals

Antibiotics Monitor for hypersensitivity Systemic therapy should be given in addition to topical agents Topical agents administered as eye drops

Antibiotics Antibiotic eye drops contain agents not usually given systemically Agents are usually a combination of drugs

Antifungal Agents Natamycin treats blepharitis, conjunctivitis, and keratitis Applied to conjunctival sac frequently

Antiviral Agents Can cause severe discomfort May lead to scarring and vision loss if not treated Drugs usually block reproduction of viral agent

Antiviral Agents Alters normal DNA synthesis Most common is herpes simplex and varicella zoster viruses Adverse effects could include burning, irritation, hypersensitivity, pain, photophobia, or toxicity

Nursing Considerations Always monitor effectiveness of therapy Monitor for signs of toxicity Use proper instillation techniques and teach to patients Wash hands Avoid contamination of tip of applicator

Other Eye Agents Local anesthetics Corticosteroids Glaucoma agents

Local Anesthetics Anesthetize the eye Reduce the blinking reflex To remove Chemicals Foreign objects

Corticosteroids Useful for eye allergies Useful as an additive agent in eye infections Reduce Inflammation Pain

Nonsteroidal Anti-inflammatory Agents Four are available for ophthalmic use Inhibits pupil constriction Reduce edema and inflammation Relief of pain May cause hypersensitivity Some may not be used in patients who wear contact lens

Glaucoma Increased intraocular pressure (IOP) Aqueous humor buildup Pressure pushes the vitreous humor against the retina Constant pressure destroys the retina, which leads to blindness

Glaucoma Narrow-angle glaucoma is caused by the iris occluding the anterior chamber structures Dilation of the pupil could cause acute attack Treatment is surgery Creates a new opening Open-angle more common

Glaucoma No change in the chamber angle Local degenerative changes Symptoms appear after severe damage to optic nerve Goal is to decrease production and increase outflow

Antiglaucoma Drugs Reduce the formation of aqueous humor Carbonic anhydrase inhibitors Osmotic diuretics Beta-adrenergic blocking agents

Carbonic Anhydrase Inhibitors Inhibits the enzyme carbonic anhydrase Reduces production of aqueous humor Decreases intraocular pressure Treatment of open-angle glaucoma and pre-operative management of acute narrow-angle glaucoma

Carbonic Anhydrase Inhibitors Used with topical therapy Diuretics Increases excretion of sodium, potassium, bicarbonate, and water

Osmotic Diuretics Rapidly reduces production of aqueous humor Treats acute attacks of narrow-angle glaucoma and preparation of surgery Not for chronic use

Osmotic Diuretics Extreme caution in patients with renal impairment May cause headaches, nausea, and vomiting Given orally or parenterally

Beta-Adrenergic Blocking Agents Applied topically Lowers ocular pressure by reducing formation of aqueous humor Little effect on pupil size or visual acuity

Beta-Adrenergic Blocking Agents Used alone or in combination with other drugs Can be absorbed systemically Can interfere with treatment of patients with airway disease and congestive heart failure

Antiglaucoma Drugs Increase aqueous humor outflow Direct-acting miotic Cholinesterase inhibitors: para-sympathomimetics Prostaglandin-inhibiting agents Sympathomimetics agents

Direct-Acting Miotics Mimic action of acetylcholine Constricts pupil Contracts ciliary muscle Facilitates outflow of aqueous humor

Direct-Acting Miotics Drops, gel, or Ocusert Therapeutic System Adverse effects include reduction in visual acuity, flushing, sweating, gastric distress, diarrhea, and headache

Miotics That Inhibit Cholinesterase Activity Prevents enzymatic destruction of acetylcholine within the eye Inhibits the enzyme cholinesterase Greater acetylcholine activity

Miotics That Inhibit Cholinesterase Activity Production of miosis Contraction of the ciliary muscle More toxic and longer lasting than direct-acting miotics Reserved for use in patients that do not respond to other therapy

Miotics That Inhibit Cholinesterase Activity Adverse effects are both local and systemic Systemic effects - salivation, urinary incontinence, sweating, diarrhea, and muscle weakness

Miotics That Inhibit Cholinesterase Activity Local effects - stinging, burning, lacrimation, lens opacities, and ocular inflammation Monitor for toxicity Antidote is atropine sulfate or pralidoxime chloride

Agents That Effect Formation and Outflow of Aqueous Humor Prostaglandin-inhibiting agents - stimulates outflow by inhibiting prostaglandin synthesis; increases vascular permeability - used prior to eye surgery, open-angle glaucoma, and ocular hypertension - remove contact lenses - latanoprost can cause eye color changes

Agents That Effect Formation and Outflow of Aqueous Humor Sympathomimetic agents - stimulate adrenergic receptors in the eye - reduces aqueous humor production - with extended use, may rebound and increase production

Agents That Effect Formation and Outflow of Aqueous Humor Used in combination with a miotic - use with caution in elderly and patients with hypertension, diabetes, hyperthyroidism, or heart disease - exaggerated effects may occur if taking MAOI’s or other antidepressants - used only in open-angle glaucoma

Nursing Considerations Assess the patients eyes Teach proper administration of eye medications Use eye patches as appropriate Ensure medication is used properly Assess for safety Teach patient to continue treatment as long as prescribed Throw away contaminated medications