The Eyes
Images are transmitted by the optic nerve
Interpreted by the brainAnterior and posterior chambersAqueous humor
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Sympathomimetic MydriaticsProduce
Pupil dilationIncrease aqueous humor outflow
Decrease formation of aqueous humor
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Anticholinergic MydriaticsBlock sphincter iris muscle
Produce pupil dilationAllow for measurement of refractive errors
Cause vision and focus problems
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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
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AntibioticsMonitor for hypersensitivitySystemic 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
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Antifungal AgentsNatamycin treats blepharitis,
conjunctivitis, and keratitisApplied to conjunctival sac
frequently
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Antiviral Agents
Can cause severe discomfortMay lead to scarring and vision
loss if not treatedDrugs usually block reproduction
of viral agent
Antiviral AgentsAlters normal DNA synthesisMost common is herpes
simplex and varicella zoster viruses
Adverse effects could include burning, irritation, hypersensitivity, pain, photophobia, or toxicity
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Nursing ConsiderationsAlways monitor effectiveness of
therapyMonitor for signs of toxicityUse proper instillation techniques
and teach to patientsWash handsAvoid contamination of tip of
applicator
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Local Anesthetics
Anesthetize the eyeReduce the blinking reflex
To removeChemicalsForeign objects
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Corticosteroids Useful for eye allergies Useful as an additive agent in eye
infections Reduce
InflammationPain
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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
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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
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GlaucomaNarrow-angle glaucoma is
caused by the iris occluding the anterior chamber structures
Dilation of the pupil could cause acute attack
Treatment is surgeryCreates a new openingOpen-angle more common
GlaucomaNo change in the chamber angleLocal degenerative changesSymptoms appear after severe
damage to optic nerveGoal is to decrease production
and increase outflow
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Antiglaucoma Drugs
Reduce the formation of aqueous humor Carbonic anhydrase inhibitors Osmotic diureticsBeta-adrenergic blocking agents
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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 InhibitorsUsed with topical therapyDiureticsIncreases excretion of sodium,
potassium, bicarbonate, and water
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Osmotic Diuretics
Rapidly reduces production of aqueous humor
Treats acute attacks of narrow-angle glaucoma and preparation of surgery
Not for chronic use
Osmotic DiureticsExtreme caution in patients with
renal impairmentMay cause headaches, nausea,
and vomitingGiven orally or parenterally
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Beta-Adrenergic Blocking Agents
Applied topicallyLowers ocular pressure by
reducing formation of aqueous humor
Little effect on pupil size or visual acuity
Beta-Adrenergic Blocking AgentsUsed alone or in combination
with other drugsCan be absorbed systemicallyCan interfere with treatment of
patients with airway disease and congestive heart failure
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Antiglaucoma DrugsIncrease aqueous humor outflow
Direct-acting mioticCholinesterase inhibitors: para-sympathomimetics
Prostaglandin-inhibiting agentsSympathomimetics agents
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Direct-Acting MioticsMimic action of acetylcholineConstricts pupilContracts ciliary muscleFacilitates outflow of aqueous
humor
Direct-Acting MioticsDrops, gel, or Ocusert
Therapeutic SystemAdverse effects include reduction
in visual acuity, flushing, sweating, gastric distress, diarrhea, and headache
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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 miosisContraction of the ciliary muscleMore toxic and longer lasting
than direct-acting mioticsReserved for use in patients that
do not respond to other therapy
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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
inflammationMonitor for toxicityAntidote is atropine sulfate or
pralidoxime chloride35
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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
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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
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