Glaucoma

  1. General information
    1. Characterized by increased intraocular pressure resulting in progressive loss of vision; may cause blindness if not recognized and treated
    2. Risk factors: age over 40, diabetes, hypertension, heredity; history of previous eye surgery, trauma, or inflammation
    3. Types
      1. Chronic (open-angle) glaucoma: most common form, due to obstruction of the outflow of aqueous humor, in trabecular meshwork or canal of Schlemm
      2. Acute (closed-angle) glaucoma: due to forward displacement of the iris against the cornea, obstructing the outflow of the aqueous humor; occurs suddenly and is an emergency situation; if untreated, blindness will result
      3. Chronic (closed-angle) glaucoma: similar to acute (closed-angle) glaucoma, with the potential for an acute attack
    4. Early detection is very important; regular eye exams including tonometry for persons over age 40 is recommended.
  2. Medical management
    1. Chronic (open-angle) glaucoma
      1. Drug therapy: one or a combination of the following
        1. miotic eyedrops (pilocarpine) to increase outflow of aqueous humor
        2. epinephrine eyedrops to decrease aqueous humor production and increase outflow
        3. acetazolamide (Diamox): carbonic anhydrase inhibitor to decrease aqueous humor production
        4. timolol maleate (Timoptic): topical beta-adrenergic blocker to decrease intraocular pressure
      2. Surgery (if no improvement with drugs)
        1. filtering procedure (trabeculectomy, trephining) to create artificial openings for the outflow of aqueous humor
        2. laser trabeculoplasty: noninvasive procedure performed with argon laser that can be done on an outpatient basis; produces similar results as trabeculectomy
    2. Acute (closed-angle) glaucoma
      1. Drug therapy (before surgery)
        1. miotic eyedrops (e.g., pilocarpine) to cause pupil to contract and draw iris away from cornea
        2. osmotic agents (e.g., glycerin [oral], mannitol [IV]) to decrease intraocular pressure
        3. narcotic analgesics for pain
      2. Surgery
        1. peripheral iridectomy: portion of the iris is excised to facilitate outflow of aqueous humor
        2. argon laser beam surgery: noninvasive procedure using laser that produces same effect as iridectomy; done on an outpatient basis
        3. iridectomy usually performed on second eye later since a large number of clients have an acute attack in the other eye
    3. Chronic (closed-angle) glaucoma
      1. Drug therapy: miotics (pilocarpine)
      2. Surgery: bilateral peripheral iridectomy to prevent acute attacks
  3. Assessment findings
    1. Chronic (open-angle) glaucoma: symptoms develop slowly; impaired peripheral vision (tunnel vision); loss of central vision if unarrested; mild discomfort in the eyes; halos around lights
    2. Acute (closed-angle) glaucoma: severe eye pain; blurred, cloudy vision; halos around lights; nausea and vomiting; steamy cornea; moderate pupillary dilation
    3. Chronic (closed-angle) glaucoma: transient blurred vision; slight eye pain; halos around lights
    4. Diagnostic tests
      1. Visual acuity: reduced
      2. Tonometry: reading of 24-32 mm Hg suggests glaucoma; may be 50 mm Hg or more in acute (closed-angle) glaucoma
      3. Ophthalmoscopic exam: reveals narrowing of small vessels of optic disk, cupping of optic disk
      4. Perimetry: reveals defects in visual fields
      5. Gonioscopy: examine angle of anterior chamber
  4. Nursing interventions
    1. Administer medications as ordered.
    2. Provide quiet, dark environment.
    3. Maintain accurate I&O with the use of osmotic agents.
    4. Prepare the client for surgery if indicated.
    5. Provide post-op care (see Cataract Surgery).
    6. Provide client teaching and discharge planning concerning
      1. Self-administration of eyedrops
      2. Need to avoid stooping, heavy lifting, or pushing, emotional upsets, excessive fluid intake, constrictive clothing around the neck
      3. Need to avoid the use of antihistamines or sympathomimetic drugs (found in cold preparations) in closed-angle glaucoma since they may cause mydriasis
      4. Importance of follow-up care
      5. Need to wear Medic-Alert tag

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