7. Glaucoma (acute and chronic): increased intraocular pressure; second most common cause of blindness.
1. Pathophysiology:
1. Acute (closed-angle)-impaired passage of aqueous humor into the circular canal of Schlemm due to closure of the angle between the cornea and the iris. Medical emergency; requires surgery.
2. Chronic (open-angle)-degenerative changes in trabecular meshwork; local obstruction of aqueous humor between the anterior chamber and the canal. Most common; treated with medication (miotics, carbonic anhydrase inhibitors).
3. Secondary-in some cases neovascularization (new vessels) may form; blocks passage of aqueous humor (uveitis, trauma, drugs, diabetes, retinal vein occlusion).
4. Untreated: imbalance between rate of secretion of intraocular fluids and rate of absorption of aqueous humor-increased intraocular pressures-decreased peripheral vision-corneal edema-halos and blurring of vision-blindness.
2. Risk factors-unknown, but associated with:
1. Emotional disturbances.
2. Hereditary factors.
3. Allergies.
4. Vasomotor disturbances.
3. Assessment:
1. Subjective data:
1. Acute (closed-angle):
1. Pain: severe, in and around eyes.
2. Rainbow halos around lights.
3. Blurring of vision.
4. Nausea, vomiting.
2. Chronic (open-angle):
1. Eyes tire easily.
2. Loss of peripheral vision.
3. Dull, morning headache.
2. Objective data:
1. Corneal edema.
2. Decreased peripheral vision.
3. Increased cupping of optic disc.
4. Tonometry-pressures >22 mm Hg.
5. Pupils: dilated.
6. Redness of eye.
4. Analysis/nursing diagnosis:
1. Visual sensory/perceptual alterations related to increased intraocular pressure.
2. Pain related to sudden increase in intraocular pressure.
3. Risk for injury related to blindness.
4. Impaired physical mobility related to impaired vision.
5. Nursing care plan/implementation:
1. Goal: reduce intraocular pressure.
1. Activity: bed rest.
2. Position: semi-Fowler’s.
3. Medications as ordered:
1. Miotics (pilocarpine, carbachol); may not be effective with intraocular pressure (IOP) >40 mm Hg.
2. Carbonic anhydrase inhibitors (acetazolamide [Diamox]).
3. Anticholinesterase (demecarium bromide [Humorsol]) to facilitate outflow of aqueous humor.
4. Ophthalmic beta blockers (timolol) to decrease IOP.
2. Goal: provide emotional support.
1. Place personal objects within field of vision.
2. Assist with activities.
3. Encourage verbalization of concerns, fears of blindness, loss of independence.
3. Goal: health teaching.
1. Prevent increased IOP by avoiding:
1. Anger, excitement, worry.
2. Constrictive clothing.
3. Heavy lifting.
4. Excessive fluid intake.
5. Atropine or other mydriatics that cause dilation.
6. Straining at stool.
7. Eye strain.
2. Relaxation techniques; stress management if indicated.
3. Prepare for surgical intervention, if ordered: laser trabeculoplasty, trabeculectomy (filtering), laser peripheral iridotomy.
4. Medications: purpose, dosage, frequency; eyedrop installation-(1) wash hands; (2) head back, expose conjunctiva of lower lid, instill in center without touching eyelashes or eye; (3) close eyes gently, apply slight pressure to corner of eye to decrease systemic absorption; (4) wait at least 2 minutes before instilling a second eyedrop medication; have extra bottle in case of breakage or loss.
5. Activity: moderate exercise-walking.
6. Safety measures: eye protection (shield or glasses); Medic Alert band or tag; avoid driving 1-2 hours after instilling miotics.
7. Community resources as necessary.
6. Evaluation/outcome criteria:
1. Eyesight preserved if possible
2. Intraocular pressure lowered (<22 mm Hg).
3. Continues medical supervision for life-reports reappearance of symptoms immediately.