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Cataract

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Description 
  1. A cataract is an opacity of the lens that distorts image projected onto the retina and that can progress to blindness. 
  2. The lens opacity reduces visual acuity. As the eye ages, the lens loses water and increases in size and density, causing compression of lens fibers. A cataract then forms as oxygen uptake is reduced, water content decreases, calcium content increases, and soluble protein becomes insoluble. 
  3. Intervention is indicated when visual acuity has been reduced to a level that the client finds to be unacceptable or adversely affects lifestyle. 
  4. Over time, compression of lens fibers causes a painless, progressive loss of transparency that is often bilateral. The rate of cataract formation in each eye is seldom identical. 

Causes

Cataracts have several causes and may be age-related, present at birth, or formed as a result of trauma or exposure to a toxic substance. The most common cataract is age-related (senile cataract). Traumatic cataracts develop after a foreign body injures the lens. Complicated cataracts develop as secondary effects in patients with metabolic disorders (e.g., diabetes mellitus), radiation damage (x-ray or sunlight), or eye inflammation or disease (e.g., glaucoma, retinitis pigmentosa, detached retina, recurrent uveitis). Toxic cataracts result from drug or chemical toxicity. Congenital cataracts are caused by maternal infection (e.g., German measles, mumps, hepatitis) during the first trimester of pregnancy.

Complications
Complications may include retinal disorders, pupillary block, adhesions, acute glaucoma, macular edema, and retinal detachment. Following extracapsular cataract extraction, the posterior capsule may become opacified. This condition, called a secondary membrane or after-cataract, occurs when subcapsular lens epithelial cells regenerate lens fibers, which obstruct vision. After-cataract is treated by yttrium-aluminum-garnet (YAG) laser treatment to the affected tissue. Without surgery, a cataract eventually causes complete vision loss.


Assessment
  1. Opaque or cloudy white pupil
  2. Gradual loss of vision
  3. Blurred vision
  4. Decreased color perception
  5. Vision that is better in dim light with pupil dilation
  6. Photophobia
  7. Absence of the red reflex



Primary Nursing Diagnosis
  • Sensory and perceptual alterations (visual) related to decreased visual acuity
Other Diagnoses that may occur in Nursing Care Plans For Cataract
  • Anxiety
  • Deficient knowledge (diagnosis and treatment)
  • Risk for infection
  • Risk for injury


Diagnostic Evaluation
  • General Comments: No specific laboratory tests identify cataracts. Diagnosis is made by history, visual acuity test, and direct ophthalmoscopic exam.
  • Ophthalmoscopy or slit lamp examination may reveal a dark area in the red reflex. Ophthalmoscopy or slit lamp examination is a microscopic instrument that allows detailed visualization of anterior segment of eye to identify lens opacities and other eye abnormalities

Medical Management

There is no medical treatment for cataracts, although use of vitamin C and E and beta-carotene is being investigated. Glasses or contact, bifocal, or magnifying lenses may improve vision. Mydriatics can be used short term, but glare is increased.

Surgical Management
  • Surgical removal of the opacified lens is the only cure for cataracts. The lens can be removed when the visual deficit is 20/40.
  • If cataracts occur bilaterally, the more advanced cataract is removed first.
  • Extracapsular cataract extraction, the most common procedure, removes the anterior lens capsule and cortex, leaving the posterior capsule intact. A posterior chamber intraocular lens is implanted where the patient’s own lens used to be.
  • Intracapsular cataract extraction removes the entire lens within the intact capsule. An intraocular lens is implanted in either the anterior or the posterior chamber, or the visual deficit is corrected with contact lenses or cataract glasses.
  • Complications may include retinal disorders, pupillary block, adhesions, acute glaucoma, macular edema, and retinal detachment. Following extracapsular cataract extraction, the posterior capsule may become opacified. This condition, called a secondary membrane or after-cataract, occurs when subcapsular lens epithelial cells regenerate lens fibers, which obstruct vision. After-cataract is treated by yttrium-aluminum-garnet (YAG) laser treatment to the affected tissue.

Extracapsular cataract extraction


Pharmacologic Highlights
  • Acetazolamide a carbonic anhydrase inhibitor is used to reduce intraocular pressure by inhibiting times a day inhibitor formation of hydrogen and bicarbonate ions.
  • Phenylephrine a Sympathomimetic agent causes abnormal dilation of the pupil constriction of conjunctival arteries.
  • Other Medications: Postoperatively, medications are prescribed to reduce infection (gentamicin or neomycin) and to reduce inflammation (dexamethasone), taking the form of eye drops. Acetaminophen is prescribed for mild discomfort; tropicamide is prescribed to induce ciliary paralysis.

Nursing Interventions

  1. If nursing care is provided in the patient’s home, structure the environment with conducive lighting and reduce fall hazards.
  2. Suggest magnifying glasses and large-print books. Explain that sunglasses and soft lighting can reduce glare.
  3. Assist the patient with the actions of daily living as needed to remedy any self-care deficit.
  4. Encourage the patient to verbalize or keep a log on his or her fears and anxiety about visual loss or impending surgery.
  5. Help plan events to solve the problems with social isolation.

Documentation Guidelines
  • Presence of complications: Eye discharge, pain, vital sign alterations
  • Response to eye medication
  • Reaction to supine position

Discharge and Home Healthcare Guidelines
  • Be sure the patient understands all medications, including dosage, route, action, adverse effects,  and need for postoperative evaluation, usually the next day, by the eye surgeon. Review installation technique of eye drops into the conjunctival sac. Teach the patient to avoid over-the-counter medications, particularly those with aspirin.
  • Instruct the patient to report any bleeding, yellow-green drainage, pain, visual losses, nausea, vomiting, tearing, photophobia, or seeing bright flashes of light. Instruct the patient to avoid activities that increase intraocular pressure such as bending at the waist, sleeping on the operativeside, straining with bowel movements, lifting more than 15 pounds, sneezing, coughing, or vomiting. Instruct the patient to wear a shield over the operative eye at night to prevent accidental injury to the eye during sleep and to wear glasses during the day to prevent accidental injury to the eye while awake. Recommend that the patient avoid reading for some time after surgery to reduce eye strain and unnecessary movement so that maximal healing occurs.
  • Advise the patient not to shampoo for several days after surgery. The face should be held away from the shower head with the head tilted back so that water spray and soap avoid contact with the eye.
HOME HEALTH TEACHING
  • Vacuuming should be avoided because of the forward flexion and rapid, jerky movement required.
  • Driving, sports, and machine operation can be resumed when permission is granted by the eye surgeon.
  • Clients fitted with cataract eyeglasses need information about altered spatial perception. The eyeglasses should be first used when the patient is seated, until the patient adjusts to the distortion.
  • Instruct the client to look through the center of the corrective lenses and to turn the head, rather than only the eyes, when looking to the side. Clear vision is possible only through the center of the lens. Hand-eye coordination movements must be practiced with assistance and relearned because of the altered spatial perceptions.





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