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Caratracts

5 min read

References:

  1. Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, 15th Edition, ISBN 978-197-51-6103-3, by Janice L. Hinkle, Kerry H. Cheever, and Kristen J. Overbaugh (Ch. 58, [ebook] pp. 5065–5091)

A cataract is a lens opacity or cloudiness that result in visual disability, being a leading cause of blindness in the world. By 80 years of age, over half of all Americans have cataracts. (Prevent Blindness America, 2020)

Pathophysiology

Cataracts may develop in one or both eyes at any age. The three most common types are traumatic, congenital, or senile cataracts. A variety of risk factors (associated ocular conditions, toxic factors, nutritional factors, physical factors, and systemic diseases or syndromes) exist, but aging is the most common one.

Clinical Manifestations

Painless, blurry vision is characteristic of cataracts. The person perceives that surroundings are dimmer, as if they glasses need cleaning. Light scattering is common, and the person experiences reduced contrast sensitivity, sensitivity to glare, and reduced visual acuity. Other effects include myopic shift (return of near vision), astigmatism (refractive error due to an irregularity in the curvature of the cornea), monocular diplopia, and color changes as lens become more brown in color.

Diagnostic Examination

  • Decreased visual acuity is directly proportionate to cataract density.
  • Snellen Visual Acuity Test, Ophthalmoscopy, and Slit-Lamp Biomicroscopic Examination are used to establish the degree of cataract formation.
  • The degree of opacity does not always correlate with status; some patients perform normal activities despite clinically significant cataracts. Visual acuity is an imperfect measure of visual impairment.

Medical Management

There are no nonsurgical measures that treat cataracts or prevent age-related cataracts. Optimal medical management is prevention. Patients should be educated about risk reduction strategies:

  • Smoking cessation, weight reduction, optimal blood glucose control (diabetics)
  • Wearing sunglasses outdoors to prevent early cataract formation.

Surgical management is not needed if reduced vision from cataracts do not interfere with normal activities. The patient’s functional and visual status are the primary considerations when deciding if cataract surgery should be performed. Restoration of visual function through a safe, minimally invasive procedure is the surgical goal, with advances in topical anesthesia, smaller wound incision, and lens design. Cataract removal is common, and is performed on an outpatient basis, usually taking less than 1 hour and patient discharge within 30 minutes after the procedure. Complications (hemorrhaging, infection, inflammation, malpositioned intraocular lens, opacification of the posterior capsule) are uncommon, but may still occur.

  • Injection-free Topical and Intraocular Anesthesia, such as 1% lidocaine gel is applied to the surface of the eye. IV Sedation may be used to minimize anxiety and discomfort.
  • If cataracts are bilateral, one eye is treated first to preclude whether the other eye should also be treated. The interval is several weeks, preferable months.
  1. Phacoemulsification: an extracapsular cataract surgery where a portion of the anterior capsule is removed, allowing extraction of the lens nucleus and cortex while the posterior capsule and zonular support are left intact.
    • The lens nucleus and cortex are liquefied with an ultrasonic device then suctioned out through a tube.
    • A small incision on the upper edge of the cornea and viscoelastic substance (clear gel) is injected into the space between the cornea and the lens, preventing the space from collapsing facilitating the insertion of the IOL.
    • Results in early stabilization of refractive error, and less astigmatism.
  2. Lens Replacement: after removal of the crystalline lens, the patient is referred to as aphakic (i.e. without lens). The lens that focuses light on the retina needs to be replaced. There are three options:
    • Aphakic Eyeglasses: are rarely used despite their effectivity, as objects become 25% magnified, causing distortion and limited peripheral vision.
    • Contact Lenses: corrects to almost normal vision; when removed as necessary, the patient uses aphakic eyeglasses. These are not advised for patients who have difficulty inserting, removing, and cleaning them. Frequent handling and improper disinfection increases risk of infection.
    • IOL Implants: the most common approach for lens replacement, like in cataract extraction or phacoemulsification. Complications (error, infection) are uncommon. This is contraindicated in patients with recurrent uveitis, proliferative diabetic retinopathy, neovascular glaucoma, or rubeosis iridis.

Nursing Management

  1. Provide Preoperative Care: receive the usual preoperative care for ambulatory surgical patients undergoing eye surgery. The standard battery of tests (CBC, ECG, Urinalysis) are only done when indicated by medical history.
    • Alpha-antagonists (particularly tamsulosin, used for prostate enlargement) are known to cause intraoperative floppy iris syndrome. Miosis and iris prolapse leads to complications. Ask the patient about history of its use, as it may occur even after cessation. Alert the team to this complications.
    • Dilating drops (mydriatics) is given prior to surgery. Patient education is begun about eye medications that will need to be self-administered to prevent postoperative infection and inflammation.
  2. Provide Postoperative Care: before discharge, written and verbal education about eye protection, administration of medications, recognition of complications, activities to avoid, and obtaining emergency care is done.
    • An eye shield is often used for the first week to avoid injury.
    • Mild analgesia (e.g. acetaminophen) may be taken as needed.
    • Antibiotic, anti-inflammatory, and corticosteroid eye drops or ointments are prescribed postoperatively. Anti-inflammatory and corticosteroid use should be monitored for increased IOP.
  3. Self-care: the patient wears a protective eye patch for the first ~24 hours, then eye glasses during the day and an eye shield at night. Educate the patient about applying and care of the eye shield, if recommended. Sunglasses should be worn outside due to light sensitivity.
    • Slight morning discharge, some redness, and a scratchy feeling may be expected for a few days. Clean, damn cloth can be used to remove discharge.
    • Inform the physician if floaters, flashing lights, decrease in vision, pain, or increase in redness occurs. The risk of retinal detachment increases after surgery.

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