Eye disorders

• Macular degeneration


  central loss of vision that affects macula of the eye, no cure, common cause of vision loss in older adults
• 2 types of macular degeneration

  dry macular and wet macular
• dry macular degeneration


  most common -> gradual blockage in retinal capillary arteries -> macula becomes ischemic and necrotic due to lack of retinal cells
• wet macular degeneration


  less common -> new growth of blood vessels with thin walls that leak blood and fluid
• risk factors for dry macular degeneration


  smoking, HTN, female sex, short body stature, family hx, diet lacking carotene and vitamin E, age > 60, caucasian race
• risk factors for wet macular degeneration


  it can occur at any age
• expected findings of macular degeneration


  lack of depth perception, objects appears distorted, blurry vision, loss of central vision, blindness
• diagnostic procedures for macular degeneration


  ophthalmoscopy --> ophthalmoscope used to examine back part of eyeballs (fundus), retina, optic disc, macula, blood vessels; visual acuity tests --> Snellen test, Rosenbaum eye charts
• Snellen test


  cover one eye and read letters on the chart aloud from top to bottom, measures distance vision

  
• Rosenbaum eye chart


  Used to measure near visual acuity

  
• Care for patients with wet macular degeneration


  laser therapy to seal leaking blood vessels, ocular injections to inhibit blood vessel growth
• patient education for wet macular degeneration:

  • eat foods high in antioxidants, carotene, vitamins E and B12
  • teach that as vision loss progresses, clients may be challenged in ADLs
  • refer patients to community organizations that can assist with transportation, reading devices, large print books
• Cataracts: opacity in the lens of an eye that impairs vision
• causes of cataracts:

  • age related: drying of lens due to water loss -> increases density of lens due to lens fiber compaction
  • trauma: blunt or penetrating injury or foreign body in the eye, exposure to radiation or UV
  • toxic: long term use of corticosteroids, phenothiazine derivatives, beta blockers, mitotic medications
  • associated: DM, hypoparathyroidism, Down syndrome, chronic sunlight exposure
  • complicated: intraocular disease -> retinitis pigmentosa, glaucoma, retinal detachment
• health promotion/disease prevention for cataracts:

  • wear sunglasses while outside
  • wear protected eyewear while playing sports, performing hazardous activities (welding, yardwork)
  • encourage annual eye exams, good eye health in adults over 40
• risk factors for cataract: old age, DM, heredity, smoking, eye trauma, excessive exposure to sun, chronic use of certain medications
• expected findings for cataracts: decreased visual acuity (prescription changes, reduced night vision, decreased color perception), blurry vision, diplopia (double vision)
• diagnostic procedures for cataracts: examination of lens using ophthalmoscope
• nursing care for patients with cataracts:

  • check visual acuity using the Snellen chart
  • examine eye structure with ophthalmoscope
  • determine patient's functional capacity due to decreased vision
  • increase light in a room
  • provide adaptive devices that accommodate for reduced vision
• Medication for cataracts: anticholinergic agents (atropine 1% ophthalmic solution) -> prevents pupil constriction (mydriasis), relaxes muscles in eye (cycloplegia), used to dilate eye for visualization of the eye's internal structures

  • medication has long duration, fast onset
  • client education: effects can last 7-12 days, can cause photosensitivity -> wear sunglasses
• Post-op nursing actions for surgical removal of lens:

  • prevent increase in intraocular pressure
  • prevent infection (manifestations: yellow/green drainage)
  • administer ophthalmic medications
  • provide pain relief
  • teach patient about self-care at home and fall prevention
• Activities that increase IOP (intraocular pressure): bending over at the waist, sneezing, blowing nose, coughing, straining, head hyperflexion, restrictive clothing (tight shirt collars), sexual intercourse
• Complications of surgical lens removal: infections can occur after surgery -> report yellow/green drainage, increased redness/pain, reduction in visual activity, increased tear production, photophobia; bleeding is potential risk for several days after surgery
• Glaucoma: disturbance of the functional/structural integrity of the optic nerve; decreased fluid drainage/increased fluid secretion -> ↑ IOP
• reference range for intraocular pressure

  10-20 mm/Hg
• 2 primary types of glaucoma

  primary open-angle glaucoma

  primary angle closure glaucoma
• primary open angle glaucoma


  more common, angle between iris and sclera is open, aqueous humor outflow is decreased due to blockage in eye's drainage system -> gradual ↑ of IOP
• primary angle closure glaucoma


  IOP suddenly rises, angle between iris and sclera suddenly closes -> ↑ IOP, sudden onset, requires immediate treatment
• secondary glaucoma


  from trauma, eye surgery, tumors of the eye, uveitis, iritis, neovascular disorders, degenerative disease, central retinal vein occulsion
• risk factors of glaucoma


  age, infection, tumors, DM, genetics, HTN, eye trauma, severe myopia, retinal detachment
• expected findings: primary open angle glaucoma


  headache, mild eye pain, loss of peripheral vision, ↓ accommodation, halos seen around lights, ↑ IOP (>20 mmHg)
• expected findings: primary angle closure glaucoma


  rapid onset of IOP (30 mmHg or higher), ↓ or blurred vision, colored halos seen around lights, pupils nonreactive to light, severe pain/nausea, photophobia
• diagnostic procedures for glaucoma


  visual assessments (to measure ↓ in visual acuity and peripheral vision), tonometry (measure IOP), gonioscopy (determines drainage angle of anterior chamber of the eyes)
• basic patient education for medication for glaucoma: wait 5-10 minutes between eye drops if more than 1 is prescribed to prevent one medication from diluting the other, avoid touching the tip of application bottle to eye, always wash hands before and after use, apply pressure using punctual occlusion technique (place pressure on inner corner of eye) after eye drop has been instilled
• Cholinergic agents for glaucoma:

  • carbachol, echothiopate, pilocarpine
  • all miotic medications -> constrict pupil to allow for improved circulation and outflow of aqueous humor
  • can cause blurred vision
  • educate patient to use good lighting to avoid falls
• Adrenergic agonists for glaucoma:

  • apraclonidine, brimonidine, tartrate, dipivefrin hydrochloride
  • reduce intraocular pressure by limiting production of aqueous humor, dilates pupil to improve fluid flow to site of absorption
  • educate client to wear sunglasses in bright light
• Beta blockers for glaucoma:

  • timolol
  • first line drug therapy for glaucoma
  • ↓ IOP by reducing aqueous humor production
  • can be absorbed systemically -> bronchoconstriction, hypoglycemia
  • use with caution in clients with asthma, COPD, DM
  • can potentiate systemic effects of oral beta blockers -> bradycardia, hypotension
• Carbonic anhydrase inhibitors for glaucoma:

  • acetazolamide, dorzolamide, brinzolamide
  • ↓ IOP by reducing aqueous humor production
  • check allergies to sulfa as medication is sulfa based
• Prostaglandin analogs for glaucoma:

  • bimatoprost, latanoprost
  • ↑ outflow of uveosclera by dilating blood vessels in trabecular mesh where aqueous humor is collected, then drains the humor at a more rapid rate
  • education: check for corneal abrasions and do not instill if cornea is not intact, can cause iris to change color by darkening with long term use
• systemic osmotics for glaucoma:

  • IV mannitol: osmotic diuretic used in emergency treatment for primary angle closure glaucoma to quickly decrease IOP
  • oral glycerin