class 6 the eye Flashcards
glaucoma, cataracts, macular degeneration
what is cataracts
-opacity of the lens of the eye, diminished vision
-decrease in amount of light that reaches
-impairment depends location & density of opacity
what is cortical cataracts
-slower progression, less severe diminishing of vision
what is nuclear cataracts
progressive, yellowing & hardening of the eye
-usually ages 70+ (dehydration)
what is posterior subcapsular cataracts
central vision loss->progresses to blindness
pathophysiology of cataracts
-aging causes loss H2O & inc density lens
-compaction of lens fibers reduces H2O content lens
-proteins precipitate & form crystals
-lens less transparent over time
etiology of cataracts: age
age: 65+ inc risk
etiology of cataracts: comorbities
-comorbities: diabetes, lipid/renal/musculoskeletal disorder inc risk
etiology of cataracts: physical factors
-physical:UV light, dehydration trauma
etiology of cataracts: occular conditions
retinitis, retinal surgery, eye infection prone
etiology of cataracts: toxic factors
smoking, long term steroid use, copper, silver, mercury
etiology of cataracts: congenital factors
prev/in utero polio, measles, hepatitis
signs and symptoms of cataracts
seeing halo around lights
-decreased visual activity
-increased sensitivity glare
-double or hazy vision
-decreased colour vision
-abscent red reflex
-NO PAIN****
Surgical treatments for cataracts
topical and/or regional anesthesia and/or IV sedation
replacement of lens with artificial lens
-only surgical interventions can get rid of cataracts
post-op care/teaching for cataracts surgery
-report sudden sharp pain, bleeding, discharge, edema, decreased vision s/s of retinal detachment
-eye drop teaching (abx, steroids->may be painful)
-avoid IOP & prevent injury (not straining, bending, lifting)
-eye patch post op
-no blood thinners
characteristics of glaucoma
-abnormal pressure within eyeball
-leading to optic nerve atrophy
-eventual blindness
-imbalance between production & drainage of aqueous fluid; anterior chamber congested & IOP rises
-individual is unaware until there is significant vision loss “silent thief”
pathophysio of glaucoma
aqueous production & drainage are not in balance
-aqueous overflow block=inc IOP
-inc IOP causes irreversible emchanical pr ischemic damage
glaucoma risk factors
family hx
-40+
-diabetes (x2 chances esp for open-angle)
-cardiovascular disease
-migraine hx
-myopia
-eye trauma
-ethicity
-prolonged use of corticosteroids
what is open-angle glaucoma (POAG)
-most common
-usually bilateral & asymptomatic early stages
-structures in drainage system degenerate & exit channels for aqueous fluid blocked
-22-32 degree angle
s&s of open angle glaucoma
-inc IOP
-bilateral, gradual, painless onset
-mild aching
-headache
-coloured halos around lights
-reduced peripheral vision & acuity
-opthalmoscopic exam
-optic nerve pale & indented, cloudy aqueous humour, dilated nonreactive pupil
angle-closure glaucoma (pupillary block)
-occurs among people with anatomically narrowed angle at junction where iris meets cornea
-when iris protrudes into anterior chamber, aqueous fluid blocked
-occurs suddenly (emergency)
-blindness if not tx
>50 degree angle
s&s of angle-closure glaucoma
-occur suddenly
-sudden excruciating pain around eyes
-headache/brow ache
-n&v
-coloured halos around lights
-blurred vision
-occular reddness
-may cause frosted cornea
diagnostic tests for glaucoma
-tonometry to assess IOP
-gonioscopy to assess the angle of the anterior chamber
-perimetry to assess vision loss
medical management for glaucoma
-early detection & lifelong tx prevent blindless
-medications
medications used for tx glaucoma
-miotics (cholinergics) constrict pupil (pilocarpine gtts)
-alpha & beta blockers reduce aqueous humor (propine, timolol gtts)
-osmotic agents (emergency) reduce IOP (IV mannitol)
surgical management for glaucoma
-laser trabeculoplasty (inc drainage)
-laser iridectomy
-filtering procedures
-drainage implants
nursing care for glaucoma
-do not lie on operative side
-assess IOP and pain
-assist ADL if needed
-stress compliance to meds
-teach gtt administration
-encourage family to be assessed
what is macular degeneration
-common in smokers
-deterioration of the macula, area of central vision
- non- exudative vs exudative
what is non-exudative macular degeneration
-age related/dry
-characterized by sclerosing of retinal capillaries=ischemia/necrosis of macular cells
what is exudative macular degeneration
-presence of drainage (wet)
-rod and cone photoreceptors die - dec central vision
-exudative degeneration = sudden dec in vision
tx and nursing management for macular degeneration
-maximize remaining vision/slow the process
-laser therapy limits damage
-education
