Chapter 20 Flashcards
Vision problems
What is a cataract
age-related (senile cataracts) or other (ex. DM, trauma, smoking) opacity in the lens; maybe one or both eyes (vision may be worse in one than the other)
how is a cataract formed
Altered metabolic processes in lens cause h2o accumulation and changes in lens fiber structure -> altered transparency -> vision changes.
What does a cataract look like
A totally opaque lens creates the appearance of a totally white pupil.
Describe how cataracts affect one’s vision.
three
- Graduel decreased vision,
- abnormal color perception,
- and glare (due to light scatter caused by lens opacities) which can be worse at night.
Cite the 2 ways which cataracts can be detected.
Ophthalmoscope: Directly observes opacity
Slit lamp examination: Microscopic examination
what gets implanted when a cataract is removed
Most pts have an Intraocular Lens (IOL)
what drops (2) are used after cataract surgery
Post Op meds include antibiotic drops to prevent infection and corticosteroid drops to decrease inflammatory response. Drops are gradually reduced in frequency and then stopped as eye heals
Describe activities to be avoided after cataract removal. (4)
Bending, stooping, coughing, lifting (activities that increase IOP)
Identify what vision is affected by age related macular degeneration.
Central vision
Review the difference between dry and wet AMD; cite which is more severe. P 369
- Dry (nonexudative): atrophy of macular cells
*More common
*Slow, progressive, painless loss of vision - Wet (exudative):
*More severe; abnormal blood vessels develop in or near macula
*Rapid onset of vision loss; AMD-related blindness
Describe the changes in vision caused by AMD. (4)
Acute vision loss; blurred or darkened vision, scotomas (blind spots) and metamorphopsia (visual distortion)
Cite the location and purpose of injections to help control AMD.
Medications injected every 4–6 weeks into the vitreous cavity to stop new vessel formation and slow vision loss. One of the few tx options for WET AMD
Describe dietary supplements that may help decrease the progression of AMD.
*Vit C, E, beta-carotene, and zinc are the main ones. Lutein/zeaxanthin supplements may help some pts.
*Teach pt to eat dark green, leafy veggies containing lutein (eg. kale, spinach) and fatty fish at least twice a week
Describe glaucoma and its effect on vision. (what and effects)
*What: group of disorders characterized by increased IOP and its consequences and optic nerve atrophy
*Visual effects: peripheral visual field loss leading to permanent blindness.
Describe how glaucoma damages the optic nerve (2)
*Primary open-angle glaucoma (POAG): outflow of aqueous decreased; drainage channels clogged -> optic nerve damage.
*As glaucoma progresses, optic disc cupping may be one of the first signs of POAG. The optic disc becomes wider, deeper, and paler (light grey or white).
