Low Vision Disorders Flashcards
1
Q
Low vision disorders
A
- progressive diseases that lead to chronic loss of eyesight or blindness
- limits the person’s independence (changes the way the person does things)
- increases the risk for depression, social isolation, general decline in health
- leads to increased risk of falls, poor medicine management (so many medications look alike) and reduced activity levels
- globally estimated 36 million people are blind and 216.6 million people have moderate to severe visual impairments
*unless you are a specialist, it is not our primary diagnosis we are treating but we have to keep it in the back of our heads because it impacts what we are treating
2
Q
Low vision
A
- a vision that cannot be corrected normally by glasses, contact lenses, medications, or surgeries
- legal blindness in the U.S. = a person has corrected vision of 20/200 or worse in the better eye OR when a person’s visual field is 20 degrees or less (can only see things straight ahead)
- total blindness in Missouri = 5/200 or worse in the better eye OR a visual field of 5 degrees or less
3
Q
Age-related changes in vision
A
- presbyopia = difficulty focusing on near (reading) and intermediate (computer) objects that begins in your 40s
- increased dryness in the eyes begins in your 40s causing irritation and increased risk for infection
- increased need for light for completing near tasks
- increased time needed to adjust when going from a lighter to a darker environment
4
Q
Age-related macular degeneration (AMD)
A
- one of the leading causes of vision loss in older adults
- affects the retina and central vision (will NOT cause blindness)
- two forms = exudative (wet) and non-exudative (dry) = destroying the central vision
- treatments aimed at slowing progression = trying to keep vision as much as possible since there is no reversal
- affects adults at age 50 and older
- Caucasians are at a higher risk of developing AMD
- people with a family history of AMD are also at higher risk
5
Q
Dry AMD
A
- crumbly
- breaking down of the inner layers of the macula
- the part of the retina that gives the eye clear vision in the direct line of sight
- more common and progresses slowly
- usually fuzzy or distorted vision
6
Q
Wet AMD
A
- arteries leaking into your eye
- abnormal blood vessels form in the eye that leak proteins and lipids
- causes relatively sudden change in vision and results in more serious vision loss
- blind spot in center of field of vision
7
Q
Classifications of AMD
A
- early AMD = the retina is showing beginning signs that it is unhealthy and predisposed to developing the disease (start on meds to try to slow it down)
- intermediate AMD = disease is evident and beginning to impact vision in one or both eyes
- advanced AMD = significant loss of central vision, which can occur rapidly or gradually and progressively
8
Q
Signs and symptoms of AMD
A
- acute loss of central vision
- loss of visual acuity
- metamorphosia = distortion of objects
- central scotomas
- increased glare sensitivities
- decreased contrast sensitivity
- decreased color vision
- experiencing blurry vision when looking at the center of something
- difficulty reading and other fine tasks like threading a needle in low-light settings
- seeing straight lines as blurry
- noticing blank spots in central vision field
9
Q
Prevalence of AMD
A
- leading cause of severe vision loss for people older than 50
- 3rd leading cause of vision loss globally
- 2010 = 2.1 million people with AMD
- 2050 = 5.4 million people will have AMD
10
Q
Risk factors for AMD
A
- combination of aging, genetic, and environmental factors
- family history of AMD, light eye color, far sightedness and Caucasian skin
- smoking, obesity, HTN, dietary deficiencies in Vitamin A, D, E, zinc lutein, and omega-3 fatty acids, and ultraviolet light exposure
- cigarette smoking = number one environmental risk factor
11
Q
Medical/surgical management of AMD
A
- nutritional supplements = Vitamin C, E, zinc oxide, cupric oxide, lutein, and zeaxanthin (depends on the genotypes)
- medications for wet AMD = ranibizumab, bevacizumab, and afibercept (slow progress)
- photodynamic therapy and laser treatments are used for treating wet AMD
- injection of the drug Visudyne (binds to abnormal vessels to prevent regrowth; in wet AMD, abnormal blood vessels grow under the central part of the retina called the macula; if these vessels burst, the resulting pressure can damage sensitive tissues and warp vision)
12
Q
Functional vision with AMD
A
- difficulty seeing faces
- difficulty reading
- difficulty following straight lines
- increased sensitivity to light
- spilling liquids when pouring
13
Q
Glaucoma
A
- a group of diseases affecting the optic nerve
- angle-closure glaucoma = drainage canals are clogged, fluid pressure builds up
- open-angle glaucoma = angle between the iris and cornea is too narrow and futile pressure builds up
- neovascular glaucoma = eye pressure buildup and damage to optic nerve
- caused by an increased intraocular pressure (IOP)
- causes peripheral vision loss initially; may cause blindness (tunnel vision)
- “sneak thief of sight”
- treatments aimed at slowing progression
- occurs primarily in adults over age 60
- African Americans over age 40 are at higher risk
- Mexican Americans over age 60 are at higher risk
- people with family history are at higher risk
14
Q
Signs and symptoms of glaucoma
A
- slow loss of peripheral vision
- decreased ability to see in dim light
- decreased contrast sensitivity
- poor adaptation to changes in light
- increased glare sensitivity
- burred vision
- decreased depth perception
- ocular pain
- eventual loss of central vision
- high intraocular pressure
- lacrimation = tears
- redness of the eye
- fatigue of organs of vision
- the appearance of bright rainbow rim around any light source and other objects
- head pain
15
Q
Prevalence of glaucoma
A
- 2010 = 2.7 million people with glaucoma
- 2050 = 6.3 million people will have glaucoma
