Low Vision Disorders

Question 1

Low vision disorders

Answer 1

• 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

Question 2

Low vision

Answer 2

• 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

Question 3

Age-related changes in vision

Answer 3

• 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

Question 4

Age-related macular degeneration (AMD)

Answer 4

• 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

Question 5

Dry AMD

Answer 5

• 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

Question 6

Wet AMD

Answer 6

• 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

Question 7

Classifications of AMD

Answer 7

• 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

Question 8

Signs and symptoms of AMD

Answer 8

• 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

Question 9

Prevalence of AMD

Answer 9

• 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

Question 10

Risk factors for AMD

Answer 10

• 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

Question 11

Medical/surgical management of AMD

Answer 11

• 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)

Question 12

Functional vision with AMD

Answer 12

• difficulty seeing faces
• difficulty reading
• difficulty following straight lines
• increased sensitivity to light
• spilling liquids when pouring

Question 13

Glaucoma

Answer 13

• 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

Question 14

Signs and symptoms of glaucoma

Answer 14

• 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

Question 15

Prevalence of glaucoma

Answer 15

• 2010 = 2.7 million people with glaucoma
• 2050 = 6.3 million people will have glaucoma

Question 16

Cataracts

Answer 16

• opacifications of the lens of the eye, which result from a buildup of opaque, broken proteins (crystalline) that stick together and form sheathlike obstructions that decrease the amount of light reaching the retina
• clouding of the lens of the eye (and darker)
• can occur in one or both eyes
• most often affects adults over age 60
• by age 80, more than 50% of all Americans will have had a cataract
• should be treated when it begins to interfere with ADL/IADL
• the light rays are diffused by a cataract

Question 17

Signs and symptoms of cataracts

Answer 17

• decreased visual acuity
• cloudy, blurry, or foggy vision
• decreased contrast sensitivity
• increased glare sensitivity
• near-sightedness (myopia)
• decreased color perception especially towards the blue hues
• perception of halos around the lights
• glare from the sun seem bright
• poor night vision
• double images
• consistent change of prescription of contact lens
• color seems faded

Question 18

Prevalence of cataracts

Answer 18

• 2010 = 24.4 million people have cataracts
• 2050 = 50 million people will have cataracts

Question 19

Risk factors of cataracts

Answer 19

• aging = strongest risk factor
• familial history of cataracts
• cigarette smoking
• ocular ultraviolet-B and radiation exposure
• drug use
• systemic diseases (ex: diabetes)
• eye trauma
• dietary nutritional intake
• drugs associated with increased cataract risk = corticosteroids, antipsychotics, chemotherapy agents, cholesterol-lowering medications, and tranquilizers
• heavy alcohol consumption (ETOH)

Question 20

Medical/surgical management of cataracts

Answer 20

• initially managed by prescription lenses, tobacco cessation and UV protection
• surgical removal of the lens either by laser or scalpel (cataract surgery)
• surgery is conducted when the client is advanced to a stage that interferes with a person’s ability to function
• done one eye at a time to assure adequate treatment of any complications and to avoid bilateral vision loss

Question 21

Functional vision with cataracts

Answer 21

• difficulty reading
• trouble with glare from headlights during night driving
• needing to change glasses more frequently
• colors may seem more dull

Question 22

Diabetic retinopathy

Answer 22

• complications of diabetes = too much sugar in your blood can damage your retina (the part of your eye that detects the light and sends signals to your brain through a nerve in the back of your eye; optic nerve)
• one of the leading causes of blindness (retinal detachment = automatically becomes blind)
• may not be symptomatic initially, vision fluctuates
• encourage all clients with diabetes to get an annual comprehensive eye exam
• all people with diabetes are at risk
• 40-45% of Americans with diabetes have diabetic retinopathy
• treatment primarily aimed at slowing progression
• too much blood sugar in your arteries in your eye kind of causes baby aneurysms, which can cause baby mini strokes
• becomes permanent

Question 23

Symptoms of diabetic retinopathy

Answer 23

• eye pain
• loss of central vision
• dark spots and floaters
• blind spots
• blurred vision
• fluctuating vision
• poor night vision

Question 24

Prevalence of diabetic retinopathy

Answer 24

• 2010 = 7.7 million people have diabetic retinopathy
• 2050 = 14.6 million people will have diabetic retinopathy

Question 25

Functional vision with diabetic retinopathy

Answer 25

- vision fluctuates with blood sugar levels - trouble seeing faces - trouble reading - difficulty reading - difficulty seeing colors - may eventually lose vision