7. Vision

Question 1

Age related changes to vision

Answer 1

• corneal yellowing and increased opacity
• changes in corneal curve
• increased lens flexibility and density, opaque
• decrease pupil size
• sclerosis and rigidity of iris
• atrophy of ciliary muscle
• shrinkage of gelatinous substance in the vitreous
• atrophy of photoreceptor cells
• thinning and sclerosis of retinal blood vessels
• degeneration of neurons in the visual cortex

Question 2

Functional consequences of impaired vision

Answer 2

• need for 3-5 times more light than before
• effect on driving
• increased risk for unsafe mobility and falls
• increased difficulty performing ADLs
• anxiety, depression, lower levels of psychological well-being

Question 3

copy paste of age related changes

Answer 3

Cornea- yellowing and increased opacity, changes in curvature
Arcus senilis- grey around iris
lens- increase in size and density
Iris- sclerosis and rigidity of the iris
Pupil- decrease in size = less light entering retina
Ciliary muscle- stiffening, atrophy of muscle
Vitreous body – shrinkage of gelatinous substance in the vitreous
Photoreceptor cells- (usually converts light into electrical signals to nerve cells) - atrophy (die)
retinal blood vessel – thinning and sclerosis of vessel
optic nerve- slower processing of visual information
Visual cortex- degeneration of neurons in visual cortex p. 330

Question 4

Consequences of Age-Related Changes on Vision

Answer 4

• diminished acuity
• slower response to changes in light
• increased sensitivity to glare
• narrowing visual field
• lower depth perception
• altered colour perception
• distorted perception of flashing lights
• diminished processing of visual information
• dry eyes

Question 5

4 Pathologic conditions affecting vision

Answer 5

1. cataract
   - leading, reversible cause of vision impairment
2. age-related macular degeneration
   - leading cause of severe vision loss
3. glaucoma
   - causes loss of peripheral vision leading to blindness if untreated
4. diabetic retinopathy

Question 6

Cataract

Answer 6

• Lens becomes cloudy= light scatters= blurry vision
• Leading cause of avoidable blindness
• Caused by age-related changes or congenital - due to an illness, likerubella, that your mother had duringpregnancy.
• Risk factors include: exposure to sunlight, smoking, malnutrition, trauma, adverse med reactions, diabetes

Assessment:
Symptoms include 
C: cloudy blurry
A: Acquiring more light
T: toned down colour
H: Halos around objects
Y: yellow tint to most things

Interventions:

• surgical removal of lens and installation of artificial lens
• teaching about benefits of surgery for people with information processing difficulties (dementia, depression)
• smoking cessation
• use sunglasses

Question 7

Age-related Macular Degeneration (AMD)

2 types: wet, dry

Answer 7

2 types of central vision loss, peripheral vision stays intact

1. wet - more severe, ends in blindness
2. dry - less severe, progresses slowly

-no cure
-treatment is limited because of the slow progression
-focus on screening, early detection, prevention
Assessment:
-test eyes daily with Amsler grid to catch sudden changes to central visual field
-face test- cover one eye and look in mirror to notice any central blurring or missing parts

Interventions:

• no cure
• no treatment
• focus on health promotion:
• diet high in antioxidants like dark green veg
• eat fish for omega 3
• improve cardio health
• smoking cessation
• reduce HTN
• control weight
• avoid processed foods

Question 8

Glaucoma

3 types

Answer 8

Eye disease with elevated intraocular pressure in which damage to the eye optic nevre can lead to loss of vision and blindness

1. Chronic (open-angle)
   - most common
   - IOP
   - cause: clogged trabecule
   - early signs: poor vision in dim light, increased sensitivity to glare
   - progression: headaches, tired eyes, poor peripheral vision, halos around lights
   - annual eye exams to detect
   - treated with meds or laser
   - painless
2. Normal Pressure
   - optic nerve is damaged yet NO IOP
   - unknown cause
   - blind spots due to damaged nerve fibers
   - permanent blindness unless treated with drops or surgery
3. Acute (closed-angle)
   - fluid cannot go anywhere so goes back to eyes and builds up and pushes on retina
   - IOP increases quickly as drainage is blocked
   - less common
   - MEDICAL EMERGENCY
   - symptoms: pain, blurred vision, headache, pupil dilation, high IOP, nausea, vomiting
   - blindness unless treated with meds or surgery

Assessment:

• past medical hx
• age 65+ annual eye exam for screening
• pts with medication controlled glaucoma should have check-up q6months
• annual screening for Asian, African, Hispanic, and family hx of glaucoma who are age 40+

Interventions:

• medications to decrease IOP
• laser surgery
• use of colour contrast to identify objects, glare control
• semi or annual eye exams

Question 9

Diabetic Retinopathy

Answer 9

• effects of elevated blood sugar caused by diabetes
• disease of microvasculature
• increased vessel permeability= blood and lipid leakage leads to macular edema and hard exudates
• Hard exudates(lipid)Hard exudatesare small white or yellowish-white deposits with sharp margins. Often, they appear waxy, shiny, or glistening. They are located in the outer layers of the retina, deep to the retinal vessels.

Assessment:

• early signs are microaneurysms, flame-shaped hemorrhages, hard exudates
• annual dilated funduscopic exam of the eye beginning 5 years after diagnosis of type 1 diabetes and at the time of type 2 diagnosis

Interventions:

• constant control of blood glucose, cholesterol, and BP
• laser photocoagulation treatments to halt disease progression (Photocoagulation = a laser is used to finely cauterize ocular blood vessels to attempt to bring about various therapeutic benefits.)

General Interventions:

• sunglasses
• regualr eye exams
• proper lighting
• good nutrition
• smoking cessation
• med compliance