Low Vision Final Study Guide Part 3

Question 1

Be able to distinguish comparison of control differences between the endocrine and nervous systems.

Answer 1

* Nervous and endocrine systems act together to coordinate functions of all body systems.
– Nerve impulses trigger release of neurotransmitters.
– Endocrine system releases mediators called hormones.
1. endocrine system – Slow responses: growth, metabolism
* Hormones transmitted throughout body
* Act far from site of release (bloodstream)
* Target cells throughout body
* Onset is slow (seconds to hours to days)
* Duration is long (seconds to days)
2. nervous system – Rapid responses: skeletal muscle contraction
* Neurotransmitters released locally
* Act close to site of release (at synapse)

Question 2

Understand how hormones released from an endocrine gland reach and influence target cells.

Answer 2

• Hormones are molecules released in one part of the body but regulate activity elsewhere.
  – Delivered to cells through the bloodstream
• Hormones (like neurotransmitters) influence target cells by binding to specific receptors.
• Only target cells for a given hormone have receptors that will recognize and bind it.

Question 3

Understand what a cell target cell may do in the presence of excess hormone quantity and in deficient hormone quantity. What effect does this have in terms of sensitivity to a hormone?

Answer 3

• If a hormone is present in excess, the number of target receptors may decrease.
  – Process is called down regulation
  – Makes cells less sensitive to hormone
• When a hormone is deficient, the number of target receptors may increase.
  – Known as up regulation
  – Makes cells more sensitive to hormone

Question 4

Be able to distinguish between the hormones secreted by alpha pancreatic islet cells and beta pancreatic islet cells.

Answer 4

* Alpha cells secrete glucagon
– Glucagon raises blood glucose levels when low (signals liver to release glucose).
* Beta cells secrete insulin
– Insulin lowers blood glucose levels when high (signals cells to take up glucose).

Question 5

Know the steps involved in regulation of glucagon and insulin!

Answer 5

1. Low blood glucose levels (hypoglycemia) stimulate secretion of glucagon form alpha cells.
2. Glucagon acts on liver cells to release glucose.
3. Blood glucose levels rise.
4. If blood glucose continues to rise, high blood glucose level (hyperglycemia) inhibits release of
   glucagon.
5. Hyperglycemia stimulates secretion of insulin by beta cells.
6. Insulin acts on cells to accelerate diffusion of glucose into cells (among other things).
7. Blood glucose level falls.
8. If blood glucose level drops below normal, hypoglycemia inhibits release of insulin and stimulates
   release of glucagon.

Question 6

Be able to distinguish between Type 1 and Type 2 diabetes mellitus.

Answer 6

Type 1
* Result of an absolute deficiency of insulin secretion.
* Autoimmune process destroys pancreatic beta cells.
* Insulin is not produced or released into bloodstream.
* Accounts of 5% - 10% of cases
* Previously referred to as juvenile diabetes or insulin-dependent diabetes

Type 2
* Results when body is resistant to effect of insulin, or Beta cells produce insulin, but in insufficient amounts
* Glucose stays in the bloodstream and is unavailable for energy.
* Body must burn protein and fat
* Accounts for 90% - 95% of cases

Question 7

What is the most important risk factor for Type 2 diabetes?

Answer 7

Obesity

Question 8

Recognize possible complications (comorbidities) associated with diabetes?

Answer 8

• Cardiovascular disease, stroke, blindness, neuropathy
• Associated with ten year shorter life expectancy
  – Heart disease
  – Dental disease
  – Stroke
  – Hypertension
  – Kidney failure
  – Nervous system disease
  – Vision related problems, i.e., diabetic retinopathy

Question 9

Which type of diabetic retinopathy is the most serious form?

Answer 9

Proliferative

Question 9

How are blood glucose levels associated with diabetic retinopathy?

Answer 9

• Major cause of vision loss is damage done by persistent high blood glucose to the small blood vessels of the retina.
  – Retinal blood vessels leak or become blocked, impairing vision over time
  – If abnormal new blood vessels grow on surface of retina, can cause serious damage

Question 10

Is visual fluctuation associated with diabetes? In what way?

Answer 10

Yes – changes with rising and falling blood glucose levels

Question 11

What is a CDCES (previously known as CDE)?

Answer 11

• Certified Diabetes Educator
  – Most CDEs are nurses, registered dieticians, physicians, pharmacists, and some OTs

Question 12

What effect does physical activity have on blood glucose levels? Should a person with diabetes monitor BG levels prior to exercising?

Answer 12

yes
* For the person with diabetes, activity level is even more important to maintain blood glucose control
* Helps improve body mass index, enhances weight loss, help control lipids and blood pressure and reduces stress
* Physical activity program may need to be adapted in the presence of complications
* Exercise Induced Hypoglycemia
– Hypoglycemia is the most commonly encountered problem for those taking oral medications or insulin

Question 13

What are some physical activity precautions for a person with diabetes?

Answer 13

1. Have a simple carbohydrate available during exercise program
2. Encourage carrying diabetes identification
3. Wear appropriate shoes
4. Avoid exercises that can aggravate diabetic retinopathy and other conditions:
   – Lowering head below waist level
   – Vigorous bouncing
   – Holding breath while sustaining effort
   – Strenuous upper extremity exercise

Question 14

What are some of the basics of healthy eating?

Answer 14

• Healthy food choices
  – Decrease saturated fat intake (<7% of total calories)
  – Minimize intake of trans fats (to lower LDL and increase HDL cholesterol)
  – Monitor carbohydrate intake
  – Eat whole grains, fresh vegetables, and fruits
• Understanding portion control
• Learning the best times to eat

Question 15

Be able to determine if someone’s meal is within a given recommended carbohydrate range by reading nutrition labels.

Answer 15

Goal is 45 to 55 grams per meal
– 1 carb serving is approx. 15 grams, so 3 servings of carbs per meal would be 45 grams
– E.g., slice of cake = 45 grams or 3 servings of carbs
Must reference “serving size”
– # of carbs per serving

Question 16

How does Metformin work as an oral diabetes medication?

Answer 16

Metformini s generally the first medication prescribed for type 2 diabetes. It works primarily by lowering glucose production in the liver and improving body’s sensitivity to insulin so that it uses insulin more effectively.

Question 17

Why might drawing insulin be a challenge for persons with low vision?

Answer 17

Seeing the colorless insulin level and the small numbers on the side of the syringe.
–** Requires good acuity**
– Requires good contrast sensitivity

Question 18

Be able to distinguish between the 3 types of insulin delivery systems.

Answer 18

1. Syringes
   – Cheapest
   – Ability to mix
   – Come in different unit measurements to match dose 2.
2. Pens
   – Prefilled insulin cartridges of single or mixed insulin types
   – Reusable or disposable
   – Measure dosage by turning dial (audible and tactual click per unit of measurement)
   – Discrete
   – May be more costly
3. Pumps
   – Connects to flexible tubing
   – Needle inserts into abdomen
   – Delivers steady basal dose
   – Person adjusts bolus doses at mealtimes

Question 19

How is diabetes associated with skin integrity?

Answer 19

Neuropathy – over time diabetes affects circulation and nerve endings
* Decreased circulation affects body’s ability to heal
– Minor injuries like blisters and scrapes don’t heal
– Increases risk for infection
* Decreased sensation means
– Person may not “feel pain” or recognize signs of infection

Question 20

Be able to describe appropriate skin care/foot care precautions.

Answer 20

Skin Care Precautions
* Wearing hard soled shoes
– Unobstructed pathway
* Checking water temperature before bathing
* Avoiding use of hot and cold packs

Foot Care
1. Wash and dry feet thoroughly each day
2. Inspect feet daily by running fingers over entire surface of foot
– Have a sighted person visually inspect and confirm * Check any irregularity
– Small problems become big complications
3. Apply lotion daily, but not between toes
4. Do not cut own toenails
– Ask sighted person
– Podiatrist
5. Check shoes inside before putting them on to remove small stones etc.
6. Pay attention to unusual smells when taking off shoes
– Can be a sign of infection

Question 21

What is an appropriate blood glucose reading for a person with diabetes 2-hours after a meal?

Answer 21

less than < 180 mg/dl

Question 22

Distinguish between hypoglycemia and hyperglycemia. When is each a serious condition?

Answer 22

Hypoglycemia (BG < 70 mg/dl)
– Very dangerous condition
– Without intervention, can lead to coma or death
Hyperglycemia (BG above 150)
– Everyone experiences hyperglycemia after meals (normal)
– Not a medical emergency if transitory
– If levels stay high over extended period of time, can lead to complications

Question 23

Distinguish between symptoms of hypoglycemia and hyperglycemia.

Answer 23

• Hypoglycemic symptoms include:
  – Shaking
  – Sweating
  – Irritability
  – Confusion
  – Tingling
• Hyperglycemic symptoms include:
  – Increased thirst
  – Dry mouth
  – Frequent urination
  – Headache
  – Blurred vision
  – Sleepiness/Lethargic

Question 24

What should you do if you need to intervene for a person experiencing hypoglycemia?

Answer 24

1. Complete a blood glucose test, if possible
2. If not possible, treat anyway – safer than waiting
3. Person must quickly ingest 15 grams of simple carbohydrate:
   – 1⁄2 banana
   – 1⁄2 can regular soda (not diet)
   – 4 ounces of juice
   – 5-6 hard candies
   – 1 cup of milk
4. Glucose enters bloodstream in about 15-20 minutes
5. Test blood glucose again
   – If below 70 mg/dl eat another 15 grams of carbs
6. If level is okay but next meal is over 1 hour away, eat another snack with starch and protein
   – E.g., peanut butter or cheese crackers, 1⁄2 ham or turkey sandwich, cereal with milk

Question 25

Be able to recognize appropriate preventative services for reducing diabetes complications.

Answer 25

Educating and referral for preventative services
– Dilated eye examinations
– Tests of kidney health
– Test of cholesterol level (cardiovascular health)
– Smoking cessation
– Dental examinations
– Flu shots

Question 26

Be able to select an appropriate coping intervention for diabetes.

Answer 26

1. Integrate effective emotional support into the intervention plan to facilitate adjustment
2. Refer client to psychological intervention when appropriate
3. Encourage person to talk about concerns, fears, identify factors that can be controlled and those that cannot
4. Set realistic goals based on the persons motivation
5. Provide updated, accurate education regarding myths and facts about diabetes management, in turn reducing the persons fears and anxiety
6. Implement stress management and relaxation techniques

Question 27

Describe the concept of Life Space and its association with depression.

Answer 27

• Life space- An area which people move in daily life
• Statistically relationships between life space and depressive symptoms in community dwelling adults.
• Restriction in mobility can lead to depression.

Question 28

Distinguish between the concepts of orientation and mobility.

Answer 28

Orientation – the process of using the senses to establish one’s position and relationship to other significant objects in the environment
Mobility – ability to navigate safely from one’s present position to one’s desired position in another part of the environment

Question 29

Describe how some strokes can impact orientation.

Answer 29

Spatial navigation, i.e., cognitive maps, can be significantly impaired following some strokes:
– Those affecting temporal and parietal lobes
– Lose “mental maps”

Question 30

Describe the relationship between visual acuity, contrast sensitivity, and visual field with mobility.

Answer 30

1. Visual Acuity
   – Little correlation between acuity level and ability to safely traverse environment
   – Does make a difference in speed of information processing (necessitates intact visual
   field), so can affect safety performance in dynamic environments.
   – Distance acuity is most important for mobility
2. Contrast Sensitivity
   – Important for feature detection
   – Awareness of changes in support surface
   – Awareness of obstacles
3. Visual Field
   – Extremely important for mobility
   – Must have awareness of objects in environment
   – Particularly impaired with peripheral field loss

Question 31

Distinguish between central field and peripheral field loss and their effect on mobility.

Answer 31

Central Visual Field Loss
* Effect on mobility:
– Collisions
– Trips and stumbles
– Falls
– Increased disorientation
– Increased anxiety
– Unable to anticipate surface changes
Peripheral Visual Field Loss
* Effect on mobility:
– Orientation
– Seeing directional signage
– Identifying landmarks
– Detecting low contrast surfaces
– Depth perception problems

Question 32

Describe how visual information gathered from the environment is used for functional mobility.

Answer 32

1. Gather information about obstacles and threats in the environment
2. Gather information about the nature of objects to be manipulated and acted upon
3. The visual information acquired is used to plan movement and postural accommodations

Question 33

Distinguish between who is responsible addressing functional mobility in the healthcare and blindness systems.

Answer 33

• OT and PT both have responsibility for addressing functional mobility within the healthcare system.
• Orientation and mobility (O&M) specialists fill this role in the blindness system.

Question 34

Understand when O&M services should be initiated.

Answer 34

• Begin as early as possible to effect long term outcomes
  – Learning capacity is at greatest between 0 to 6 years
  – Birth to 3 years intervention improves learning for ages 3 to 5

Question 35

Distinguish between the role of the O&M and OT in functional mobility. What is within the scope of OT?

Answer 35

1. Orientation and Mobility Specialists
   * Usually works one-on-one with students/clients following a customized plan of instruction
2. Independence and safety as goals –
   * Long cane travel: not within the scope of OT
   * Outdoor mobility: **not **within the scope of OT
   * Indoor mobility:

Question 36

Recognize appropriate mobility intervention strategies for the OT generalist. Be able to select an appropriate strategy given a short scenario.

Answer 36

Modify environments
–* Environments should be modified to facilitate independence and safety*
* Ensure lighting is adequate
* Remove obstacles and potential hazards
* Increase contrast of key structures
* Decrease glare * Reorganize
Increase proficiency of visual skills
– Use of existing PRL for scanning environment and locating distance objects
– Apply knowledge of where objects are typically located to direct scanning and increase
speed
* Apply cognitive strategies
– Planning ahead for challenges, i.e., dark restaurants, transitioning between dark and light
areas, handling crowds
– Apply blur interpretation
– Establish landmarks
* Apply simple techniques for indoor mobility
* Teach human guide
* Techniques to manage glare
* Techniques to increase distance acuity and ability to see detail

Question 37

Describe appropriate methods for handling glare.

Answer 37

Indoor Glare
– Lightly tinted UV filters to block glare without significantly reducing light transmission
– Regular sunglasses too dark
– Manage lighting when able
Outdoor Glare
– Darkly tinted UV filters to reduce glare and light transmission during day
– Light yellow UV filters good for night driving to reduce glare from headlights
Transitioning Between Settings
– Put on filters before going out and leave on when coming in

Question 38

Recognize the proper techniques for trailing, alignment, and squaring off.

Answer 38

Trailing
– Use if there is a continuous surface between destinations
– Flex shoulder at about 45 degrees, arm in front of body.
– Use back of hand with curled fingers and wrist slightly flexed
Alignment
– Use when there are gaps in the trailing surface
– Use the edge of a piece of furniture to aim oneself toward a destination
– Person aligns self parallel with surface to establish a line of travel, then continues across
the open area and resumes trailing on the other side
Squaring off
– Use when changing directions and crossing a surface with gaps
– Place back “squared” against object to determine line of direction away from the object
– In doorway, place a hand on the jamb on each side

Question 39

Recognize proper self protective technique.

Answer 39

Upper Hand and Forearm
– Arm flexed to shoulder level with forearm parallel to floor
– Elbow flexed at 90 degrees
– Wrist and fingers extended
– Fingers aligned to opposite shoulder
– Palm facing out
– Arm and hand relaxed to absorb shock
Lower Hand and Forearm
– Arm slightly flexed at shoulder
– Hand about 8 inches from body
– Arm and hand at midline
– Palm facing body
– Arm and hand relaxed to absorb shock
* Use selectively with clients
* For short distance travel, static environments
* Used to protect self from head to waist while ambulating across open areas
* Used to located objects from head to waist

Question 40

Describe the role of the leader in human guide, including how to approach someone in need.

Answer 40

Leader’s Role
** In addition to safely leading to a destination:*
– Describe the environment
– Warn of any hazards
– Glance back every now and then to ensure proper positioning
– Communication is very important
Approaching Someone in Need
* Do not assume someone needs help – even if they carry a long cane.
* Simply ask, “Would you like me to help you?”
* If the person accepts your offer of help, ask if they would like to take your arm.
* Touch the back of your hand against the back of her/his hand

Question 41

Recognize appropraite methods for handling narrow passages and transferring sides during human guide.

Answer 41

Narrow Passages:
1. Verbal communication- Announce to the person you are leading there is a narrow area ahead.
2. Non-verbal communication- Position the arm they are holding behind your back .
3. Glance back to make sur ethey are behind you
4. Modification- Have the person you are leading slide grip down to your wrist. Allows a few more inches of clearance between the two of you.

Transferring Sides:
1. Idea is to not break contact
2. Couple agrees on transfer
3. Person being led lets go with the hand that was originally holding the guide and moves up to shoulder
4. Guide extends elbow of other arm for easy target.
5. Person being led used hand placed against shoulder and slids it down the guides awaiting arm.

Question 42

What is the first step in ascending or descending stairs during human guide?

Answer 42

Toe-up to the steps and invite the person being led to do the same

Question 43

Describe proper seating procedures for a person who is blind or low vision.

Answer 43

1. The guide brings the person to the front of the chair
2. Places the person’s hand on the back of the chair
3. Describe the type of chair
4. person should explore the seat of the chair with hand to make sure nothing is on it.
5. Person turns around, backs up until they feel the back of the knees against the hair and sits down,