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Low Vision and Older Adults: An Interdisciplinary
Persepctive
Beth Barstow PhD, OTR/L, SCLVUAB Department of Occupational TherapyLow Vision Graduate Certificate Program
By the end of the session, participants will understand the prevalence and characteristics of older adults with low vision.
By the end of the session, participants will be able to state the primary conditions, visual deficits and behaviors of older adults with low vision.
By the end of the session, participants will be able to describe basic intervention strategies to enhance performance of older adults with low vision.
By the end of the session, participants will be able to describe referral sources for older adults with low vision.
Objectives
Introduction
4
Definition of Low Vision
A visual impairment severe enough to interfere with occupational performance but allowing some usable vision
5
What it isn’t… Blindness
◦ Persons who are blind have no light perception and no capability to use vision
Persons with low vision are not blind but they do not see well either◦ They inhabit a gray area between having good
vision and no vision
6
Definition of Legal Blindness
Term coined by federal government to describe visual impairment criteria qualifying persons for benefits and services
To be legally blind person must have◦ Best corrected visual acuity of 20/200 or less in
the better eye or◦ A visual field of 20 degrees or less in the better
eye
7
What is the difference between low vision and legal blindness?
8
Low vision describes the visual functioning of someone for whom regular eyeglasses or medical procedures cannot correct vision to within the normal range
Legal blindness is eligibility criterion used to qualify persons for services
9
The term legal blindness creates confusion about low vision Persons who are defined as legally blind have
varying degrees of vision loss
Persons who are blind are also included in the definition of legal blindness◦ But blindness is NOT synonymous with legal blindness
Many persons who have low vision but who are not legally blind have significant limitations in occupational performance
10
Who gets it and What causes it?
World Health Organization More than 161 million people visually
impaired (2002) 124 million people with low vision 37 million were blind
12
Low vision is primarily an acquired condition
Most persons with low vision grew up, worked, reared their families and retired as sighted persons
13
Most low vision is caused by just 3 age-related diseases ◦ Macular degeneration◦ Glaucoma◦ Diabetic retinopathy
Prevalence of the diseases increases with each decade over age 60
Account for 90% referrals to low vision clinics
Acquired Conditions
14
Share Common Characteristics Age-related
◦ Incidence increases with age◦ 1 out of 4 in the plus 80 age group
Vision loss is permanent
Chronic and progressing◦ Treatment focuses on management/prevention of
further vision loss NOT cure
15
Low vision is an issue of aging
Age is the best predictor of who will develop low vision◦ 2/3rds of persons with LV are over 65 years of
age◦ Incidence reaches 25% for adults over 85
Older adults associate low vision with aging◦ Because they see it as consequence of aging they
don’t seek out rehab
16
Because low vision occurs in older adults…..
2/3rds of older adults with low vision will have at least 1 other chronic condition limiting ADLs
When low vision combines with other chronic diseases it can significantly increase the likelihood of disability
Low vision plus diabetes= 6x greater likelihood of having difficulty shopping and socializing
Low vision plus CVD= 7x greater
17
Increased risk of depression with older-adults who have low vision.
◦ 2 to 5 times more likely to develop depression
◦ Greater than other common age-related conditions
◦ 25-30% experience clinically significant symptoms of depression
◦ About 7% of older-adults with a visual impairment meet the criteria for major depressive disorder, according to the Diagnostic and Statistical Manual for Mental Disorders
Incidence of Depression
18
Someone who has a minimal impairment is just as likely to develop depression as another with severe impairment.
Increased probability of depression in older adults who are legally blind in one eye.◦ Impairment in one eye may produce uncertainty
and apprehension about future visual abilities and possible ongoing changes.
Incidence of Depression
19
Low vision is a woman’s issue Ratio of elderly women to men is 2:1
◦ Largest number of older adults with low vision are women in their mid-80’s
Women with vision loss are more likely to live alone without in-home support◦ 75% of older men with low vision are married and
have in home support compared to 30% of women
20
Low vision is an issue of race and health disparities
African Americans, Hispanic, Native Americans, Pacific Islanders experience higher rates of age related vision loss
African Americans 5x more likely to experience glaucoma 6x more likely to experience blindness
Experience higher rates of diabetic retinopathy
21
Low vision is NOT a ticket to a nursing home
Despite age and impairment 70% of older adults with low vision live in their own home
27% of nursing home residents age 65 and older have a visual impairment ( National Nursing Home Survey, 1997)
Conditions
Age-related macular degeneration
Diabetic retinopathy
Glaucoma
Three primary conditions causing low vision in older adults
Progressive chronic eye condition affecting the macular area of the retina
Macula located in the central twenty degrees of the visual field is composed primarily of cone cells responsible for providing information regarding the color, contrast and detail of objects
Age Related Macular Degeneration (AMD)
25
Degeneration of Macula
Slit lamp image of healthy retina
26
Age Related Macular Degeneration
Slit lamp image of retina with AMD-yellow areas indicate deadretinal tissue-areas of scotoma
Affects an estimated 1.75 million people in the U.S. (EDPRG , 2004)
Estimated that incidence will rise to over 3 million by the year 2020
(EDPRG, 2004)
AMD
Dry (atrophic)- light sensitive cells in the macula slowly breakdown
Wet (exudative)- abnormal blood vessels behind the retina start to grow under the macula
(NEI, n.d.)
Two Types of AMD
Specific cause is unknown; theories include ◦ genetic predisposition◦ lack of anti-oxidants◦ cholesterol build up in the eye◦ abnormal response to inflammation
(University of Alabama at Birmingham Department of
Ophthalmology [UABDO], 2007)
AMD Causes
AMD Risk FactorsModifiable Non-Modifiable
Smoking Elevated plasma
cholesterol Hypertension High body mass index Atherosclerosis Diet high in fat and low
in antioxidants
(Guyner & Wei-Tinn Chong, 2006)
Age Race Gender
(NEI, 2011)
31
Age Related Macular Degeneration (AMD)
Causes:◦ macular scotomas◦ photophobia and glare sensitivity◦ fluctuating vision◦ slow dark/light adaptation◦ reduced contrast sensitivity◦ reduced color identification◦ reduced visual acuity
National Eye Institute
Difficulty with activities requiring ability to see:◦ Detail◦ Color◦ Low contrast◦ Manage bright light and glare◦ Adapt to fluctuating light levels
AMD and Occupational Performance
34
Diabetic Retinopathy
Diabetic Retinopathy (DR)
35
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 the surface of the retina, serious damage can be caused
Risk Factors
Non-modifiable Modifiable
Diabetes Length of time you’ve
had diabetes◦ Age related because
the longer one has diabetes, the more likely will experience DR
Undiagnosed diabetes Maintain stable and
controlled blood glucose levels◦ 120◦ Avoid spikes in levels◦ Requires strict adherence
to diet and glucose monitoring
Lower blood pressure Exercise Engage in heart healthy
lifestyle
36
Diabetes Self Management
37
Diabetic retinopathy and other eye complications associated with diabetes can be prevented with good control of blood glucose levels, blood pressure levels and regular eye care
◦ Finding from the Diabetes Control and Complications Trial (DCCT) A 10 year study ending in 1993 involving 1400
subjects Showed that keeping blood glucose levels as near to
normal as possible reduced damage to eyes by 75%
Close control of the disease is critical to preventing vision loss and damage to other systems
38
Requires◦ Regular monitoring by physician to ensure optimal
blood glucose & blood pressure management
◦ Adherence to healthy eating, exercise and medication management, lifestyle modification important
◦ A team approach to diabetes self-management is important, including a variety of health care providers
39
Diabetic Retinopathy (DR) Two types: background and proliferative
Demographics of Diabetes and Visual Impairment (CDC, 2007)
40
23.4 million people have diabetes (type 1 or 2)
8% of population1 million new cases per year7th leading cause of death in U.S.A.
7 million are adults over 6520% of older population
Higher incidence among African Americans, Native Americans, Hispanics, Pacific Islanders
Alabama leads country with highest rate of type 2
Diabetes and Visual Impairment
41
Leading cause of visual impairment & blindness in persons in the industrialized world in persons between the ages of 25-74
Nearly ½ of persons with diabetes will develop some degree of diabetic retinopathy during their lifetime (Roy et al., 2004)
◦ 21% of newly dx type 2 persons will already have developed some diabetic retinopathy
Diabetic Retinopathy (DR)
42
Most prevalent diabetic eye complication
Despite efforts towards PREVENTION, persons with T1D and T2D (BOTH) are
susceptible to diabetic retinopathy
Changes in Visual Function Associated with Diabetes
43
Reduced acuity Reduced contrast sensitivity function Sensitivity to glare Macular scotomas Peripheral field loss Night vision reduced Reduced color discrimination Double vision (diplopia) Visual fluctuation
National Eye Institute
Difficulty with activities requiring ability to see:◦ Detail◦ Color◦ Low contrast◦ Manage bright light and glare◦ Adapt to fluctuating light levels◦ Peripheral visual field
DR and Occupational Performance
46
Glaucoma
47
Glaucoma
Collection of diseases that affect the optic nerve◦ Open angle is the most prevalent type in older
adults
Called “the silent thief of sight”◦ Few noticeable symptoms until very advanced
2.2 million Americans (Eye Disease Prevalence Research Group, 2004)
48
Pathogenesis Begins in anterior chamber of the
eye
Pathogenesis◦ Normally the rate of aqueous
production equals rate of outflow and pressure within the eye is maintained between 9-21mm Hg
◦ In glaucoma increase in IOP occurs from build up of aqueous humor in anterior chamber
◦ Only outlet for pressure is optic disc
◦ Builds up pressure along optic nerve and decreases blood flow to nerve Causes permanent damage to optic nerve
49
Problem starts here
Damage occurs here
Pathogenesis of Glaucoma
50
Glaucoma continued….. Multiple causes
◦ Over-secretion of aqueous by ciliary body Exceeds capacity of trabecular meshwork in Canal of
Schlemm Rare
◦ Anatomical aberration resulting in narrow angle between iris and cornea preventing efficient drainage of aqueous Rare
◦ Scar tissue from an inflammatory process or surgery obstructs the drainage of the aqueous through the trabecular meshwork Most common cause
51
Types of Glaucoma Characterized as closed or open angle depending
on location of the compromised aqueous drainage
Can be congenital or acquired
May manifest as a primary or secondary condition◦ Primary glaucoma occurs without previous pathology◦ Secondary occurs secondary to an inflammatory process
Any form can lead to blindness
Ethnicity- African-Americans, Hispanics and Asian
Over age 60 Genetic predisposition Steroid users Eye injury Hypertension Myopia
Risk Factors
Peripheral field loss
Can be sensitive to light and glare
Advanced- central field loss resulting in reduced acuity, contrast sensitivity function, color discrimination
Changes in Visual Function Associated with Glaucoma
National Eye Institute
Glaucoma and Occupational Peformance
Difficulty with activities requiring ability to see:◦ Peripheral visual field
Mobility Attending to the larger environment
Intervention Strategies
57
How does it affect occupational performance? Low vision creates difficulty seeing small visual
details, low contrast and color
Can add other challenges like sensitivity to glare & difficulty adjusting to changing light levels, even seeing things that aren’t there (called phantom vision)
Affects a variety of vision-dependent basic and I-ADLs
58
Increase Visibility of the Task
Ensure lighting is optimal for task performance
Use contrast to increase visibility of key objects and landmarks
Minimize background pattern Magnify and enlarge Organize
59
Desired Light Qualities Even illumination
◦ No surface shadow
Maximum lumens/power
Minimum glare
Flexible placement◦ To get optimum positioning
60
Incandescent Light Most commonly used but often least effective Advantages
◦ Cheap ◦ Available in many forms◦ Design allows for optimal placement
Disadvantages◦ Glare
Bulbs put out predominantly yellow light that scatters more on the retina
◦ Spotlight effect occurs if shade is used over bulb
61
Fluorescent Lighting
Best for overheadlighting
Advantages◦ Provides even illumination◦ Newer models give soft light without strobing effect
Disadvantages◦ Some persons are sensitive to
strobing effect◦ Limited flexibility in placement
62
Halogen Lighting Used for task and room
lighting
Advantages◦ High quality light◦ Minimum glare◦ Even illumination◦ Energy efficient
Disadvantages◦ Hot light◦ Reduces flexibility in
placement Must avoid flammable
materials Can’t place too close to client
Torchiere lamp
Reading lamp
63
Full Spectrum Lighting Combines all colors of spectrum to provide
pure white light; very similar to natural sunlight
Advantages◦ High quality light◦ Non glaring
Disadvantages◦ Not as readily available in all stores◦ More expensive than other bulbs
64
Positioning the Light Source
Always behind person if possible
Eliminate shadows on surface
As close to task as person can tolerate
65
Use Contrast to Increase Visibility of Key Components of Task Items
Yarn placed against a dark bluelap blanket to increase visibilityMilk in a black cup
66
More examples
Place setting without contrast Place setting with contrast
Reversible black and white cutting board
67
More examples
Use dark measuring cupsfor flour, sugar and lightfor molasses, brown sugar,vanilla. Mark increments onpyrex cup with bright orangehigh marks.
Bright red tape used to mark handle on tea kettle
68
Minimize Background Pattern Like static on a radio, makes it more difficult
to locate item needed
Use solid colors on background and support surfaces
Eliminate clutter
When you can’t eliminate pattern, increase contrast of key structures
69
Use solid color for background surfaces
Note increasedvisibility withplain background
70
Reduce and eliminate clutter
Cluttered junk drawerOrganized, clutter free utensilshanging on a grid
71
Use Hands Free Magnification
Chest magnifier
Magnifyingmirrors
Big Eye magnifier
72
Enlarge
73
Organize
No organization Items grouped by type on separate shelves; handles marked with contrasting tape
Creating Visible Reading Materials
Sources: Arditi, A. (Making text Legible: Designing for people with partial sight http://
lighthouse.org/accessibility/legible/
Kitchel, E. (APH Research: Large Print Guidelines http://www.aph.org/edresearch/lpguide.htm
Low vision readers More susceptible to changes in text quality
◦ Letter size, contrast, spacing, color of text, color of page and text luminance
Readers with normal vision can tolerate poor quality print and read in low lighting BUT…
Size Enlarge text size as much as possible
◦ Most persons prefer to read at print sizes 3-5 points greater than their minimum resolution
◦ Minimum print size should be 16-18 points or larger
Contrast Maximize print contrast
◦ Normally sighted persons can tolerate a significant reduction of contrast and still resolve print but low vision readers cannot
Avoid all color contrasts but black and white◦ Red and white or blue and white is less visible
Some indication that low vision readers do best with
White on black
But
Black on White
is more familiar and esthetically pleasing
The cow jumped over the moon….(Arial)The cow jumped over the moon…(Courier)
Font
Avoid condensed font
Choose font with increased spacing between words◦ Assists person to find beginnings of words
Font Avoid superfluous font styles
Serif Times roman font
Sans Serif (block)
Geneva font
Bolded typeface is more readable
Style Use familiar typeface
◦ Combination upper and lower case letters (Mixed Typeface) is more readable than ALL CAPS Slanted Text
Line spacing◦ A minimum of 1.25 spaces between lines◦ or 25-30% of the point size
Format
Make headings larger and bolder to set them apart from the text
No columns
No divided words
Use extra white space to separate sections
Extra wide binding on reading material makes it easier to lay the magnifier flat on the surface
Paper Avoid glossy paper
◦ Reflects light off of page and creates glare
White, ivory, cream or yellow colors-avoid dark colored paper
Graphics High quality full color or black line art
Avoid shaded drawings
Don’t overlay print on graphic
Referral
86
Professions Providing LVR Ophthalmologists Optometrists Orientation and Mobility Specialists Certified Vision Rehabilitation Therapists Certified Low Vision Therapists Teachers of Visually Impaired Occupational Therapists
Questions?
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