Beth Barstow PhD, OTR/L, SCLV UAB Department of Occupational Therapy Low Vision Graduate Certificate...

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

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Definition of Low Vision

A visual impairment severe enough to interfere with occupational performance but allowing some usable vision

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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

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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

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What is the difference between low vision and legal blindness?

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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

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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

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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

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Low vision is primarily an acquired condition

Most persons with low vision grew up, worked, reared their families and retired as sighted persons

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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

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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

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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

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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

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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

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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

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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

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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

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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)

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Degeneration of Macula

Slit lamp image of healthy retina

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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)

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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

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Diabetic Retinopathy

Diabetic Retinopathy (DR)

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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

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Diabetes Self Management

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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

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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

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Diabetic Retinopathy (DR) Two types: background and proliferative

Demographics of Diabetes and Visual Impairment (CDC, 2007)

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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

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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)

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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

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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

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Glaucoma

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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)

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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

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Problem starts here

Damage occurs here

Pathogenesis of Glaucoma

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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

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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

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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

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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

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Desired Light Qualities Even illumination

◦ No surface shadow

Maximum lumens/power

Minimum glare

Flexible placement◦ To get optimum positioning

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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

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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

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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

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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

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Positioning the Light Source

Always behind person if possible

Eliminate shadows on surface

As close to task as person can tolerate

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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

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More examples

Place setting without contrast Place setting with contrast

Reversible black and white cutting board

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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

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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

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Use solid color for background surfaces

Note increasedvisibility withplain background

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Reduce and eliminate clutter

Cluttered junk drawerOrganized, clutter free utensilshanging on a grid

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Use Hands Free Magnification

Chest magnifier

Magnifyingmirrors

Big Eye magnifier

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Enlarge

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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

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Professions Providing LVR Ophthalmologists Optometrists Orientation and Mobility Specialists Certified Vision Rehabilitation Therapists Certified Low Vision Therapists Teachers of Visually Impaired Occupational Therapists

Questions?