Low Vision Rehabilitation for Older Adults

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Low Vision Rehabilitationfor Older Adults
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What is low vision?

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

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What is Legal Blindness?

• A termed coined by federal government to qualify
  persons for services
• 20/200 or less, best corrected acuity in the
  better eye or
• 20 degree or less, visual field

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Impairment Levels (WHO)

• Normal 20/20-20/25
• Near Normal 20/30-20/60
• Moderate 20/80-20/160
• Severe 20/170-20/400
• Profound 20/500-20/1000
• Near Blind 20/1001-20/2500
• Blind-no light perception

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Primary Low Vision Diagnoses

• Macular Degeneration
• Glaucoma
• Diabetic Retinopathy
• Together these 3 account for 80 of all referrals
  to low vision clinics

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Disease Characteristics

• Age related
• Chronic and progressive
• Vision loss is irreversible
• Tx consists of management not cure

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Low Vision Demographics

• 2/3rd are over the age of 65
• Most persons with low vision grew up, worked,
  reared their families, and retired as sighted
  persons

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Low Vision Demographics

• Incidence reaches 25-30 in adults over age 85
• For persons over 70, vision loss ranks 3rd among
  chronic conditions that cause ADL limitations

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Low Vision Demographics

• 2/3rds of low vision elderly have a secondary
  chronic condition which impairs occupational
  performance

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Low Vision Demographics

• Vision Loss is a womans issue
• Vision loss is a race/ethnicity issue
• Vision loss is a socio-economic issue

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Blindness System

• Integrated as a system after WW II
• Uses an educational/vocational model
• Primary providers
• Rehabilitation Teachers
• Orientation Mobility Specialists

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Service Providers

• Private, charitable organizations
• Veterans Administration
• State Vocational Rehabilitation

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Rehabilitation Act of 1973

• Established state commissions/divisions for the
  blind
• Amended in 1978 to add independent living skills
  training for older adults through title 7
• Currently funded at 11million dollars for entire
  country

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Health Care System

• Services reimbursed through medical insurance
• Prior to 1991 primary providers were
• Ophthalmologists
• Manage disease, attempt to prevent further vision
  loss
• Optometrists
• Prescribe optical devices

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Critical Milestones

• 1991, HCFA acknowledged that vision loss is a
  physical impairment
• Enables reimbursement for services provided by
  licensed health care providers
• On a state by state basis through the Medicare
  fiscal intermediaries
• Brought O.T. into the field
• May 2002, CMS issued a program memorandum
  extending coverage of rehabilitation services to
  beneficiaries with low vision

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Healthcare vs. Blind System

• B/S
• Chronic funding and personnel shortages limit
  availability of resource
• Children and working age adults are the primary
  treatment focus
• H/C
• Services are more widely distributed, funding is
  guaranteed
• Elderly are the primary focus of treatment

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O.T. as LVR Provider

• Good discipline to bridge the gap
• David vs. Goliath
• 98,000 to approximately 2,500
• Vision Rehabilitation Act
• HR 2484

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Normal Age Related Changes in Vision

• Changes begin in the 4th decade
• Become significant in the 9th decade

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Reduced Visual Acuity

• Static acuity
• Decreases to 20/30-20/40
• Prevalence 40 by age 70
• Dynamic acuity
• Decrease may be due to reduced OM control

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Loss of Accommodation

• A.k.a. presbyopia
• Result of compacting of protein fibers in center
  of lens
• Lens thickens and loses flexibility
• Occurs gradually beginning in 40s
• Creates need for bifocal

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Floaters

• Strands of protein which float in vitreous
• Float more easily in old eye because vitreous is
  more fluid
• More noticeable in bright light
• Generally benign unless accompanied by bright
  flashes of light or significant increase in number

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Dry Eyes

• Lacrimal glands do not make enough or make poor
  quality tears
• More prevalent in women
• Can be exacerbated by medication
• Causes itchiness, burning, decreased acuity
• Treated with artificial tears or surgery

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Increased Need for Light

• Pupil diameter decreases
• A.k.a. senile miosis
• Lens thickens becoming more yellow
• Combined-these two conditions reduce the amount
  of light coming into eye
• 80 yr old person needs 10x as much light as an
  average 23 year old

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Susceptibility to Glare

• Lens and cornea become less smooth
• Lens vitreous develop protein strands
• Combine to cause light scatter
• Increased discomfort and disability
• Lose acuity under glare condition
• Also takes longer to recover from glare

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Reduced Dark/Light Adaptation

• Takes longer to reform and store pigments
• Never reach same level of dark adaptation as
  younger person
• More difficult to go from bright to dark than
  dark to bright

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Reduced Contrast Sensitivity

• Caused by changes in color and density of lens
  and decreased pupil aperture
• 75 year old needs 2x as much contrast as younger
  person
• 90 year old needs 6x as much contrast

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Reduced Color Perception

• Caused by yellowing of lens
• Decrease in sensitivity at violet end of spectrum
• White objects may appear yellow

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Reduced Visual Field

• Changes in facial structure
• Nose grows??
• Orbit loses fat and eye sinks in

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Reduced Visual Attention

• Decline in ability to
• Attend to objects in complex, dynamic arrays
• Simultaneously monitor central and peripheral
  visual fields
• Diameter of visual field decreases
• 90 yr olds-40 have an attentional field of less
  than 20 degrees

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Changes with Low Vision

• Markedly reduced visual acuity
• Markedly reduced contrast sensitivity
• Reduced color discrimination
• Visual field deficits
• Intolerance to light and glare
• Visual aberrations-metamorphopsia
• Benign visual hallucinations-Charles Bonnet
  Syndrome

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Macular Degeneration
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Wet Form

• Characterized by neovascularization
• Blood vessels hemorrhage and destroy retina
• Usually bilateral
• Can be aggressive
• Makes up 10

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Dry Form

• RPE cells begin to break down
• Drusen develops on retinal surface
• Often unilateral
• Slowly progressing
• Can be precursor to wet form

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Both Cause Central Scotoma
Scar tissue forms over fovea
Image is blurred in area of scar tissue
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Preferred Retinal Locus

• Develops when fovea is destroyed
• Development starts within 24 hours
• Acts as pseudofovea directing fixation
• Located in less sensitive retinal tissue
  requiring need for magnification
• Person may not be aware of it

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Medical Treatment Options

• Wet form
• Laser photocoagulation
• Photodynamic Therapy (PDT)
• Dry Form
• No definitive treatment
• Vitamin regimen for both
• Zinc, E, lutein

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Glaucoma

• Chronic open angle
• Drainage system clogs
• Causes build up of intraocular pressure
• Destroys optic nerve
• Can lead to blindness

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Treatment

• Eye drops
• Argon laser trabeculoplasty (ALT)
• Surgical Trabeculectomy

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Eye Conditions Associated With Diabetes

• Premature presbyopia
• Cataracts
• Glaucoma
• Paralytic strabismus
• Corneal disease
• Retinopathy

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Diabetic Retinopathy
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Treatment Options

• Best treatment is prevention
• Maintain blood glucose at 125
• Pan retinal photocoagulation
• Vitrectomy

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Cataract

• Opacification of the lens
• So common that some degree of cataract is
  expected by age 70
• Reduces
• Acuity
• Contrast sensitivity
• Increases glare
• Tx Intraocular lens replacement (IOL)

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Homonymous Hemianopsia
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Low Vision Exam

• Focus
• on use of remaining vision
• CNS adaptation to vision loss
• Four visual functions measured
• Acuity
• Contrast sensitivity
• Visual field
• Color vision

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Acuity Testing
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Contrast Sensitivity Test
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Perimetry Testing
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O.T. Evaluation

• Identify strengths and weaknesses in patient
  performance
• Assess CNSs ability to adapt to vision loss
• Ability to locate and use PRL
• Preferred retinal locus

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Awareness of Scotoma
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Scotoma Influence on Performance
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Vision loss is a profoundly personal experience
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Vision loss does not occur within a vacuum

• Social context
• Cultural context
• Environmental context
• Health context

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Occurs slowly over a long period of time

• Often difficult for person with vision loss to
  discern boundary between normal vision and
  beginning stages of impairment
• Does not create a sudden crisis that must be
  immediately dealt with by family

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• Most important factor in a successful adjustment
  to vision loss is social contact
• Needs at least one consistent quality contact

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• Older adults who lose vision want to continue
  activities that are important to them
• Their ability to use compensatory strategies to
  continue valued activities is quite good
• Families are often unaware that change is
  occurring until significant decline

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• Ability to continue a few activities can
  significantly improve or sustain quality of life
• Rehabilitation outcome must be measured in two
  domains
• Occupational performance
• Quality of life

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Identifying and Setting Goals

• Client driven
• Must meet Medicare requirement for medical
  necessity
• Must fit into Medicare FI guidelines for
  treatment

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Self Report Interview Format is Optimal

• Observation of ADLs is too time consuming for
  outpatient setting
• Self report gives person chance to establish
  priorities
• Observation of a few key activities is necessary
  to confirm report
• Some patients over or under estimate abilities

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Treatment Approach

• Maximize use of current visual ability
• Teach person to use vision more effectively
• Modify environment to facilitate use of vision
• May be vision user and substituter
• Multiple short term interventions often needed

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The Older Adult and Driving
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First, the facts

• By 2020 there will be 40 million age 65 plus
  drivers
• 30 million over the age of 75
• Older adults use their cars for 90 of their
  travel

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Safety Record of Older Drivers (2000-National
Center for Statistics and Analysis)

• Older people made up 9 of the population but
  accounted for 13 of all traffic fatalities and
  17 of all pedestrian fatalities
• Per miles driven, the fatality rate for drivers
  older than 85 is 9x as high as the rate for
  drivers 25-69 yrs
• Older drivers are second only to teens in crash
  fatality rates
• Most traffic fatalities involving older drivers
  occur
• During daytime (81)
• Weekdays (71)
• Involved another vehicle (76)

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High Risk Areas for Older Adults

• Night driving
• Urban and suburban intersections
• Failure to yield the right of way
• Failure to head traffic signs
• Improper left turns
• Freeways
• Highway work zones
• Older adults have the lowest proportion of
  intoxication of all adult drivers and pedestrian

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• In two vehicle accidents involving an older
  driver and younger driver
• Vehicle driven by older adult was 3x as likely to
  be the one that was struck
• 44 of these crashes both vehicles were
  proceeding straight at time of collision
• In 27 the older driver was turning left
• 6x as often as the younger driver

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Driving Demands

• Driver must see or hear the situation
• Driver must cognitively recognize the situation
• Driver must decide how to react to the situation
• Driver must execute the physical manuever
• Must complete this within miliseconds of time in
  a dynamic environment

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Age Related Changes that Affect Driving
performance

• Cognitive
• Physical
• Sensory

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Cognitive Changes
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Cognitive Changes

• Dementia
• confusion
• Reduced visual attention particularly when
  confronted with complex, dynamic environments
• Results in reduced scanning speed and incomplete
  scanning
• Difficulty dividing attention
• Difficulty ignoring irrelevant visual information
• Slower retrieval and processing of information
• Judgment
• Make errors of omission

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Physical Changes
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Physical Changes

• Reduction in neck/trunk ROM
• Reduction in muscle strength
• UE turning wheel
• LE depressing gas and accelerator
• Endurance
• Coordination and dexterity
• Reaction time

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Sensory Changes
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Sensory Changes

• Vision
• Dynamic visual acuity
• Night vision
• Glare recovery
• Reduced contrast sensitivity
• Reduced color discrimination
• Reduced peripheral visual field
• Hearing
• Discrimination
• Localization

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• Kinesthetic
• Contributes to decreased dexterity
• Vestibular
• Affects ability to perceive motion

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Independent Transportation

• Provides older adults with the ability to meet
  quantity of life needs
• And enjoy quality of life opportunities
• Older adults dread the time when they can no
  longer drive their cars
• Lose independence
• Cannot use traditional forms of public
  transportation
• Do not believe that there are other forms of
  transportation to meet their needs
• In many communities their perception is correct

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Role of O.T.

• Determine whether person should continue to drive
• Recommend modifications to vehicle, driving
  approach to decrease accident risk and increase
  safety
• Identify and provide resources for alternative
  transportation if driving cessation is necessary

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Determining Driving Capacity

• Driving history
• Trigger questions
• Do you drive?
• Have you become uneasy about your driving?
• What is it that bothers you?
• Have you had any near misses?
• What is it about other drivers that bothers you?
• Answers predicting crash risk
• Near misses
• Irritation while driving
• Change in driving ability
• Self rating of driving safety

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Determining Driving Capability..

• Medical history
• Diabetes
• Stroke
• Parkinsons
• Circulatory problems
• Heart disease
• Hearing loss
• Vision loss
• Vestibular dysfunction

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Determining Driving Capability

• Medications
• Functional performance
• If uncertain about capability refer to
• Certified Driver Rehabilitation Specialist

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Vehicle Modification

• Visibility
• Mirrors, rearview
• Control panel
• Accessibility
• Safety features
• Air bags
• Seat belts
• Automatic locks
• Keyless entry

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Driving Cessation

• DONT DUCK THE ISSUE
• An important I-ADL
• Not someones elses problem
• In some states OTs have a legal responsibility
• Be aware of your state regulations
• Consider graduated driving
• Most older adults self restrict already but may
  be possible to find safer routes or times

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Driving Cessation

• Be direct
• Vague statements let the client dodge the issue
• Listen to why the client needs to drive and offer
  alternatives taking into consideration the
  clients specific needs
• Older adults are most comfortable riding with a a
  friend or family member or hired driver
• Many older adults cannot use public
  transportation