Presentation on theme: "Occupational Therapy Role in Low Vision By Serena Speaker OTR SCLV November 8, 2013 TOTA Mountain Central Conference."— Presentation transcript:
Occupational Therapy Role in Low Vision By Serena Speaker OTR SCLV November 8, 2013 TOTA Mountain Central Conference
Objectives 1.Participant will understand basic anatomy of the visual system and primary low vision conditions affecting older adults. 2.Participant will be able to describe how low vision conditions influence occupational performance. 3.Participant will be able to compare and contrast the role of the occupational therapist specialist and generalist in low vision rehab. 4.Participant will demonstrate techniques to improve ADLS function with low tech devices.
What is low vision ? Definition of low Vision -a visual impairment severe enough to interfere with occupational performance but allowing some usable vision Legal Blindness (used to qualify persons for benefits and services) Best corrected visual acuity of 20/200 or less in better eye (BE) or visual field of 20 degrees or less in the better eye Source: Warren, Mary, MS, OTR/L, FAOTA (2008) Low Vision: Occupational Therapy Evaluation and Intervention with Older Adults, Revised Editin. Bethesda, M. AOTA Press.
Low vision is primarily an acquired condition that is an issue of aging 2/3 are over age 65 30% over age 75 Most are caused by 3 age related conditions- Macular Degeneration, Glaucoma, Diabetic retinopathy These account for 90% of low vision referrals
Visual Perceptual Hierarchy Seven levels of visual processing Permission From Mary Warren PhD, FAOTA, OTD
Foundation Level 1. visual acuity 2. visual field 3. oculomotor control
Third Level Scanning-ability to look side to side
Level Four-Pattern Recognition CNS must have high quality, accurate visual input to complete object recognition. 1.Visual acuity ensures the clarity of visual input 2.Visual field integrity ensures the presence of vision-that all of the visual input from the environment is represented 3.Oculomotor control ensure that visual information is acquired rapidly and accurately when the body is in motion or at rest for perceptual stability
Level Five Visual memory-the ability to recall or match the visual object to one’s memory. When an R is an R and is the first letter in Run. Or a picture or viewing a water glass means that there is a memory that means this glass of water will be able to quench my thirst.
Level Six Visuocognition- the ability to use the visual memory and then relate to past experiences on a cognitive level. The ability to recognize a bank check register and then be able to record the check, determine the balance in the check book and then reconcile the balance with the bank statement. Visual tasks that require cognitive input on a high level of processing from the initial visual input.
Level Seven Adaptation through Vision 1. Solve Problems 2. Formulate plans 3. Make decisions Source: Warren, Mary, MS, OTR/L, SCLV.FAOTA and Elizabeth Barstow, MS, OTR/L, SCLV (2011). Occupational Therapy Intervention for Adults with Low Vision, Bethesda, Md, AOTA Press.
Low vision is issue of aging Older adults associate low vision with normal aging process 2/3 have at least one other chronic medical condition (LV with diabetes=6X greater likelihood of problems shopping and socializing, LV with CVD=7X) Woman’s Issue-more likely to live alone, 75% of men with low vision are married and have in-home support compared to 30% for women
ICD-9 CMS Definitions of Low Vision and Blindness table. Individuals will not meet CMS medical necessity requirements unless Visual Acuity is worse than 20/60 in the better seeing eye or visual field less than 20 degrees. OTs provide services under Part A-acute care, Part B or Home Health umbrella. Additional credentialing is encouraged: SCLV by AOTA and or CLVT by ACVREP.
Occupational Therapy Practice Framework (AOTA) published 2002, revised in revised in 2008 Ecology of Human Performance Model published 1994 by Dunn, Brown & McGuigan describes the domain and processes that define occupational therapy practice and outlines the OT evaluation and intervention process. Investigates relationship between the person, context, tasks, performance, therapeutic intervention.
Occupational Areas Activities of Daily Activities Instrumental Activities of Daily Living Rest and sleep Education Leisure Play Social Participation Work
Instrumental Activities of Daily Living Shopping Accessing transportation Locating correct aisle/item Reading prices Making change Making grocery list Money management Reading bills/financial statements Completing check, money order Debit transaction Maintaining financial ledger Addressing/mailing bills Computer bill payment Identifying money Leisure Sewing, quilting, needlework Bingo Card games Woodworking Fishing Automotive repair
Reading Activities Informational Reading Pleasure Reading Newspaper Magazines Newspaper ads E-mails Stock quotations Books TV guide E-books Recipes Daily devotionals Food labels Cards and letters Medication labels Menus Telephone directory Address Book Incoming mail Bank receipts/statements Checkbook ledger Watch or clock face Street signs Aisle marker/store signage
Home and Community Activities Home Maintenance Cleaning Setting dials on washer/dryer Yard maintenance Car maintenance Minor household repairs Ironing Thermostat adjustment Community Activities Accessing transportation Recognizing acquaintances Maintaining orientation in unfamiliar places Locating public restrooms Eating out in restaurants Negotiating curbs, steps, etc Avoiding collisions
Two step process to develop an intervention plan occupational profile occupational analysis OT evaluates FUNCTIONAL vision How it hinders and facilitates occupational performance to define rehab potential
Results of A Good Evaluation 1. Identify limitations in occupational performance 2. Identify factors that contribute to the limitation in occupational performance 3. Determine if intervention is necessary 4. Identify most appropriate intervention to achieve optimal outcome
Anterior Visual System Cornea Iris Lens Choroid (blood supply) Ciliary Body: 2 structures Ciliary muscles shape lens, controlled by CN III Ciliary process - secretes aqueous in anterior chamber
Anterior Visual System Anterior Chamber: space that is filled with clear watery fluid between the back surface of cornea and front surface of the vitreous Aqueous: produced by ciliary body in posterior chamber and circulates through anterior chamber continuously produced and drained away while maintaining the shape and pressure within the eye
Overall function of brain is to filter, organize and integrate sensory information to make an adaptive response to the environment. CNS is devoted to taking in sensory input, analyzing it and responding to it. Vision is primary sensory system to acquire information about environment. 80-90% of learning occurs through visual channel 1/3 to 1/2 of brain devoted to visual processing
Most far reaching sensory system alerts us to danger or pleasure enables us to be anticipatory, plan for situations Supplies speed in informational processing tells us exactly what is going on instantly identify objects with vision Can use other senses but not as quickly Example: World Trade Towers
Size up situations first impressions are important avoid certain people Make decisions where to sit in a room what to select from salad bar Solve problems want to see the problem so we can solve it with visual memory of a previous event previous problem can help solve a new one Interpret social interactions facial expressions Elicit and guide movement Maintain postural control warn of upcoming obstacles to navigate around objects
Because of the importance of vision to the brain, a person with vision-no matter how limited-will ALWAYS attempt to use vision to adapt and complete activities Biggest challenge is that low vision is a hidden disability and its symptoms are often attributed to other causes we identify low vision if the person has a white cane or dog guide
Reduced visual acuity to 20/30-20/40 Dynamic acuity decreases affects gaze stability more visual blur Loss of accommodation AKA; Presbyopia; lens thickens and loses flexibility bifocals Floaters: strands of protein that float in vitreous generally benign unless accompanied by bright flashes of light or significant increase in number Dry eyes lacrimal glands decrease secretion medication exacerbates condition, treat with artificial tears
Increased need for light pupil diameter decreases, lens thickens and yellows 80 yo needs up to10X more light than 23 yo Glare susceptibility lens and cornea become less smooth protein strands cause light to scatter increased discomfort Reduced dark/light adaptation more difficult to go from bright to dark than dark to bright since takes longer to reform and store visual pigments Reduced Contrast Sensitivity caused by changes in color, density, size of pupil 75 yo needs 2X as much contrast as younger person 90yo needs 6X
Macular Degeneration Other names for this condition: Senile macular degeneration, Atrophic macular degeneration (AMD), Age related macular degeneration (ARMD) Two forms-chronic and advanced (dry/wet) Caucasians more susceptible NEVER results in blindness-disease of central vision-cone retinal cells 60 to 90% of referrals to low vision clinic
Two types 1. Chronic: dry or atrophic type 90% 1. Progressive: wet or hemorrhagic type 10% Attacks cone cells Both types cause macular scotomas (blind spots) photophobia (light sensitivity) fluctuating vision slow dark/light adaption
Vision with Macular Degeneration Normal vs Macular Degeneration view
Injected into vitreous cavity Lucentus (40X cost of Avastin) approved in 2006-4 wks Avastin-used off label- every 4 weeks Macugen-approved in Germany 2006- every 6 weeks Eylea-FDA approved November 2011 Eliminate existing abnormal blood vessels and turn off signal for additional vessels to develop Works for several weeks to months: repeated injections if necessary Lost vision may be recovered if administered at first sign of new blood vessel formation
Avastin and Lucentis are equivalent in treating Wet AMD Avastin most frequently used drug for wet AMD Two year clinical trial with results published 04-13-12 by National Eye Institute-NIH Long term results with either drug resulted in robust and lasting improvement in vision As needed dosing vs monthly treatment only yielded ½ line better acuity in 2 year trial As needed dosing required 10 fewer eye injections with similar results, many pts may choose this option Lasting improvements in vision with there two drugs is extraordinary At two years, 2/3 of pts had driving vision (20/40 or better) while only 15% of pts retained similar visual acuity with previous tx Source; www.nei.nih.gov/news/pressreleases/043012.asp
Pathology gradual destruction of cone cells Drusen develops on surface of retina where atrophy is occurring Gradual progression Often unilateral for many years No conclusive medical treatment-eye vitamins may help
Side effect of Diabetes- most dangerous as can take vision rapidly, higher prevalence in African American, Native American, Hispanics, Pacific Islanders Accounts for 9% of low vision referrals Diabetes has multiple effects in eye-effects entire retina and can cause any level of vision loss including blindness Only common eye disease causing varying patterns of vision loss because it affects blood vessels that support entire retina 50% increased risk for cataracts for people over 50, with increased complications from cataract surgery 2X incidence of chronic open-angle glaucoma than person without DR
Disease of optic nerve although it starts in the Anterior Chamber of the eye Can result in blindness-most feared Required good control with drops and frequent eye exams Higher incidence in African Americans-significant visual loss 13% of low vision referrals
Glaucoma continued Group of eye diseases pressure inside eye is too high traumatic angle closure low-tension or open-angle glaucoma (most common) all cause damage to optic nerve 50% of people with condition do not know they have glaucoma
Glaucoma Aqueous production should equal outflow to maintain pressure within eye between 9-21 mm HG Build up of pressure in anterior chamber only outlet is optic disc pressure decreases blood flow to nerve
Cloudiness or opacification of lens Occurs with advancing age Dulls color Blurs visual detail throughout visual field Affects distance vision before near but eventually dulls both Cataract surgery is most common surgery in US with natural lens removed and a synthetic intraocular lens implanted through 3 mm incision.
Other vision deficits; Parkinson’s Disease-difficulty with upward gaze and convergence-necessary for reading. Hemi Field defect with normal acuity-result of CVA, TBI, brain tumor: hemianopsia, quandrantanopsia with reading difficulty, neglect, short term memory issues with loss of letter and word recognition. Alzheimers disease-defects in color, depth and movement perception. Refractive errors-myopia (near sighted), hyperopia (far sighted), astigmatism (cornea problems).
Usually completed by low vision ophthalmologist or optometrist Completed not to determine what is gone but what vision remains Functional Vision Always assess acuity, contrast sensitivity, visual field Informal assessment-questioning dark light sensitivity, glare light sensitivity (photophobia), phantom vision color vision
Ability to see small details at specific distance Two types Distance/Intermediate Reading In USA use Snellen equivalent fracture 20/20 is normal what a normal person can see at 20 feet Actually it is the ratio of the test distance at which the smallest optotype subtends 5 minutes of visual arc (or angle) or minimum angle of resolution-MAR for short
Factors to be considered when Assessing Visual Acuity Lighting Contrast Specific chart used Numbers of targets at each acuity level Spacing of targets Difficulty of the targets being identified (ie, letters, numbers, pictures, etc) Single letter verses reading acuity Type of letters (ie, block, serif, etc) Ease with which the targets are identified Expressive as well as receptive language skills Cognitive functioning Eccentric viewing (body position, eye/head posture) Source: Scheiman, Mitchell, OD, FAAO (2002). Understanding and Managing Vision Deficits-A guide for Occupational Therapists. Thorofare, NJ. Slack
Measurement in the normal to near normal acuity range-stops at 20/200 (big E) No measurement for vision worse than 20/200 or anything between 20/100 & 20/200 Subjective measurement below 20/200: count fingers x number of feet (CF at X feet), hand movement (HM or HMO), Light perception only (LPO), no light perception (NLP)
Discrete assessment in low vision range intermediate distance of 1 meter can measure to 20/1200 best chart uses logarithmic progress ETDRS chart (lomag Chart) is Gold standard same # of optotypes per line spacing between letters and rows are proportional to size of letter 1 log unit between each level enables letter by letter measure Test procedure: dominate eye, non-dominate, together Intermediate Acuity
Ability to read text tests near acuity to 20/400 requires accommodation Variety of test cards Warren reading chart MN read acuity chart Lighthouse Children Test procedure: reading glasses on; use both eyes; distance of 16 inches/40 cm; center at clients midline; start at top and read down as possible; record acuity at last line of text accurately read
Determine level of visual impairment for billing services-OT paid on level of acuity Snellen of metric acuity can be used to determine minimum magnification to read 1M size print-requires 20/50 to read newspaper reduce until denominator is 1 EX: 20/200=1/10 magnifier needed at least 10X Strength of Magnifier Size M units read divided by size of goal M unit EX: read 50M and want to read 1M Newspaper need 50X magnifier
AKA-low contrast acuity Not Specific for certain disorders Ability to see item as it degrades in contrast from its background most environmental features are low contrast decreases with any deterioration of macular function faces very difficult person will have difficulty detecting low contrast feature such as water on floor
Why two patients function differently with same Snellen Acuity. “This difference can usually be predicted with contrast sensitivity testing. In general, a poor contrast indicates that the clinician should give more attention to glare control, contrast of viewing materials and illumination. These factors are often more important than magnification.” Source: Freeman, Paul B. OD, FAAO and Jose, Randall T. OD, FAAO. (1991) The Art and Practice of Low Vision. Newton, MA. Butterworth-Heinemann-division of Reed Publishing (USA).
Several test formats Pelli-Robson gold standard-measures from 100% to 1% which measures threshold contrast. But threshold contrast is not a prevailing condition for ADLs. Lea Number Low Contrast Chart measure 5 levels: 25% to 1.5% clients begin to have problems at 25% level-see index Lea test instruction for Lea chart-reading glasses, both eyes, center chart at 40cm at midline, explain that test uses numbers, identify first # each line, continue until unable to read entire line, go back to previous level and read all #s
Colenbrander Mixed Contrast Reading Card High contrast (HC) and 10% low contrast (LC) (What is the smallest letter size that can be read at intermediate contrast-assures the high contrast and low contrast are presented at the same distance with the same illumination) More realistic for ADL performance are stimulus of intermediate, low contrast than high contrast stimulus of an optotype against an empty background( ie Pelli-Robson, Mars) Must be careful about low contrast situations (night driving, stepping off curbs) to avoid serious accidents. Awareness of contrast problems can lead to many simple ADL adaptations. A HC-LC difference of 1-2 lines is within normal limits, 3-5 lines moderate decrease,6-8 lines marked decrease, regardless of visual acuity will indicate problems. This can provide a strong demonstration for the patient. The effect of increased illumination is also easily demonstrated. Source: Envision 2012, Mixed contrast Measurement, August Colenbrander, MD.
Additional tests Visual field; central and peripherial
Additional Tests continued Scotomas-blind spots in central and para-central visual fields Color vision Dark/light adaptation Glare sensitivity Phantom vision-Charles Bonnet Syndrome
Acuity-intermediate with EDRST chart, Warren number test Acuity-reading or near Warren reading card, MNread card Contrast Sensitivity Function-LeaNumber Low Contrast Chart, Colenbrander chart
LAB-Intermediate Acuity Test each eye with use of patch or occulder and then both eyes-compare the results. Are they the same or different? Why? ETDRS Chart Warren Number Chart Try the test with simulators and see if your result are different.
Lab: Near/Reading Acuity Warren near test Tumbling “C” (What type of client would this test be appropriate for?) May wear glasses and use both eyes. Client may move closer than 16” or 40 cm but must notate on results.
Lab: Contrast Sensitivity Lea Number Do not touch numbers on chart-use cloth or yellow tip pointer to not damage the test. Read initial number of each line until unable and then return to prior level and read all of numbers. Try again with different types of visual simulators. Colenbrander Read chart with dark and light print forming sentences. Where does your client have issues? Are there more than 2 lines of difference between reading the dark and light (10%) parts of each sentence? Try with different simulators-any problems?
Basic approach-Enable person to effectively use remaining vision to complete needed ADLS and IADLs Accomplished by modifying the task and environment to increase visibility Assessment combines self-report with observation of selected task; person will often over or under estimates skills, reluctant to admit limitation with task performance Self-Report Assessment of Functional Visual Performance Profile-SRVFVP (available on line)
Average older adult spends 80% of day at home Home lighting does not meet recommended levels (Glaucoma and visual functions study: only 2 of 117 participants met recommended lighting levels!!!) Improved lighting increased Visual Acuity by 2-3 lines in 63% of study participants Person with macular disease performs better with additional light because it allows use of relative scotomas. Desired qualities-even illumination, maximum lumens, minimum glare, flexible placement for optimum positioning Source: Envision 2012, The Home Environmental Lighting Assessment, Monica S. Perimutter, OTD, OTR/L, SCLV
The Lighter Side of Low Vision Terms for Basic Lighting Illumination The distribution of light on a horizontal surface. Illumination is measured in footcandles (ftcd, fc, fcd) English system or lux in the metric SI system. Lumen The measurement of light emitted by a lamp. Illuminance Is a useful measure of a light source Usually diminishes with distance and angle Independent of surface properties (color, finish, texture)
Footcandle A measurement of the intensity of illumination: a footcandle is the illumination produced by one lumen distributed over a 1-square-foot area. Color Temperature The color of the light source. Color temperature is measured in Kelvin (K) temperature. Color rendition How colors appear when illuminated by a light source. The Color Rendition Index (CRI) is a 1-100 scale that measures a light source’s ability to render colors the way sunlight does.
Glare The excessive brightness from a direct light source that makes it difficult to see what one wishes to see. A bright object in front of a dark background usually will cause glare. Glare can be difficult to control when providing light for people with low vision. Contrast Contrast is the difference in brightness between the background and text. 100% contrast is pure black on pure white. Many eye charts have > 80% contrast. Reading materials such as newspapers or paperback books have low contrast. *Contrast is property of the page: lighting or filters do not change it. It is a property of the reflectivity of the page and ink. Lighting can change perceived contrast, but not actual contrast.
Factors affecting lighting recommendation Lighting needs are different for everyone due to : Age Medical conditions Eye conditions What task is being performed What the environment is like (current lighting available)
Age and Lighting Less light reaches the retina in an aging eye than it does in a younger eye. Pupil size reduces with age so less light enters the eye. The lens, which is normally clear in a young person or pre-presbyope, yellows and thickens with age, also impeding the transmission of light.
*Ages 61-79: Ambient (general) illumination should be about three to four times higher than is typical for a pre-presbyope. *30 foot candles are recommended for general room lighting. *Studies have shown that a 65 year old may need up to 15 times as much light to read as a 10 year old. *A visually impaired person may need three times as much light to read as someone the same age who is not visually impaired. Source: http://www.ligthhouse.org/eye-health/the-basic-of-the-eye-aging/lighing: http://www.ecmag.com/section/lighting/lighting-through-agers\: http://www.ecmag.com/section/lighting/lighting-through-agers\ http://www.americanlightingassoc.com/about-ALA/Press-Release/featured-article---Aging-Eyes/aspx
Common Environmental Illuminance values Outdoor Starlight.0001 lux Full moon.27-1 lux Very dark overcast day100 lux Overcast day1,000 lux Full daylight (not direct sun)10,000-100,000 lux Indoor General residential lighting50-100 lux Residential dining room100-200 lux Residential reading200-500 lux Classroom or brightly lit exam room500-1,000 lux ***A brightly lit room is 10-100x dimmer than daylight.
Lighting Guidelines for Specific Tasks Examples of tasks that will be most impacted by illumination. General lighting: 53.76 lux Kitchen (counter): 322.56 lux Reading (casual): 322.56 lux These are recommended level for patients with normal vision. See Appendix 1
Indoor Lighting Ambient lighting-general lighting in a room Overhead lighting should be available in every room if possible Overhead light fixtures should be deliberately positioned where a task is performed Dimmer switches can help to adjust to different lighting levels and time of day Over head track lighting allows for even illumination in a room Vertical blinds on windows allows natural sunlight in a room Recessed lighting can be used over specific work areas such as the sink or counter Painting walls a lighter shade will allow maximum efficiency of illumination
Task Lighting-specific lighting to a task or area Task lighting is positioned closer to one’s material to increase light intensity without having to increase the bulb’s wattage. Task lighting maybe more crucial if renting vs owning home. Adjustable floor, table, or wall mounted lamps should be used close to where you are performing various tasks-gooseneck or swing-arm floor or desk lamps allow the closest, most efficient task lighting.
If reading-task lighting comes from behind or the side of the better seeing eye (if applicable). Have the light close to and facing your materials. Sit with your back facing the window so sunlight will be on the task you are performing. Have light slightly below eye level to prevent glare. If writing –have your light coming from the front and on the side opposite your writing hand.
Outdoor Lighting Walkways should be lit with path lights of overhead flood lights Awnings or open garage entrances allow for adjustment of lighting levels from outdoor/indoor for increased safety Porches/balconies should have light fixtures positioned so light shines in center of the proper area Clean bulbs and globes/fixtures regularity for increased lighting and reduction of glare Landscape lighting can help with safety Reflective tape can be use to mark steps or solid surface changes
Standards to measure lighting A light meter measures illuminance (the amount of light hitting the detector) in lux or foot candles. A light meter is recommended when performing ambient or task lighting assessments/providing recommendations Light meters are commercially available and range in cost form $16 to $300
Lighting with Color Temperature Color temperature is a measure of how “warm” or “cool” the light is Lighting with lower color temperature are described as “warm” while higher color temperatures are described as “cool” (description is the color not the temperature) ***(Review of wavelength spectrum and visible light spectrum with color violet at wavelength 400-420nm up to color Red at wavelength 620-780nm).
How the Human Retina responds to color Three types of cones: One type of cone is primarily sensitive to short wavelengths (blue) another to medium wavelengths (green) and one to long wavelengths (yellow) The yellow cone is usually referred to as the red cone.
Types of lighting Fluorescent and compact fluorescent Incandescent Halogen Full Spectrum LED Specialty bulbs Natural sunlight
Fluorescent-long tubes, common in public areas, produce glare and flicker Compact fluorescent (CFL) now used in homes for energy efficiency Incandescent-yellow light most common in homes-standard light bulb Warm light/Soft white-full spectrum and halogen are available as an incandescent bulb
Halogen-bright, white light, expensive Full spectrum-full range of colors like sunlight, can be glaring, no UV filters, available from local stores and specialty lamp stores that can produce stronger illumination
LED (light emitting diodes) white light in various shades mostly found in portable lighting devices becoming more readily available in bulbs and fixtures high efficiency low voltage (2-3.5 volts) low cost which allow use of many LEDs in a reasonable-priced light provides bright monochromatic source that could benefit those with color vision defects longer life than other light sources
Rated life for different light sources Incandescent750-1,000 hours Halogen 3,000-6,000 hours Compact fluorescent 6,000-15,000 hours LED 50,000-100,000 hours 12W LED, 17W CFL, 50W Halogen, 75W incandescent are equivalent LEDs use ¼ the power of halogen and 1/6 power of incandescent
Lux for typical sources at 50 cm- approximately 18 inches Incandescent, 75 W = 1662 lux Compact fluorescent, 15 W = 1019 Halogen, 50 W = 1528 LED, 12 W =1528 Source: Wikipedia
New labeling changes for Bulbs The new label will include the brightness (lumens-ie 380 lumens) of the bulb and the cost of operation (watt-ie 4 watts) instead of wattage (amount of energy), the color temperature (2700K=warm, 6500K=cold) (ie 2700K=warm), size of the base (must match the fixture ie-A19).
LED Bulbs: The future of Lighting for the Low Vision Patient? An instant start No ballast hum Directional light sources Do not contain mercury Do not get hot Replace less frequently **Phillips L prize, Definity A19 and Sylvania 12, watt found to be best LED light bulbs Source: http://led-light-bulbs-review.toptenreviews.com
Use of LED lighting as a diagnostic tool to assess low vision “Luminance in Acuity and Reading Performance of Low Vision Patients” D. Fletcher, R. Schuchard, L.Renninger, Source Envision 2012 and ARVO 2013 Results: 140 patients with MD saw an average of 2 blocks increase on MNReasd using white LED light for high illumination (2070 Lux) 1 in 6 patients had ring scotoma; there was an average of 4 blocks of increase “All patients and particularly those with ring scotomas should have trials with very bright illumination in their rehabilitation program.”
Home Safety and Lighting Visually impaired individual are generally not aware of the importance of lighting in the home (Harper, Doorduyn, Reeves, & Slater 1999: Schuchard, Naseer, and de Csatro, 1999).
Low Vision Lighting Assessment Can consist of both ambient and task lighting Primarily task lighting assessments are the focus for the low vision patient for near vision tasks-reading writing, meal prep, clothing identification Education plays a key role Demo of lighting and participation with low vision patient is essential for success Use both objective measures (light meter) and subjective responses to base determination of lighting recommendations
Objective Measurements Measurement of objective low vision areas assists the low vision patient in acceptance of the lighting recommendations. The following are common improvements demonstrated after lighting assessment (besides light levels and glare); MN Read (reading rate) Accuracy (number of errors) Acuity (measurement of size print able to read) Eye comfort (minimizing glare) Reading duration (eye fatigue)
Home Lighting Assessment HELA-Home Environment Lighting Assessment developed by Monica S. Permutter, OTD, OTR/L, SCLV (very comprehensive) Other lighting assessment available: HOPE, Housing Enables, and CHIEF
Increase visibility of the task and environment Enhance visual components of tasks Augment performance with other sensory system input-tactile, olfactory, auditory
Ensure lighting is optimal for task performance Use contrast to increase visibility of key objects and landmarks Minimize background pattern Maximize and enlarge Organize
Use layered lighting=work spaces, laundry, crafts, kitchen, shop Ambient=general room light Task=brighter illumination for specific activity
Always behind person to read, eliminate shadows on surface, as close to task as person can tolerate, facing hand when writing to eliminate shadow Two ways to increase task illumination 1. move light closer to surface 2. get a stronger light
Flashlight/fixture near bed-touch lamp Nightlight/path light with rope light Additional switches Motion or sound activated light Head lamp to mount on head Under counter lights, tap on light for closets
Light colored plate on dark placemat Milk in dark cup/coffee in white cup Telephone stick on numbers-usually can see white on black best, computer keyboard-add stick on letters or purchase new keyboard with different contrast Two sided cutting board-white for carrots, black for potatoes Measuring cups-dark/light to measure contrast ingredients Use contrast to increase environment-tack mat at bottom of stairs-most falls occur on last step, contrast tape on light switch Thresholds that are raised-add contrast electrical tape-yellow, red, black
Use solid color on background and support surfaces Eliminate clutter When unable to eliminate pattern, increase contrast of key features-place eating utensils on solid napkin, place red tape around sharp knife handles
Use hands free magnification: magnifying mirrors, chest magnifier, Big eye magnifier Enlarge-large print address book, spice organizer with large letters Enhance visual components/augment with other sensory input-liquid leveler with auditory output, use various material to mark features of object to increase visibility-contrast touch dots on microwave
Labs Macular Degeneration Write Grocery list Standard pen and paper-10 items Use PBS (Print-Bold-Space) on dark lines paper Read both with vision simulators Have classmate read your standard list with simulator- your classmate will go to the store for you-what do you think you will get!! Move to goose neck lamp and try again-any difference
Lab Diabetic Retinopathy View newspaper and grocery ads View with simulators-what is the difference? Try reading with task lighting
Lab Glaucoma Look up number in phone book Dial on your cell phone Any errors?? Improve lighting-any easier?
Lab-Lighting Lighting Read with any vision simulator standard print, then 20 point print without extra light and then with increased LED, Halogen and incandescent goose neck lighting? Which is easier? What can you tell your client? Try the Vision Edge clip on light (White and Green LED lights) and try reading in darker area of the room. What is this like?
Lab-Contrast With any vision simulator pour water into clear glass. Any errors? Pour dark ingredient into light cup and light ingredient into dark cup. Use liquid leveler to pour with vision totally occluded. Trial of different colored plates on different colors of placemats with vision simulators. Which colors are easier? How can you mark utensils for easier recognition by low vision client?
Lab With any simulator Try to identify classmate without hearing their voice. Walk into hallway and attempt to identify signage-bathroom, vending machines, stairs, numbers to rooms.
Acuity-near & intermediate Contrast Sensitivity Environmental Adaptations ADLs and IADLs adaptations Low Tech equipment recommendations Refer to appropriate specialist-LV OT
Educate patient for vision diagnosis Identify scotomas and locate PRL Train with eccentric viewing techniques-near and intermediate Select with approval of Optometrist or Ophthalmologist best diopter of magnifier- hand held, stand, or electronic High Tech options for LV client
Train with use of magnifier-requires skill to be successful for spot reading or continuous text Environmental changes to include lighting, increase contrast for safety, tactile guides Bioptic, telescopic training Sighted Guide techniques-indoor CVA-hemianopsia for visual field loss or visual neglect
Low Vision Occupational Therapy Evaluation and Intervention with Older Adults, Revised Edition (Self-Paced Clinical Course) edited by Mary Warren, PhD, OTR/L, SCLV FAOTA Order # 3025, AOTA Members: $370, Nonmembers $470, 20 CEUs Low vision In Older Adults: Foundations for Rehabilitation, 2 nd Edition, by Roy Gordon Cole, OD, FAAO, Yu-Pen Hsu, EdD, OT, SCLV, and Gordon Rovins, MS, CEAC (On-line Course) Order #OL37, AOTA members $265, Nonmembers $345. Graduate Certificate in Low Vision Rehabilitation, University of Alabama at Birmingham, Mary Warren PhD, OTR/L, SCLV, FAOTA Associate Professor, Occupational Therapy: firstname.lastname@example.org@uab.edu (5 semester course on line)
Lighthouse International-accessibility; www.lighthouse.org/accessibility www.lighthouse.org/accessibility Mdsupport-resource link; http://mdsupport.org/resources.html American Foundation for the Blind-senior site; http://www.afb.org/seniorsitehome.asp http://www.afb.org/seniorsitehome.asp Foundation Fighting Blindness www.blindness.org Glaucoma Foundation www.glaucoma-foundation.org/info Macular Degeneration International www.maculardegeneration.org
American Printing House for the Blind www.aph.org/index.html www.aph.org/index.html Ann Morris Enterprises, Inc. www.annmorries.com www.annmorries.com Carolyn’s Low Vision Products http://www.carolynscatagog.com http://www.carolynscatagog.com Dazor Lighting Specialists http://www.dazor.com/ http://www.dazor.com/ Independent Living Aids, Inc. www.independentliving.com www.independentliving.com NoIR Medical Technologies www.Noir-medical.com www.Noir-medical.com
Low Vision CEU programs available upon request. Please contact me for proposal for your company or group.