• Like
Visual impairment 2
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

Visual impairment 2

  • 202 views
Published

 

Published in Health & Medicine
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
202
On SlideShare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
14
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Visual ImpairmentVisual ImpairmentMedical and PsychosocialMedical and PsychosocialAspects of DisabilityAspects of Disability
  • 2. IntroductionIntroduction• Vision impairment affects a significantVision impairment affects a significantproportion of middle-aged and older Americansproportion of middle-aged and older Americans– 1 in 6 adults (17%), age 45 and older, representing1 in 6 adults (17%), age 45 and older, representing13.5 million Americans, reports some form of vision13.5 million Americans, reports some form of visionimpairment even when wearing glasses or contactimpairment even when wearing glasses or contactlenseslenses• The prevalence of visual impairments increaseThe prevalence of visual impairments increasewith agewith age– 15% of people 45-6415% of people 45-64– 17% of people 65-7417% of people 65-74– 26% of people 75 and older26% of people 75 and older
  • 3. Factors Affecting Visual FunctionFactors Affecting Visual Functionand Their Treatmentand Their Treatment• Visual Acuity - ability to see "detail"Visual Acuity - ability to see "detail"– Measured using testing distance/letter sizeMeasured using testing distance/letter size– Normal is 20/20Normal is 20/20– Limitation on acuity level is generally determined by the spacingLimitation on acuity level is generally determined by the spacingof the conesof the cones– Treatment:  glasses or some form of magnificationTreatment:  glasses or some form of magnification• Visual Field - a persons peripheral visionVisual Field - a persons peripheral vision– Scotoma - loss of vision in an areaScotoma - loss of vision in an area• ContrastContrast• Lighting and GlareLighting and Glare– Often, too much light can be as detrimental as not enoughOften, too much light can be as detrimental as not enough
  • 4. Definition of Legal BlindnessDefinition of Legal Blindness• WHO Definition:WHO Definition: Best-corrected visual acuityBest-corrected visual acuityof less than 6/120 (<20/400) in the better-seeingof less than 6/120 (<20/400) in the better-seeingeye.eye.• US Definition:US Definition: Best-corrected visual acuity ofBest-corrected visual acuity of6/60 or worse (6/60 or worse (<<20/200) in the better-seeing20/200) in the better-seeingeye.eye.OROR• Peripheral visual field is restricted to 20° or lessPeripheral visual field is restricted to 20° or lessin the widest meridian of the better eyein the widest meridian of the better eye• (US Definition of Low Vision:(US Definition of Low Vision: best-corrected visual acuity of 6/12 (<20/40)best-corrected visual acuity of 6/12 (<20/40)in better-seeing eye.)in better-seeing eye.)
  • 5. StatisticsStatistics• In 2000 there were 937,000 blindIn 2000 there were 937,000 blindAmericans older than 40 (0.78%)Americans older than 40 (0.78%)• 2,400,000 with low vision (1.98%)2,400,000 with low vision (1.98%)• Thus, there were 3.3 million AmericansThus, there were 3.3 million Americansaged 40 or more with a visual impairmentaged 40 or more with a visual impairmentin 2000in 2000The Eye Diseases Prevalence Research Group (2004). Causes and prevalence of visualThe Eye Diseases Prevalence Research Group (2004). Causes and prevalence of visualimpairment among adults in the United States.impairment among adults in the United States. Archives of Ophthalmology, 122Archives of Ophthalmology, 122, 477-485., 477-485.
  • 6. The Eye Diseases Prevalence Research Group, Arch Ophthalmol 2004;122:477-485.AMD=age-related macular degeneration, DR=diabetic retinopathyCauses of blindness (best-corrected visual acuity <6/60 [<20/200] in the better-seeing eye) by race/ethnicity
  • 7. .The Eye Diseases Prevalence Research Group, Arch Ophthalmol 2004;122:477-485.AMD=age-related macular degeneration, DR=diabetic retinopathyCauses of low vision (best-corrected visual acuity <6/12 [<20/40] in the better-seeingeye, excluding those who were categorized as being blind by the US definition) byrace/ethnicity
  • 8. Prevalence of Blindness by AgePrevalence of Blindness by Ageand Race (US)and Race (US)WhiteWhite BlackBlack HispanicHispanic40-4940-49 0.120.12 0.180.18 0.050.0550-5450-54 0.100.10 0.340.34 0.100.1055-5955-59 0.110.11 0.520.52 0.160.1660-6460-64 0.150.15 0.810.81 0.260.2665-6965-69 0.230.23 1.251.25 0.410.4170-7470-74 0.430.43 1.931.93 0.640.6475-7975-79 0.930.93 2.962.96 0.990.99>>8080 6.826.82 6.856.85 2.422.42
  • 9. CataractsCataracts• A cataract is opacity or clouding ofA cataract is opacity or clouding ofthe lens that may develop as athe lens that may develop as aresult of aging, trauma, hereditaryresult of aging, trauma, hereditaryfactors, birth defects, or diabetesfactors, birth defects, or diabetes• Cataracts are a normal part of agingCataracts are a normal part of aging– Approximately 50% of AmericansApproximately 50% of Americansbetween 65 and 74 and 70% overbetween 65 and 74 and 70% overage 75 have cataractsage 75 have cataracts• Prevalence factorsPrevalence factors– Caucasians are three times as likelyCaucasians are three times as likelyas African-Americans to developas African-Americans to developcataractscataracts– Smokers have a 60% increaseSmokers have a 60% increase– Those taking medication for gout areThose taking medication for gout aretwice as likely to develop cataractstwice as likely to develop cataracts• The greater the progression of theThe greater the progression of thecataract, the greater the visualcataract, the greater the visualimpairment from the effects of glare,impairment from the effects of glare,loss of contrast, and decreasedloss of contrast, and decreasedvisual acuityvisual acuity• Normally, cataracts are successfullyNormally, cataracts are successfullytreated with surgerytreated with surgery• Assuming no complications, thereAssuming no complications, thereshould be no vocational implicationsshould be no vocational implicationsfollowing cataract surgeryfollowing cataract surgeryNo cataract cataract
  • 10. Corneal DiseaseCorneal Disease• The cornea is a structure that is prone to dystrophies, deposition,The cornea is a structure that is prone to dystrophies, deposition,noninflammatory progressive thinning (keratoconus), infection, viralnoninflammatory progressive thinning (keratoconus), infection, viraldiseases, and traumadiseases, and trauma• Interference with corneal integrity can result in a blurred or distorted imageInterference with corneal integrity can result in a blurred or distorted imageon the retinaon the retina– May experience severe glare, cloudy vision, and reduced acuityMay experience severe glare, cloudy vision, and reduced acuity• TreatmentTreatment– Keratoplasty is the primary method of restoring vision for an individual with aKeratoplasty is the primary method of restoring vision for an individual with adiseased, irregular, or scarred cornea - procedure involves transplanting adiseased, irregular, or scarred cornea - procedure involves transplanting ahealthy cornea from a compatible donorhealthy cornea from a compatible donor– Recently, lasers have been used to treat some corneal problemsRecently, lasers have been used to treat some corneal problems• Vocational ImplicationsVocational Implications– Vocational goals will be dependent on the degree to which the retinal image isVocational goals will be dependent on the degree to which the retinal image iscompromisedcompromised
  • 11. Macular DegenerationMacular Degeneration• Macular degeneration is caused byMacular degeneration is caused bydegenerative changes to the macular areadegenerative changes to the macular areaof the retina that result in atrophy,of the retina that result in atrophy,hemorrhage, exudates, fibrovascular scars,hemorrhage, exudates, fibrovascular scars,or cyst formationsor cyst formations• Risk factorsRisk factors– CaucasianCaucasian– Family historyFamily history– High blood pressure or a history ofHigh blood pressure or a history ofhypertensionhypertension– Light iris colorLight iris color– SmokingSmoking• Functional PresentationFunctional Presentation– Visually manifested as distortions, a decreaseVisually manifested as distortions, a decreasein the visual acuity, a decrease in colorin the visual acuity, a decrease in colorrecognition, a loss of contrast, or an absoluterecognition, a loss of contrast, or an absoluteor relative area of no vision (scotoma)or relative area of no vision (scotoma)– Reading may become increasingly difficultReading may become increasingly difficultand driving may have to be discontinuedand driving may have to be discontinued
  • 12. Macular DegenerationMacular Degeneration• TreatmentTreatment– Laser treatment can sometimes be used to slow the progression ofLaser treatment can sometimes be used to slow the progression ofthe diseasethe disease– Other treatments that have been investigated (but not yetOther treatments that have been investigated (but not yetestablished) include the use of radiation, laser treatment of drusenestablished) include the use of radiation, laser treatment of drusen(small globular pathological growths formed on optic papilla or on(small globular pathological growths formed on optic papilla or onDescemets membrane), photodynamic therapy, submacularDescemets membrane), photodynamic therapy, submacularsurgery, retinal cell transplantation, and the use of vascularsurgery, retinal cell transplantation, and the use of vascularendothelial growth factorendothelial growth factor• Vocational ImplicationsVocational Implications– DrivingDriving– Vision rehabilitation program may be needed before being able toVision rehabilitation program may be needed before being able toreturn to workreturn to work• Accommodations/Assistive TechnologyAccommodations/Assistive Technology– Lenses and magnification devicesLenses and magnification devices– Talking booksTalking books– Bold, felt-tip pensBold, felt-tip pens– Talking clocks (and other talking devices and appliances)Talking clocks (and other talking devices and appliances)
  • 13. Diabetic RetinopathyDiabetic Retinopathy• Diabetes accounts for about 5,000Diabetes accounts for about 5,000new cases of blindness each year andnew cases of blindness each year andpeople with diabetes have a 25 timespeople with diabetes have a 25 timesgreater risk for blindness than thegreater risk for blindness than thegeneral populationgeneral population– Approximately 40% of people withApproximately 40% of people withdiabetes have diabetic retinopathydiabetes have diabetic retinopathy• Functional PresentationFunctional Presentation– Fluctuating or severely decreasedFluctuating or severely decreasedvisual acuityvisual acuity– Problems due to glare, reducedProblems due to glare, reducedcontrast sensitivity, and various typescontrast sensitivity, and various typesof visual field problemsof visual field problems– May have transient episodes ofMay have transient episodes ofdiplopiadiplopia
  • 14. Diabetic RetinopathyDiabetic Retinopathy• Vocational ImplicationsVocational Implications– Rehabilitation considerations must include notRehabilitation considerations must include notonly vision but also the effect of diabetes ononly vision but also the effect of diabetes onother systemsother systems• Accommodations/Assistive TechnologyAccommodations/Assistive Technology– Low-vision devicesLow-vision devices– Prisms to correct transitory diplopiaPrisms to correct transitory diplopia
  • 15. GlaucomaGlaucoma• If left untreated, results in the destruction of theIf left untreated, results in the destruction of theperipheral retinaperipheral retina• Basically three types of glaucomaBasically three types of glaucoma– Chronic open-angle glaucoma:  elevated pressureChronic open-angle glaucoma:  elevated pressureover time eventually affects the optic nerve and visualover time eventually affects the optic nerve and visualfieldfield– Acute (closed-angle) glaucoma:  rapid increase orAcute (closed-angle) glaucoma:  rapid increase orspiking of the intraocular pressure that may bespiking of the intraocular pressure that may beaccompanied by intense pain and even nausea oraccompanied by intense pain and even nausea orvomitingvomiting– Low-tension glaucoma:  may be caused by aLow-tension glaucoma:  may be caused by adecrease in blood flow to the optic nervedecrease in blood flow to the optic nerve• Over a period of time, especially if leftOver a period of time, especially if leftuntreated, irreversible optic nerve and visualuntreated, irreversible optic nerve and visualfield damage will occur, impairing night vision,field damage will occur, impairing night vision,visual acuity, mobility, and reading skillsvisual acuity, mobility, and reading skills
  • 16. GlaucomaGlaucoma• TreatmentTreatment– Medications that decrease production of aqueous humor or facilitateMedications that decrease production of aqueous humor or facilitateoutflow of fluidoutflow of fluid– Laser surgery to create drainage holesLaser surgery to create drainage holes– Other surgery procedures to assist with drainageOther surgery procedures to assist with drainage• Vocational ImplicationsVocational Implications– Progressive loss of vision may result in difficulty in performing ones jobProgressive loss of vision may result in difficulty in performing ones job• Accommodations/Assistive TechnologyAccommodations/Assistive Technology– Low-vision devices, including spectacles, hand and stand magnifiers,Low-vision devices, including spectacles, hand and stand magnifiers,closed circuit TV, and lightingclosed circuit TV, and lighting– Absorptive lenses enhance the apparent brightness of the scene andAbsorptive lenses enhance the apparent brightness of the scene andoften aid in mobilityoften aid in mobility– Modifications in the work space may be required, with high technology,Modifications in the work space may be required, with high technology,including voice-output devicesincluding voice-output devices
  • 17. AlbinismAlbinism• Albinism is a trait that is inherited through autosomal recessive orAlbinism is a trait that is inherited through autosomal recessive orsex-linked transmission and results in characteristics that affect thesex-linked transmission and results in characteristics that affect thepigmentation of the skin and hair as well as the iris and retinapigmentation of the skin and hair as well as the iris and retina• Persons with albinism have a decrease in visual acuity due toPersons with albinism have a decrease in visual acuity due tomacular aplasiamacular aplasia• Treatment consists of corrective spectacle lenses as well asTreatment consists of corrective spectacle lenses as well asabsorptive lenses to reduce light sensitivityabsorptive lenses to reduce light sensitivity• Vocational ImplicationsVocational Implications– Similar to other types of visual impairmentsSimilar to other types of visual impairments– Need to pay attention to exposure to sunlightNeed to pay attention to exposure to sunlight• Accommodations/Assistive TechnologyAccommodations/Assistive Technology– Low-vision devices, including strong microscopic reading lenses,Low-vision devices, including strong microscopic reading lenses,magnifiers, absorptive lenses, and telescopic lensesmagnifiers, absorptive lenses, and telescopic lenses
  • 18. Retinitis PigmentosaRetinitis Pigmentosa• A progressive eye disease that affectsA progressive eye disease that affectsthe pigmentary layer of the retina, andthe pigmentary layer of the retina, andmost commonly affects the peripherymost commonly affects the peripheryor midperiphery of the retinaor midperiphery of the retina• Most common cause of inheritedMost common cause of inheritedblindnessblindness• In addition, 30% of people with RPIn addition, 30% of people with RPreport some degree of hearing lossreport some degree of hearing loss• Functional PresentationFunctional Presentation– Night vision and peripheral vision goNight vision and peripheral vision gohand in hand - the more advanced thehand in hand - the more advanced theRP, the greater loss of peripheralRP, the greater loss of peripheralvision and the more difficult to travelvision and the more difficult to travel– Reading becomes more and moreReading becomes more and moredifficult as the visual field becomesdifficult as the visual field becomessmallsmall– Glare or light sensitivity is frequentlyGlare or light sensitivity is frequentlyassociated with RPassociated with RP
  • 19. Retinitis PigmentosaRetinitis Pigmentosa• TreatmentTreatment– At present, no medical or surgical treatments are known to stop orAt present, no medical or surgical treatments are known to stop ordecrease the progression of RPdecrease the progression of RP– Refractive corrections are necessary, along with absorptive lensesRefractive corrections are necessary, along with absorptive lensesto cut down the glare or light sensitivityto cut down the glare or light sensitivity– Contrast-enhancing lenses may be beneficial in enhancingContrast-enhancing lenses may be beneficial in enhancingperformance and reducing adaptation times between outdoors andperformance and reducing adaptation times between outdoors andindoorsindoors• Vocational ImplicationsVocational Implications– Individuals with severe progressive visual field loss should notIndividuals with severe progressive visual field loss should notcontemplate occupations that will necessitate drivingcontemplate occupations that will necessitate driving• Accommodations/Assistive TechnologyAccommodations/Assistive Technology– Closed-circuit TV to enable the person to control the brightness andClosed-circuit TV to enable the person to control the brightness andcontrast of the image viewedcontrast of the image viewed– Prism lenses to increase the awareness of the peripheryPrism lenses to increase the awareness of the periphery– The Nightsope might be able to be used for mobility under dimThe Nightsope might be able to be used for mobility under dimilluminationillumination– Mobility devices, such as a traveling cane, special laser cane,Mobility devices, such as a traveling cane, special laser cane,sensory device, or Seeing Eye dogsensory device, or Seeing Eye dog
  • 20. Peripheral Visual Field LossPeripheral Visual Field Lossfrom Strokes or Tumorsfrom Strokes or Tumors• A person who has a stroke or tumor can be left with aA person who has a stroke or tumor can be left with aresultant visual field lossresultant visual field loss• In addition, can affect perception of visual form, color,In addition, can affect perception of visual form, color,object meaning, recognition, and attentionobject meaning, recognition, and attention• May also be disorders of the visual system such asMay also be disorders of the visual system such ashallucinationshallucinations• Vocational Implications - drivingVocational Implications - driving• Accommodations/Assistive TechnologyAccommodations/Assistive Technology– Prisms to enhance spatial awarenessPrisms to enhance spatial awareness– Mirrors to facilitate peripheral field awarenessMirrors to facilitate peripheral field awareness– Low-vision devicesLow-vision devices
  • 21. General Vocational ImplicationsGeneral Vocational Implications• Transportation issues need to beTransportation issues need to beconsideredconsidered• Safety issues need to be consideredSafety issues need to be considered
  • 22. ResourcesResources• The National Society to Prevent Blindness (www.eyeinfo.org/national.html)The National Society to Prevent Blindness (www.eyeinfo.org/national.html)• Prevent Blindness America (http://www.preventblindness.org/)Prevent Blindness America (http://www.preventblindness.org/)• Prevent Blindness Florida (www.preventblindness.org/florida/)Prevent Blindness Florida (www.preventblindness.org/florida/)• American Academy of Opthamology (http://www.aao.org/)American Academy of Opthamology (http://www.aao.org/)• Glaucoma Research Foundation (http://www.glaucoma.org/)Glaucoma Research Foundation (http://www.glaucoma.org/)• Lighthouse International (http://www.lighthouse.org/)Lighthouse International (http://www.lighthouse.org/)• AMD Alliance International (http://www.amdalliance.org/)AMD Alliance International (http://www.amdalliance.org/)• National Eye Institute (http://www.nei.nih.gov/)National Eye Institute (http://www.nei.nih.gov/)• National RP Foundation (www.rpsa.org.za/training.htm)National RP Foundation (www.rpsa.org.za/training.htm)• Research to Prevent Blindness (http://www.rpbusa.org/)Research to Prevent Blindness (http://www.rpbusa.org/)• The Rehabilitation Research and Training Center on Blindness and LowThe Rehabilitation Research and Training Center on Blindness and LowVision (http://www.blind.msstate.edu/)Vision (http://www.blind.msstate.edu/)• Florida Division of Blind Services (www.state.fl.us/dbs/index.shtml)Florida Division of Blind Services (www.state.fl.us/dbs/index.shtml)• JANs webpage (www.jan.wvu.edu/media/sight.html)JANs webpage (www.jan.wvu.edu/media/sight.html)