II. Epidemiology

  1. Incidence of Low Vision increases with age
    1. Affects 3-4% of patients over age 40 years old
    2. Affects 7% of patients over age 65 years old
    3. Affects 25% of patients over age 80 years old

III. Symptoms: Normal changes related to aging

  1. Presbyopia
  2. Decreased contrast sensitivity
  3. Decreased dark-light adaptation
  4. Delayed glare recovery

IV. Symptoms: Abnormal

V. Causes: Common (over age 40 years)

  1. See Acute Vision Loss
  2. Age-Related Macular Degeneration (54% of all blindness in U.S.)
  3. Cataracts (most common cause of blindness worldwide)
  4. Glaucoma
  5. Diabetic Retinopathy (present in up to 10% of diabetes patients at time of initial diagnosis)

VII. Interpretation

  1. Low Vision
    1. Central Vision 20/70 in best seeing eye with best correction OR
    2. Total Visual Field loss of 140 degrees
  2. Mild Vision Loss
    1. Vision 20/30 to 20/70
    2. Visual Field <30 degrees
  3. Moderate Vision Loss
    1. Vision 20/80 to 20/160
  4. Severe Vision Loss (legal blindness)
    1. Vision 20/200 to 20/400
    2. Visual Field <20 degrees
  5. Profound Vision Loss
    1. Vision 20/500 to 20/1000
  6. Near Total Blindness
    1. Can detect hand motions
    2. Light Perception intact
  7. Total Blindness
    1. No light Perception

VIII. Evaluation: Indications for eye care specialist referral

  1. Acute Vision Loss (emergent)
  2. Uncorrected Vision <20/50 or
  3. One line difference (on Snellen Chart) between eyes

IX. Management: Vision Enhancing Devices

  1. See specific conditions
  2. Magnification Devices for reading
    1. High powered prismatic spectacles
    2. Handheld magnifier
    3. Stand magnifier
  3. Magnification Devices for more intricate activities
    1. Telemicroscopes (spectacle-mounted telescopes)
    2. Telescopes
  4. Adjunctive Vision devices
    1. Filters to enhance contrast
    2. Filters to reduce glare
  5. Electronic vision Assistive Devices
    1. Video magnifiers
    2. Computer voice synthesizers to read text
  6. Other options
    1. Large print books
    2. Audiobooks

X. Prevention

  1. See Preventive Eye Examination
  2. Low Vision may be preventable in up to 40-50% with periodic Vision Screening
  3. See Home Modifications for Vision Impaired Patients
  4. General measures
    1. Tobacco Cessation
    2. Sunglasses (limit ultraviolet light exposure)
    3. Control comorbid conditions
      1. Diabetes Mellitus
      2. Hypertension
      3. Hyperlipidemia

XI. Complications

  1. Major Depression
  2. Social withdrawal and isolation
  3. Loss of independence
  4. Increased Fall Risk
  5. Hallucinations
  6. Higher risk of older adults being institutionalized
  7. Higher risk of medication errrors
  8. Increased all cause mortality

XII. Resources

  1. American Council of the Blind
    1. http://www.acb.org
  2. American Foundation for the Blind
    1. http://www.afb.org
  3. Jewish Guild for the Blind
    1. http://www.jgb.org
  4. Lighthouse International
    1. http://www.lighthouse.org
  5. National Federation of the Blind
    1. http://www.nfb.org
  6. Prevent Blindness America
    1. http://www.preventblindness.org
  7. VisionAWARE
    1. http://www.visionaware.org

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Low Vision (C0042798)

Definition (NCI) Reduced ability to perceive visual stimuli.
Definition (MSH) Vision considered to be inferior to normal vision as represented by accepted standards of acuity, field of vision, or motility. Low vision generally refers to visual disorders that are caused by diseases that cannot be corrected by refraction (e.g., MACULAR DEGENERATION; RETINITIS PIGMENTOSA; DIABETIC RETINOPATHY, etc.).
Concepts Disease or Syndrome (T047)
MSH D015354
SnomedCT 155146008, 193698004, 246635007, 40031005
English Subnormal Vision, Vision, Low, Vision, Subnormal, Reduced vision, Decreased vision, Poor vision, Vision dim, Vision decreased, Diminished Vision, Vision, Diminished, Reduced Vision, Vision, Reduced, Vision, Low [Disease/Finding], dim vision, Decreased;vision, Poor;vision, dimming vision, Low vision, Low Vision, Darkened vision, Dim vision, Dim vision (disorder), poor; vision, vision; poor, Decreased vision, NOS, Low vision, NOS, decreased vision, poor vision
Dutch gezichtsvermogen verminderd, slecht gezichtsvermogen, gezichtsvermogen zwak, gezichtsvermogen; slecht, slecht; gezichtsvermogen, Gezichtsvermogen, verminderd, Verminderde visus, Visus, verminderde, Visusdaling
French Mauvaise vision, Vision diminuée, Vision obscurcie
German schlecht sehen, Sehvermoegen vermindert, Sehen schwach
Italian Visione ridotta, Vista scarsa, Visione indistinta
Portuguese Visão diminuída, Visão deficiente, Visão obscura, Baixa Visão, Visão Reduzida, Visão Subnormal
Spanish Visión escasa, Visión disminuida, Visión oscurecida, poca visión, visión disminuida, visión débil (trastorno), visión débil, Baja Visión, Visión Reducida, Visión Subnormal
Japanese 視力低下, 視力不良, シリョクフリョウ, シリョクテイカ, ぼんやりとした視界, ボンヤリトシタシカイ
Czech Slabozrakost, Snížený zrak, Nejasné vidění
Swedish Synnedsättning
Polish Widzenie osłabione
Hungarian Látás, gyenge, Látáscsökkenés, Rossz látás

Ontology: Blind Vision (C0456909)

Definition (NCI) The lack of vision. It is caused by neurological or physiological factors.
Definition (MSH) The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.
Definition (CSP) inability to see or the loss or absence of perception of visual stimuli; condition may be the result of eye, optic nerve, optic chiasm or brain diseases effecting the visual pathways or occipital lobe.
Concepts Finding (T033)
MSH D001766 , D015354, D014786
SnomedCT 40031005, 139548004, 277675000, 397540003
LNC LA17710-7
English Blindness, BLINDNESS, Cannot see, Loss of vision, Unable to see, UTS - Unable to see, Blind Vision, Blindness [Disease/Finding], blindness, blind, blind vision, Blindness NOS, Blindness (finding), Blind (finding), Blind, Blindness, NOS
French CECITE, Cécité SAI, Aveugle, Déficience de la vision, Déficience visuelle, Cécité, Vision basse, Non-voyance, Vision diminuée, Vision faible, Vision réduite
Portuguese CEGUEIRA, Cegueira NE, Cego, Cegueira
Spanish CEGUERA, Ceguera NEOM, Ciego, ciego, ciego (hallazgo), ceguera (trastorno), ceguera, Ceguera
German BLINDHEIT, Blindheit NNB, blind, Blindheit, Sehverlust, Sehschwäche, Sehvermögen, herabgesetztes, Sehvermögen, vermindertes
Dutch blindheid NAO, blind, Blindheid, laag; visus, blindheid, Amaurose
Italian Cieco, Cecità NAS, Visione ridotta, Ipovisione, Cecità
Japanese 失明NOS, シツメイ, シツメイNOS, 視覚消失症, , 亜正常視覚, 黒内障, 失明, 低視力, 低視覚, ロービジョン, 視覚-亜正常, 視覚-低
Swedish Blindhet
Czech slabozrakost, zrak subnormální, slepota, vidění snížené, Nevidomý, Slepota, Nevidomost NOS
Finnish Sokeus, Heikentynyt näkö
Polish Ślepota, Obniżenie jakości widzenia, Wzrok słaby, Wzrok subnormalny, Widzenie obniżone
Hungarian Vakság, Amaurosis k.m.n., Vak
Norwegian Redusert synsevne, Blindhet, Synshemning, Svekket syn, Nedsatt syn, Synssvekkelse, Svakt syn, Synsnedsettelse

Ontology: Optical low vision aid (C0730385)

Concepts Medical Device (T074)
SnomedCT 313024004
English Optical low vision aid, Optical low vision aid (physical object)
Spanish lentes para visión escasa (objeto físico), lentes para visión escasa