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Decreased Visual Acuity
Aka: Decreased Visual Acuity, Visual Impairment, Low Vision, Vision Loss, Optical Low Vision Aid- See Also
- Epidemiology
- Incidence of Low Vision increases with age
- Prevalence: 3.3 million in U.S. over age 40 years (3-4%)
- Age over 80 years: Accounts for 70% of blindness
- Incidence of Low Vision increases with age
- Symptoms: Normal changes related to aging
- Presbyopia
- Decreased contrast sensitivity
- Decreased dark-light adaptation
- Delayed glare recovery
- Symptoms: Abnormal
- See Acute Vision Loss
- Loss of central vision
- Loss of peripheral vision
- Generalized loss of vision
- Causes: Common (over age 40 years)
- See Acute Vision Loss
- Age-Related Macular Degeneration (54% of all blindness in U.S.)
- Cataracts (most common cause of blindness worldwide)
- Glaucoma
- Diabetic Retinopathy (present in up to 10% of diabetes patients at time of initial diagnosis)
- Exam
- See Visual Acquity
- Intraocular Pressure
- Amsler Grid
- Funduscopic Exam
- Interpretation
- Mild Vision Loss
- Vision 20/30 to 20/70
- Visual field <30 degrees
- Moderate Vision Loss
- Vision 20/80 to 20/160
- Severe Vision Loss
- Vision 20/200 to 20/400
- Visual field <20 degrees
- Profound Vision Loss
- Vision 20/500 to 20/1000
- Near Total Blindness
- Can detect hand motions
- Light perception intact
- Total Blindness
- No light perception
- Mild Vision Loss
- Evaluation: Indications for eye care specialist referral
- Acute Vision Loss (emergent)
- Uncorrected vision <20/50 or
- One line difference (on Snellen Chart) between eyes
- Management: Vision Enhancing Devices
- See specific conditions
- Magnification Devices for reading
- High powered prismatic spectacles
- Handheld magnifier
- Stand magnifier
- Magnification Devices for more intricate activities
- Telemicroscopes (spectacle-mounted telescopes)
- Telescopes
- Adjunctive vision devices
- Filters to enhance contrast
- Filters to reduce glare
- Electronic vision Assistive Devices
- Video magnifiers
- Computer voice synthesizers to read text
- Other options
- Large print books
- Audiobooks
- Prevention
- See Preventive Eye Examination
- Low Vision may be preventable in up to 40-50% with periodic Vision Screening
- See Home Modifications for Vision Impaired Patients
- General measures
- Tobacco Cessation
- Sunglasses (limit ultraviolet light exposure)
- Control comorbid conditions
- Complications
- Depression
- Social withdrawal and isolation
- Increased fall risk
- Hallucinations
- Higher risk of older adults being institutionalized
- Higher risk of medication errrors
- Resources
- American Council of the Blind
- American Foundation for the Blind
- Jewish Guild for the Blind
- Lighthouse International
- National Federation of the Blind
- Prevent Blindness America
- VisionAWARE
- References