Fall rates increase with increasing age and account for 87% of injury hospitalizations in 85+ year olds. One major cause of falls is visual impairment.
People with visual impairments are more than twice as likely to fall as people without visual impairments. They also have three times the risk of depression and the risk of hip fractures increases eight fold.
There are both intrinsic and extrinsic factors that contribute to vision related falls:
Intrinsic Factors Contributing to Vision Related Falls:
Reduced depth perception— Older people who have decreased vision in one eye have more difficulty judging distances. This can make it difficult judging the distance from hazardous obstacles.
Reduced contrast sensitivity— Older adults who have visual impairments may have difficulty seeing changes in surfaces as they cannot make out a solid edge of contrast. Reduced contrast sensitivity can make it difficult to detect obstacles or clutter and make make curbs nearly invisible.
Reduced visual field— Whereas some eye diseases such as Glaucoma may result in poorer peripheral vision, other eye diseases like Diabetic Retinopathy or Age-related Macular Degeneration (AMD) may cause blind spots in the central field, or throughout the visual field. Objects that are not seen cannot be avoided, so reduced visual fields are a common cause of falls, especially when coupled with environmental hazards.
Age Related Vision Loss—. The most common pathological eye conditions which affect the elderly include cataracts, age-related macular degeneration, diabetic retinopathy, and glaucoma. Cataracts often develop slowly and occur when the normally clear lens becomes cloudy. Cataracts often result in blurred vision, sensitivity to bright lights and glare, and difficulty seeing at night.
Age Related Normal Vision— Aging is often accompanied by normal changes in the eyes that can increase the risk of falls. These normal age-related changes in the eye occur after the age of 40. These changes make it difficult to change the focus of the eye between near and far objects.
Postural sway linked with vision motion- Any deficit or delay in the processing of visual information (moving or still objects) may increase the risk of postural instability and falls.
Extrinsic Factors Contributing to Vision Related Falls::
Environment- poor lighting, slippery surfaces, clutter on the floor, rugs, pets and changes in floor surface are all examples of environmental factors that can lead to increased falls in vision impaired people.
Medication- some medication can cause disturbances to vision in the elderly. It is important to optimize medication doses to avoid such possible side effects.
Glasses- it is very important to have glasses with appropriate prescriptions. Inappropriate glasses can be a falls risk as it leads to inappropriate stepping and gait adaptations. Multifocal glasses can add to this risk by impairing contrast sensitivity, depth perception, and ability to negotiate obstacles. Sometimes providing new glasses can increase falls; People may need time to adapt to their new glasses and for some others they may adopt more risk-taking activities (thus increasing the exposure to falls) after their vision improvement with new glasses.
What can be done to reduce these risk factors?
- Removal and modification of hazards- i.e. remove clutter, rugs, add visual cues
- Increase people’s awareness to hazards with home safety programs- ultimately reducing the exposure to risk.
- Identifying new visual problems and ensuring glasses are appropriate by testing visual acuity and glasses prescription every year.
- Adequate time to adapt to new prescription glasses before increasing activity levels
- Cataract surgery where indicated.
- Review of medication if there are side effects that include visual disturbances.
- Physiotherapy intervention to improve postural sway when combined with moving objects (i.e. catching a ball)