Falls in Older Populations: Risk Factors and Visual Considerations

Definition: A fall is an event causing a person to unintentionally rest on the ground or a lower level.
Differential Diagnosis: Must distinguish true falls from collapses caused by acute medical issues, such as Acute arrhythmia, Transient ischaemic attack (TIA), and Vertigo.

Frequency: Approximately $30\%$ of individuals aged over $65$ experience a fall annually; $50\%$ of these individuals experience multiple falls within the same year.
Age Risk: The fall rate increases to $60\%$ for individuals aged over $90$ .
Location: Most incidents occur at home; residential facilities report higher numbers due to increased individual risk factors and rigorous reporting.
Economic Burden: Falls cause approximately $250,000$ emergency admissions annually in the UK. Treatment for hip fractures costs approximately pounds $2$ billion per year.
Mortality: Hip fracture patients face a $25\%$ mortality rate within one year of the incident.

Intrinsic Factors: Relate to internal states, diseases, or physiological decline.
Extrinsic Factors: Relate to surroundings, including clothing, spectacles, and environmental hazards.
Key Predictors: History of falls, polypharmacy, cognitive impairment, continence problems (rushing/dehydration), footwear (slippers/socks), and observed unsteadiness.
Osteoporosis: While not a cause of falling, it increases the severity of consequences; $75\%$ of hip fractures occur in women.

Psychosocial Impact: Leads to loss of independence, social isolation, depression, and a "fear of falling" that restricts activities of daily living.
The Mobility Cycle: Reduced movement leads to mobility deterioration, which increases fall risk.
Mortality Correlation: A strong statistical link exists between walking difficulty and mortality, as noted in the Blue Mountains Eye Study (Karpa et al. Arch Ophthalmol $127$ : $1347-1353,2009$ ).

Statistics: Individuals with Visual Impairment (VI) are $1.7$ times more likely to fall and $1.9$ times more likely to suffer hip fractures.
Mechanism: Vision is integral to postural control; closing eyes results in immediate sway.
Critical Deficits:
- Contrast Sensitivity: Essential for detecting steps or uneven terrain.
- Visual Field: Peripheral loss prevents detection of handrails; inferior field loss causes hazards to be missed.
- Depth Perception (Stereopsis): Recent or progressive unilateral loss impairs depth judgments.

Glaucoma: Increases fall risk $3$ times (Haymes et al, $2007$ ).
Cataract: Significant reduction in contrast sensitivity. $30\%$ of those over $65$ fall while on a surgery waiting list (Palagyi et al, $2016$ ).
Surgery Paradox: The risk of falling is $2$ times higher during the period between the first and second eye cataract surgeries compared to pre-surgery levels (Meuleners et al, $2014$ ).

Multifocal Risks: Wearers are $2.29$ times more likely to fall due to image jump, peripheral distortion, and blur when looking at the ground.
Prescription Changes: Major changes ( $> 0.75\,DS$ or $DC$ ) significantly increase risks by altering balance and distance perception (Cumming et al, $2007$ ).
Clinical Recommendations:
- Use small prescription changes rather than full corrections.
- Recommend separate distance-only spectacles for active patients outdoors.
- Avoid introducing multifocals or monovision if the patient is currently stable with distance spectacles.
- NICE Guidelines: Perform risk assessments like "Timed Up and Go" (target $< 12\,s$ to $14\,s$ ) and Refer to NHS Falls Services for exercise and home modifications (e.g., grab rails, high-contrast step edges, avoiding slow-warm-up CFL lamps).