Dementia and Optometry: An Exhaustive Study Guide

Definition and Recognition of Dementia

• Verbatim Definition: Dementia is defined as a "major degenerative disease with substantial cognitive declines from previous performance, which can interfere with the ability to remain independent."

• Diagnosis Statistics: Currently, only approximately $41\%$ of individuals living with dementia receive a formal diagnosis.

• Variability of Impact: The condition affects every individual in different ways; however, seeking help from a General Practitioner (GP) is recommended if memory is declining or if specific signs are noticed.

• Signs and Symptoms to Monitor:

  • Struggling to remember recent events while easily recalling things from the distant past.

  • Difficulty following conversations or television programs.

  • Forgetting the names of friends or common everyday objects.

  • Repeating oneself or losing the thread of a conversation.

  • Other people beginning to comment on the individual's forgetfulness.

  • Problems involving thinking and reasoning.

  • Feeling anxious, depressed, or angry specifically about one's forgetfulness.

  • Confusion even when situated in a familiar environment.

  • A noticeable decline in the ability to tell time, read, or write.

Progression and Severe Symptomology

• As dementia progresses, signs become more severe and include:

  • Impaired judgement and loss of language skills.

  • Difficulties in learning and concentration.

  • Altered sleep patterns and impaired physical coordination.

  • Inability to perform familiar tasks and significant personality changes.

  • Changes in mood, such as depression, and changes in behavior, such as agitation and aggression.

  • Delusions (false ideas) and hallucinations (seeing or hearing things that are not present).

  • Loss of initiative and impaired abstract thinking.

Epidemiology and Public Health Impact

• Economic Cost: The current cost of dementia in the UK is estimated at $\text{£}26\,\text{bn}$.

• Comparison to Other Diseases: Dementia incurs higher health and social care costs ($\text{£}11.9\,\text{bn}$) than cancer ($\text{£}5.0\,\text{bn}$) and chronic heart disease ($\text{£}2.5\,\text{bn}$) combined.

• Future Projections: The cost of dementia in the UK is expected to more than double in the next $25\,\text{years}$, reaching $\text{£}55\,\text{bn}$ by the year $2040$.

• Demographic Shifts: Population pyramids show a significant increase in median age in the UK:

  • $1901\,\text{Census}$: Median age was $23\,\text{years}$.

  • $2001\,\text{Base}$: Median age was $35\,\text{years}$.

  • $2101\,\text{Projected}$: Median age is expected to be $45\,\text{years}$.

• Personal and Social Impact:

  • $77\%$ of people with dementia feel anxious or depressed.

  • $75\%$ of people in the UK believe society is not equipped to deal with dementia.

  • $67\%$ of people with dementia do not always feel part of their community.

  • $61\%$ feel lonely always or some of the time.

  • $48\%$ feel like a burden to their family.

  • $44\%$ feel they lost friends following their diagnosis.

Pathological Changes in the Brain

• Physical Brain Alterations:

  • Atrophy of the cerebral hemispheres.

  • Narrowed gyri and expanded sulci.

  • Meninges thickened by fibrosis.

  • Proliferation of glial cells affecting the grey matter.

  • White matter appears discoloured and vacuolated.

• Cellular and Protein Features:

  • Senile Plaques: Contain beta amyloid protein.

  • Neurofibrillary Tangles: Contain tau protein.

  • Intracellular neuronal cytoplasmic inclusions and Lewy bodies.

• Vascular Dementia: Characterized by the narrowing or blockage of blood vessels, depriving brain cells of nutrients and oxygen. This occurs over a prolonged period rather than suddenly as in a stroke.

Classification of Dementia Types

• Neurodegenerative Diseases:

  • Alzheimer’s Disease (AD).

  • Dementia with Lewy Bodies (DLB).

  • Parkinson’s Disease Dementia (PDD).

  • Fronto-temporal Dementia (FTD).

• Associated with Systemic Disease:

  • Vascular Dementia (VD).

  • Infections, Metabolic issues, or Intoxication.

• Associated with Viruses:

  • Creutzfeldt-Jakob Disease (CJD).

  • Miscellaneous: Trauma and Hydrocephalus.

• Note: Dementias can also be "mixed," involving multiple pathologies.

Trauma-Induced Dementia and Sports

• Professional Football: A study led by the University of Glasgow, published in The New England Journal of Medicine, compared $7,676$ former Scottish male professional footballers to $23,000$ matched individuals. It found that former professional players had approximately a $3.5\times$ higher rate of death due to neurodegenerative disease than expected.

  • Jeff Astle ($1942$-$2002$): Internal inquest ruled his death an "industrial disease" resulting from heading footballs.

  • Peter Bonetti ($1941$-$2020$): Former Chelsea goalkeeper who lived with Alzheimer’s disease.

• Regulatory Changes: To reduce risk, the FA issued guidelines stating children should no longer head footballs during training. The Premier League also introduced concussion substitution trials in $2021$.

• Rugby: Former stars like Steve Thompson (diagnosed at age $42$) have launched legal action against World Rugby. These players have been diagnosed with dementia and probable Chronic Traumatic Encephalopathy (CTE).

• Chronic Traumatic Encephalopathy (CTE): A progressive brain condition caused by repeated blows to the head and repeated episodes of concussion.

Prevalence and Risk Statistics

• General Prevalence by Age:

  • $60$-$65\,\text{year olds}$: $1.7\%$ of the population.

  • Over $95\,\text{year olds}$: $40\%$ of the population.

• Prevalence by Type:

  • Alzheimer’s Disease: $62\%$

  • Vascular Dementia: $17\%$

  • Combined (Mixed): $10\%$

  • Dementia with Lewy Bodies: $4\%$

  • Fronto-temporal Dementia: $2\%$

  • Parkinson’s Disease Dementia: $2\%$

• Risk for Alzheimer’s Disease specifically:

  • <65\,\text{years}: $1$ in $1000$.

  • >65\,\text{years}: $1$ in $20$.

  • >80\,\text{years}: $1$ in $5$.

• Gender and Ethnicity: Two-thirds ($2/3$) of people with dementia are women. Over the age of $80$, females have a slightly greater risk. There are no notable ethnic differences in prevalence.

Cognitive Assessment and Testing

• Common Diagnostic Tools:

  • Mini-Mental State Exam (MMSE): Scored out of $30$. Sections include Orientation, Registration (remembering $3$ objects), Attention/Calculation (subtracting $7$ from $100$ or spelling "World" backwards), Recall, Language, Reading, Writing, and Construction.

  • Mini-Cog: Involves three-word registration, clock drawing (setting hands to $10$ past $11$), and three-word recall.

  • Addenbrooke’s Cognitive Examination (ACE) III.

• Challenges for Visually Impaired (VI) Individuals: Tests often rely on visual tasks (reading, copying drawings, clock drawing). Redesigning tests for VI patients may eliminate sections, affecting the scoring (e.g., the Blind MMSE is scored out of $22$ instead of $30$).

The Relationship Between Dementia and Vision

• Ambiguity in Testing: It is difficult to determine if dementia affects vision directly because:

  • Diagnosis is often not definitive at the time of testing.

  • Mixed conditions and different stages make data inconsistent.

  • Non-specialists often carry out the research.

  • It is unclear if subjective tests measure vision or the ability to perform the test itself.

• Visual Findings in Dementia (Table Overview):

  • Visual Acuity: Usually normal in early stages, may deteriorate later.

  • Eye Movements: Significant in PDD and DLB (fixation defects, saccadic latency).

  • Complex Functions: Defects in reading and visuospatial function in AD/VD; preserved visuospatial function in FTD.

  • Visual Hallucinations: Most common in DLB and PDD.

  • Contrast Sensitivity & Motion Detection: Impaired in AD and VD.

Ocular Findings and Biomarkers

• Objective Visual Pathway Findings:

  • Beta amyloid proteins may be found in the crystalline lens in AD.

  • Abnormal tau proteins found in the retina and optic nerve.

  • Nerve fiber layer (RNFL) and ganglion cell layer thinning visible via Optical Coherence Tomography (OCT).

  • Optic atrophy, disc pallor, and cupping.

• Co-morbidity: Primary Open Angle Glaucoma (POAG) is found in $25\%$ of those with AD. Cognitive function is also linked to the severity of Age-Related Macular Degeneration (AMD).

• Alternative Explanation (Harrabi et al. 2015): Suggests poor cognitive performance in patients with AMD or glaucoma is due to reduced vision leading to reduced physical, social, and mental stimulation.

• Longitudinal Evidence (Hong et al. 2016): The Blue Mountains Eye Study found that visual impairment was not a risk factor for predicting cognitive decline over $5$ and $10\,\text{year}$ follow-ups.

The "Use it or Lose it" Hypothesis and Cognitive Reserve

• Staff et al. 2018 (BMJ): Individuals born in $1936$ were tested at age $11$ and again starting at age $64$. Those who engaged in "intellectual engagement" (reading, problem-solving) had better cognitive abilities.

• Take-home Message: Engagement in intellectual activities does not necessarily slow the trajectory of decline, but starting from a higher level of "cognitive reserve" means it takes longer to reach functional problems.

Impact of Vision Correction on Cognitive Status

• Spectacles: Spierer et al. (2016) found that near visual acuity and wearing reading glasses were associated with higher Blind MMSE scores. Correcting vision may improve day-to-day functioning even if it does not directly change cognitive pathology.

• Cataract Surgery: Surgery is cheap, safe, and effective. Some studies suggest it can improve cognitive status, while others (Elliott et al. 2009) find no effect. Barriers for dementia patients include the risks of general anesthesia for those in poor health and the difficulty of topical anesthesia in severe dementia.

Posterior Cortical Atrophy (PCA)

• Definition: Described as a "visual variant" of Alzheimer’s Disease. It represents about $5\%$ of AD clinic attendees.

• Onset: Typically in the late $50s$ or early $60s$.

• Pathology: Amyloid plaques and tangles are located in the parietal and occipital areas (the "what" and "where" pathways).

• Symptoms: Memory and cognition are relatively preserved, but visual perception is severely affected. Patients may struggle to describe visual difficulties, and descriptions may seem contradictory.

• Specific PCA Symptoms:

  • Simultagnosia: Difficulty understanding busy scenes or seeing more than one object at a time.

  • Difficulty locating objects (e.g., parking, writing, or words moving on a page).

  • Difficulty with fragmented letters or dot-matrix displays.

• Clinical Management of PCA:

  • Use isolated single letters for testing to avoid crowding/confusion.

  • Test visual fields by confrontation and ask the patient to reach out and touch the target.

  • Allow extra "thinking time" rather than talking slowly.

  • Referral to a neurologist and signposting to support groups is essential.

Diagnostic Testing and the Tropicamide Test

• Biomarker Characteristics: Successful biomarkers must be reliable, predictive, reproducible, non-invasive, simple, and inexpensive.

• Tropicamide Pupil Test: First described by Scinto et al. (1994). AD patients have an Acetylcholine (Ach) deficit. Hypothesized that their pupils would dilate excessively even with very dilute ($0.01\%$) tropicamide.

• Controversy: While initially promising (finding a $13\%$ change in pupil size at minute $29$ for AD), subsequent studies were inconsistent. This is explained by the overlap between diseased and healthy populations.

• Sensitivity vs. Specificity:

  • Sensitivity: $\frac{100}{110} = 90.9\%$ (How many abnormals are correctly identified).

  • Specificity: $\frac{90}{95} = 94.7\%$ (How many normals are correctly identified).

Optometric Practice and Domiciliary Care

• Survey (PrOVIDe): $40\%$ of UK optometrists regularly see patients with dementia.

• Domiciliary Visits: Available through the NHS for those unable to leave home. Companies like Visioncall and The Outside Clinic specialize in this, though public awareness is low.

• PrOVIDe Study Findings:

  • $32.5\%$ of dementia patients had Visual Acuity (VA) < 6/12.

  • $50\%$ of this visual impairment was correctable by spectacles.

  • Visual impairment is $2\times$ to $2.5\times$ more common in care homes.

Clinical Management and Communication

• Scheduling: Find the patient's "better" time of day. Consider longer appointments or splitting the exam into multiple visits.

• Success Rates: The PrOVIDe study showed $80\%$ of dementia patients successfully completed almost a full exam, including retinoscopy. Carer presence increases success.

• Communication Strategies:

  • Ensure your face is visible.

  • Use short questions and simple decisions (binary choices).

  • Avoid "elderspeak" (treating them like a child).

  • Provide processing time; do not rush the patient.

  • Address the patient by name frequently.

Mental Capacity and Consent

• Mental Capacity Act 1995: Capacity is specific to each individual decision and time. A person is assumed to have capacity unless proven otherwise.

• Criteria for Capacity:

  • Understanding the information.

  • Retaining the information long enough to decide.

  • Weighing the information.

  • Communicating the decision (even by non-verbal means like blinking).

• Lasting Power of Attorney (LPA): An appointed attorney makes decisions only if the individual lacks capacity.

• Best Interests: If a patient lacks capacity, the clinician/carer must act in their best interest and document the reasoning.

Dispensing and Falls Risk

• Cumming et al. (2007) Study: Found a significantly higher level of falls and fractures in the group receiving new spectacles, especially where "major" prescription changes ($\pm 0.75\,\text{DS/DC}$ or prism changes) were introduced. New spectacles can cause magnification effects and distortion that affect balance and positioning.

• Dispensing Recommendations:

  • Plastic frames with large bearing surfaces are better for delicate skin.

  • Impact-resistant, lightweight lenses.

  • Label spectacles with the patient's name and purpose (e.g., "Distance" or "Reading").

  • Provide clear instructions or photos of the patient wearing the glasses for specific tasks.

Dual Sensory Impairment and Environment

• Hearing Connection: Dawes et al. (2014) highlights a 9x increase in Dual Sensory Impairment (DSI) when comparing youngest to oldest groups. Optometrists should recommend hearing checks.

• Environment: Modify surroundings to be "Bigger, bolder, brighter" to assist those with cognitive and visual decline.

Safeguarding Vulnerable Adults

• Signs of Abuse: Unexplained falls/injuries, bruises in unusual places (inner arm), injuries at different stages of healing, stress/anxiety around certain individuals, and reports of unjustified restraint.

• Practice Policy: All practices must have a safeguarding policy, an appointed lead clinician, and knowledge of how to contact local safeguarding teams.

• Procedure (Observe, Note, Listen, Discuss, Act): Record facts confidentially and separately from standard practice records; report to the safeguarding team in writing.

Dementia Awareness

• Dementia Friends: An Alzheimer’s Society initiative with over $3\,\text{million}$ members. It aims to reduce stigma and change perceptions.

• Organizational Involvement: Optical practices (e.g., Specsavers) can register as Dementia Friendly. This involves staff watching training videos and learning to support customers effectively through eLearning modules.