How Does Frontotemporal Dementia Affect the Eyes?

By Your Health Magazine

When there is a discussion about dementia, people often talk about the disease and what it does to the mind. But nobody talks about the changes that other parts of the body go through. Yes, dementia is a disease that deals with memory loss, language problems, and other cognitive issues. However, the neurodegeneration caused by dementia can affect motor skills and the deterioration of other organs like the eyes.

The effect on the eyes is a topic that is not often discussed nor is it understood completely. Cargivers mostly confuse the eyesight problem with other symptoms of dementia but in reality it can be an early indicator of frontotemporal dementia. Here we will be helping you in creating a link between the eyes and dementia to help caregivers better get hands around it.

How Does Dementia Affect Eyesight?

The eye function is greatly impacted due to the neurodegeneration that is caused by dementia. Researches have shown that the advanced frontotemporal dementia eyes field of vision can be around twelve inches. Few individuals have also experienced monocular vision which means they can also see through one eye. There are others who have trouble with depth perception.

Can You Predict Whether Someone Has Dementia or Not from Eyes?

Research suggests that changes in the eyes can provide clues to the early onset of dementia. The eyes are an extension of the central nervous system, and their health is closely linked to the brain.

Retinal Imaging as a Diagnostic Tool:

Studies show that changes in the retina, a layer of cells at the back of the eye, maybe an early indicator of dementia. The retina contains nerve tissue and blood vessels that reflect the health of the brain. Techniques such as optical coherence tomography (OCT) can detect thinning of the retinal nerve fiber layer, which has been associated with Alzheimer’s disease and other forms of dementia.

Pupil Reactions:

Changes in pupil response to light have also been studied as a potential marker. Individuals with dementia may exhibit slower or irregular pupil reactions due to impaired autonomic nervous system function. Research in this area is ongoing, but pupil dynamics could one day serve as a non-invasive biomarker for cognitive decline.

Visual Field Deficits:

Early dementia can manifest as subtle changes in the visual field, such as difficulty detecting peripheral objects. These deficits are often overlooked but can provide additional clues to cognitive health.

While eye-based diagnostics are not yet definitive for diagnosing dementia, they hold promise for early detection, especially when combined with other cognitive and neurological assessments.

Is There a Direct Effect of Frontotemporal Dementia on Eyes?

Frontotemporal dementia (FTD) is a specific type of dementia that primarily affects the frontal and temporal lobes of the brain. Unlike Alzheimer’s disease, which typically begins with memory loss, FTD is characterized by changes in behavior, personality, and language. Its effects on eyesight are less direct but still significant.

Visual Processing Challenges:

FTD can disrupt higher-order visual functions controlled by the brain. This means individuals may struggle with recognizing faces (prosopagnosia), interpreting complex scenes, or judging spatial relationships. These impairments are more about how the brain processes visual input than about the physical health of the eyes. Due to this challenge the frontotemporal dementia eyes look different in comparison to other types of dementia.

Eye Movement Abnormalities:

Studies suggest that individuals with FTD may exhibit unusual patterns of eye movement. They might fixate less efficiently on objects or show difficulties in smooth pursuit eye movements, which involve tracking a moving target. These changes can complicate daily activities like reading or driving.

Peripheral Vision and Awareness:

In some cases, FTD affects peripheral vision by impairing the brain’s ability to process stimuli from the edges of the visual field. This can increase the risk of accidents or collisions in crowded or busy environments.

Although the changes in vision due to FTD are secondary to its primary cognitive symptoms, they can significantly impact an individual’s quality of life and ability to function independently.

Are There Any Miscellaneous Indicators in Eyes for People Suffering With Dementia?

Yes, there are several miscellaneous indicators in the eyes that can be associated with dementia, particularly Alzheimer’s disease:

Visual Hallucinations: People with dementia may experience seeing things that aren’t there. These hallucinations can be simple, like spots or flashes of light, or more complex, like people or animals.
Difficulty with Contrast Sensitivity: This refers to the ability to distinguish between shades of the same color. People with dementia may struggle to see objects against a similar background, such as reading black text on a gray background.
Impaired Depth Perception: This can lead to difficulties with judging distances, which can be dangerous, especially when crossing the street or navigating stairs.
Changes in Pupil Response: The way the pupils react to light can be altered in people with dementia. This can be due to damage to the brain’s visual pathways.
Eye Movement Abnormalities: People with dementia may have trouble tracking moving objects with their eyes or focusing on a specific point. This can be due to damage to the brain’s frontal lobes, which are involved in controlling eye movements.

Conclusion

Dementia’s harmful effects extend to eyesight, even in the absence of physical eye injury. Brain-related visual processing and eye movement difficulties, particularly in frontotemporal dementia eyes, could be early warning signs. Emerging eye-based biomarkers like retinal imaging and pupil response can aid in early detection. So, make sure to take any change into immediate consideration.