Posterior Cortical Atrophy: 15 Signs Dementia Could be Causing Vision…
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Memory loss isn’t the only common symptom for those with dementia. A senior with dementia can also experience vision impairment. Losing sight can be confusing, disorienting, and frightening to a senior who may respond with strange reactions. Family caregivers may mistakenly think the senior may be having visual hallucinations.

To better understand visual impairment, try holding your hand up in front of one eye. Unlike affected seniors, you will know the cause of your partial vision impairment and can easily remove your hand and see clearly again.

Defining Vision Loss: Posterior Cortical Atrophy

The medical term for reduced vision due to dementia is Posterior Cortical Atrophy (PCA). To better explain this term, let’s break it up and define each separate word:

  • “Posterior” means the back part of the brain
  • “Cortical” means the thinking outer layer of the brain
  • “Atrophy” means shrinkage of that area of the brain

The complete term is confusing for and not easily remembered by family caregivers without professional healthcare experience. An easier term for this condition is PCA (not to be confused with a Personal Care Attendant).

Causes of Posterior Cortical Atrophy

Grandson and Grandma together in picture

You may be familiar with the “plaques” and “tangles” in the brain which lead to Alzheimer’s disease. The same protein which forms these plaques and tangles builds up in the back part of a senior’s brain and leads to Posterior Cortical Atrophy.

For a better visual, have you ever played the “Telephone Game”? In this game players line up side-by-side and the first player whispers a message into the ear of the second player and so on. By the end of the line, the message is repeated and is often completely garbled.

A similar process happens with PCA where messages received by the human eyes are not completely or correctly reached by the brain. These blocked or misunderstood messages are then not able to be processed by the brain.

With the cause of Alzheimer’s disease and PCA being similar, a misdiagnosis can happen. The two conditions, however, have vastly different results. Those with Alzheimer’s disease can lose their memory, language, and some motor skills. PCA patients may keep memory and language skills, but demonstrate declining vision and literary skills.

Losing memories of one’s own family, career, and life due to dementia can be immensely difficult to watch and/or experience. PCA’s symptoms may be milder than Alzheimer’s disease. Although PCA also causes loss in memory and cognition, it often occurs at a younger age than Alzheimer’s disease. While PCA is almost always caused by Alzheimer’s disease, it can also result from dementia with Lewy bodies and Creutzfeldt-Jakob disease.

Symptoms of Posterior Cortical Atrophy

Caregivers should watch and listen for concerns about any, or all, of the following:

1. Trouble recognizing people

Those with PCA may not immediately recognize familiar objects or people. People becoming strangers could include family, friends, and television/otherwise pictured characters. Those with PCA may also not recognize familiar colors and may identify these as completely different colors.

Caregiver tips:

  • Avoid correcting the senior’s mistake. Doing so can lead to arguments and/or hurt feelings.
  • Wear familiar clothing and cologne/perfume. This may help the senior with dementia recognize you.
  • Focus on doing familiar activities together like gardening, walking, or solving puzzles.
Senior doing yoga outside with caregiver

2. Problems with judging spatial differences between objects

Does your loved one press the wrong numbers on a telephone keypad? Misjudge the distance to reach a doorknob? Overlook something directly placed in front of him/her? Miscalculate the distance between vehicles when driving? These actions taken by a senior could be caused by PCA.

Caregiver tips:

  • Replace their telephone with another model with larger numerical keys.
  • Hold and guide the senior’s hand toward their desired object.

3. Misjudging distances

A common example here is misjudging the distance between stairs. Seniors with dementia often fall down or up the stairs – potentially causing severe injury.

Caregiver tips:

  • Differentiate each step with another color. Replace the carpet or paint stairs in alternating colors. You could also apply a piece of duct tape to the lip of each stair to signify the separation.
  • Consider installing a motorized stairlift to take a senior up or downstairs without risk.

4. Reading problems

Your loved one may struggle with reading a book or a newspaper. He or she may skip over one or more lines of text while relying on a finger as a guide.

Caregiver tips:

  • Offer books with larger print and a more straightforward font like Times New Roman.
  • Supply the senior with a magnifying glass to use.
  • Read books or news articles out loud.
Older lady reading with a magnifying glass

5. Blurring vision

Blurring is when someone sees things less clearly or sharply. Faces and common objects can become harder to recognize. Blurring can cause confusion and difficulty finding objects. Blurring can make it a challenge to read or write.

Caregiver tips:

  • Make it clear who you are when interacting with a person with dementia. For example, instead of saying, “It’s me,” say, “Hi Mom, it’s Bob, your son.”
  • When you give the senior an object, say what it is. For example, say, “Here is your hairbrush.”

6. Pupils reacting slowly to light

Slow reactions to light make it hard to go from a light space to a dark space. When a person with dementia turns away after looking out of a bright window, the room will appear dark. Going outside on a sunny day can be overwhelming. The light appears too bright until their pupils react.

Caregiver tips:

  • Allow plenty of time to adjust to different levels of light.
  • When waking up in the morning, keep the lights low. Turn on a small light first.
  • Go slowly when entering from outside. Wait patiently inside the door until their eyes adjust.
  • Encourage your care partner to shield their eyes from the sun and wear a wide-brimmed hat or sunglasses outside.
  • Reduce glare and shadows in the house with blinds and adequate lighting.
Caregiver with Senior in nature outside

7. Smaller visual field

Your visual field is the area around you in which you can see things. Dementia causes this field to become smaller. With dementia, the visual field can narrow to only 12 inches. Try cupping your hands in a circle around your eyes to better understand this problem. Teepa Snow, a dementia educator, describes this smaller visual field as "like trying to move around while wearing binoculars."

This means that when a person with dementia is moving around they see much less than you do. A bathroom door in “plain sight” might not be seen. It is normal to have a smaller visual field as you age, but with dementia, the visual field is much smaller.

Caregiver tips:

  • You can use large pictures to help a loved one with dementia find common things. A large picture that is easy to see can help identify where to find something, like a mug.
  • Use bright colors. Contrasting colors are easier to see. A bright colored plate on a light colored table will be more noticeable. Contrasting colors make it easier to see the food as well.

8. Loss of peripheral vision

Peripheral vision is when you can see things that are not directly in front of you. You see things “out of the corner of your eye.” A loss in peripheral vision causes difficulty seeing objects around you. This vision loss can lead to falls, tripping over chairs, or bumping into door frames.

A person with dementia may not see you if you come up to them from behind or the side. Without peripheral vision they will only be able to see a plate of food in front of them.

Caregiver tips:

  • Keep in mind that the person with dementia may only see things directly in front of them. You might startle or frighten them if you approach from behind. Try to stand directly in front of them before you speak.
  • Serve finger foods at meal time. These are easier to recognize, and can be more straightforward as utensils can become more difficult to use. If you are helping with feeding, try to direct the person to look at the food before offering a bite.

9. Problems with depth perception

Advanced dementia can cause the brain to see from only one eye. What they see can become too much for the brain to process, so to cope, the brain only uses information from one eye. This affects the ability to know how far they are from an object. The difference between a flat surface or a raised surface may not be clear.

You might notice your care partner steps too highly over a change in flooring. They could be trying to go around a shadow. Without depth perception, the dark spot may look like a hole.

A loss of depth perception can cause strange behaviors. Seniors may pick at the air around them. They may be trying to touch something but can’t tell how far away it is. When they pick at the air in front of them, they may be trying to turn off a ceiling light.

Caregiver tips:

  • Avoid placing dark rugs on the floor.
  • Increase the amount of lighting. A dark corner may appear frightening.

10. Sensitivity to bright lights or shiny surfaces

Caregivers may notice that their loved one shies away from bright lights and/or shiny surfaces.

Caregiver tips:

  • Replace light bulbs with a lower wattage bulb.
  • Ensure that all lamps have shades covering the bulb.
  • Provide your senior with a wide-brimmed hat to wear outside. This can be very effective with blocking the bright sun. Sunglasses can also be useful.
  • Take over the driving responsibilities for a senior or make other transportation arrangements so the senior will not have to drive.

11. Anxiety

Losing one’s sight can be a very frightening thing to experience. Imagine facing the task of climbing or descending stairs and wondering if you might fall. Imagine recognizing preliminary or partial vision loss and questioning if it will worsen. Imagine losing your ability to see and connect with your family, other caregivers, and once-familiar objects and surroundings.

Caregiver tips:

  • Try using supplements. Lemon balm, green tea, and valerian root are among the number of natural supplements which have been shown to reduce anxiety. Ask a doctor for recommendations and understand how supplements work. It may be two or three months before any improvement is seen.
  • Consider your surroundings. Is your loved ones omewhere busy or noisy?
  • Hold their hand or offer a soothing hug.

12. Irritability

Seniors may also demonstrate an annoyance with vision loss. This can demonstrate physical decline – something that many people do not like to readily admit. Without a cure for this blindness, a senior with dementia may also be on-edge and be quick to anger.

Caregiver tips:

  • Exercise patience with the senior and try to understand that this irritability has nothing to do with you.
  • Reduce caffeine. Drinking too much coffee can lead to heightened irritability. Cut back on the number of coffees served throughout the day or offer decaffeinated coffee instead.
  • Take the senior to a quiet place. A more peaceful and relaxed environment can be very calming.

13. Apathy

Alternatively, a senior with vision loss may simply “give up” and accept the condition without any fight. This can be unfortunate, heartbreaking, and tragic to watch. Any apathy felt by the senior may cascade over into other areas (e.g. the senior may not care when you plan to drop by to visit, when you book his/her next medical appointment, or what is served for dinner).

Caregiver tips:

  • Revisit past joys. Reintroduce the senior to a once-loved hobby or pastime. Serve the senior’s favorite food.
  • Change the senior’s bedtime and wake-up time. Apathy often leads to physical and mental exhaustion – meaning the senior may be taking more naps than usual. Family caregivers could point this out to long-term care home staff and suggest that the senior be sent to bed earlier. Aim for an uninterrupted seven to eight hours of sleep per night.
  • Monitor the senior’s diet. What are they eating? Reduce the amount of sugar, frozen foods, and preservatives. Choose fresh fruits, vegetables, fiber, and other natural foods instead.

14. Difficulty using familiar objects

Typing at a computer may seem simple enough; however, seniors with PCA may struggle with tasks – and objects to make those tasks easier.

Caregiver tips:

  • When it comes to vision loss, bigger is often better! Telephone keypads now feature larger keys. Calendars often feature larger print and date boxes.
  • Be supportive. Allow your loved one to vent when and where necessary. Your listening ears and sympathetic shoulder can be of immense help.

Treatment for PCA

At this time, there is no known cure for posterior cortical atrophy. Doctors do not have an answer yet, and will often prescribe medications to treat a person’s symptoms. You can expect to add prescriptions for anxiety and/or depression to a senior’s medication list.

Doctors may also suggest that the senior get physical, occupational, and/or cognitive therapy. Other drugs, including donepezil (Aricept®), rivastigmine (Exelon®) and galantamine (Razadyne®), can help the symptoms of PCA by boosting the function of brain cells to compensate for damage caused by Alzheimer’s disease. With a proper treatment plan, a senior diagnosed with PCA can often live 10 – 12 years past the original diagnosis.

Medication for vision

How to Help a Person Cope with Vision Changes

Visual difficulties can cause frustration for the caregiver. Here are a few tips which may help both you and your loved one better manage and cope:

  • Understand the why behind strange behaviors. Both you and your loved one don’t have to be confused about what is happening. It may be better for you to know the reason for any odd actions and what to expect in the future.
  • Rearrange the environment to make it safer for the person with vision loss or dementia.
  • Become familiar with the normal changes in vision that occur. If you notice any vision changes because of dementia, see either an ophthalmologist or optometrist for regular eye exams. Depending on the exam results, your loved one may be referred to a neurologist.
  • Allow for extra time to complete regular activities. Slow down and offer plenty of encouragement. See the world through the eyes of a person with dementia.

Don’t forget to find support for yourself. Dementia behaviors can be strange and frustrating. You may feel alone and confused. Attending a dementia support group can help you better understand these behaviors.


Causes of Visuoperceptual Difficulties

How Alzheimer’s Disease Affects Vision and Perception

A Form of Dementia that Affects Vision: Posterior Cortical Atrophy

Aging and Your Eyes

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About the Author(s)

Crystal Jo is a Registered Nurse who is passionate about helping older adults live happy, healthy lives at home. As a freelance writer, she enjoys educating and inspiring seniors, and those who love them, to choose a healthy life.

As a former co-caregiver, Rick Lauber helped and supported his own aging parents. His mother had Parkinson's and Leukemia and his father had Alzheimer's. Rick learned that caregiving is challenging and used writing to personally cope.

His stories became two books, Caregiver's Guide for Canadians and The Successful Caregiver's Guide.

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