Problem with vision could be an early sign of Alzheimer's Disease

An older woman having vision problems

A neurologist has warned that a problem with vision can be an early sign of dementia, and she wants people to be aware so the condition can be detected sooner. Researchers working with the University of California in San Francisco have discovered that the very first signs of dementia could be flagged up by ophthalmologists if they know how to look for posterior cortical atrophy or PCA, also known to doctors as Benson’s syndrome.

The condition is sometimes described as a visual variant of Alzheimer’s disease, impacting areas in the brain responsible for spelling, calculation, spatial perception and complex visual processing. Dr Marianne Chapleau, a neurologist from the University of California in San Francisco Department of Neurology, argues that diagnosing PCA faster and more often could help many more patients who are in the first stages of developing Alzheimer’s disease.

She said: “Most patients see their optometrist when they start experiencing visual symptoms and may be referred to an ophthalmologist who may also fail to recognize PCA. We need better tools in clinical settings to identify these patients early on and get them treatment.”

Importantly, for the early diagnosis of dementia, the signs of PCA become apparent before the age of 60, on average. This is usually before the first signs of memory loss and confusion appear in those developing Alzheimer’s disease, reports The Express. Dr Chapleau’s full research paper was published in The Lancet.

It states that people with PCA first visit a doctor on average 3.8 years after symptoms appear. Unfortunately, by this time according to Dr Chapleau and her colleagues, mild or moderate symptoms of dementia are in evidence.

When diagnosed, a large number of sufferers of PCA showed signs of what’s known as “constructional dyspraxia, space perception deficit, and simultanagnosia.” Constructional dyspraxia is an inability to copy a drawing or build a simple model. Space perception deficit is when a patient has problems identifying the location of something they see, hear or feel. Simultanagnosia is a visual disorder that refers to when a patient has problems paying attention to more than one object at a time. Additionally, nearly half had problems doing simple sums and reading text.

Researchers believe that PCA is still underdiagnosed and they want to make more people aware of the disorder and its links to diagnosing dementia at an early stage. There is more information about lesser-known causes of dementia via the NHS and the Alzheimer’s Society has a section on posterior cortical atrophy.

Alzheimer’s disease symptoms

According to the NHS, the symptoms of Alzheimer’s disease progress slowly over several years. Sometimes these symptoms are confused with other conditions and may initially be put down to old age.

The rate at which the symptoms progress is different for each individual. In some cases, other conditions can be responsible for symptoms getting worse.

These conditions include:

• infections
• stroke
• delirium