Charles Bonnet Syndrome (CBS)

Charles Bonnet Syndrome (CBS)

Posted under Eye Conditions

I received a recent response from one of our readers of Macular Degeneration News after sending out a newsletter about a not so well known, but not uncommon symptom of advanced macular degeneration. Soon after reading about this symptom, the reader experienced it herself, but was grateful for the advanced knowledge so as not to be alarmed.

The symptom involves seeing things that one knows are not there. Since most people with advanced age related macular degeneration belong to the senior population, this symptom triggers concerns of dementia or other neurological health conditions..

This was the situation my father-in-law found himself in when he began seeing children riding tricycles up and down his driveway when sitting outside or mothers walking with their children on the side of the road when he was riding in the car. My father-in-law has had wet macular degeneration in both eyes for about 5 years. He has no history of dementia, neurological or psychological conditions. He is on very few prescription drugs and there had been no recent changes in his medications.

The name of this symptom is Charles Bonnet Syndrome (CBS). Charles Bonnet Syndrome is named after a Swiss philosopher and biologist who observed this phenomenon in his 87 year old grandfather way back in the 1760’s. His grandfather suffered severe vision loss from cataracts, but was cognitively very alert. Mr. Bonnet was able to associate the detailed images his grandfather was seeing with his vision loss.

There are three main criteria for a diagnosis of CBS according to the authors of Charles Bonnet Syndrome; Visual Loss and Hallucinations CMAJ. 2009 August 4; 181(3-4): 175–176. They are:

1. Visual Loss

2. Clearly formed recurrent visual hallucinations, and

3. Insight into the unreal nature of the hallucinations

My father-in-law was seeing these pleasant scenes regularly – everyday in fact for several months. He had told his primary care doctor about them, but she was not familiar with CBS. Fortunately he told us about the children he was seeing and I was able to explain to him and to my mother-in-law that CBS was most likely the cause of these visions. Feeling quite relieved to know that the hallucinations were not caused by something more serious, my father-in-law became more comfortable sharing about his “visitors” with some of his elderly friends who also have age related macular degeneration. Not surprisingly, several of them shared that indeed they also see things that they know are not there. One lady who had been a quilter all of her life, sees colorful quilts hanging behind people while another friend who is a cat lover, sees beautiful cats in strange places. Find out more about this syndrome, how common it is, who develops it and what my fahter-in-law does to help deal with his visions and visitors:

Charles Bonnet Syndrome – Symptoms and Treatment

Better Health for Better Vision

Leslie Degner, RN, BSN