Low Vision Visual Hallucination Syndrome

Charles Bonnet syndrome was discovered by a doctor treating a 69-year-old man who complained of seeing images, including spiders and people sitting in his living room. The patient had been diagnosed six months prior with macular degeneration.

Diagnosis

• According to the American Psychiatric Association, "A hallucination is a sensory perception that has the compelling sense of reality of a true perception but that occurs without external stimulation of the relevant sensory organ." Those with Charles Bonnett syndrome have three common symptoms: visual loss, clearly formed recurrent visual hallucinations, and insight into the unreal nature of the hallucinations.

Loss of Vision

• Charles Bonnet syndrome occurs in patients whose vision has been impaired by between 10 and 30 percent.

Hallucinations

• Patient's hallucinations can include basic shapes to large objects, such as buses, in one's living room. Some patients complain of visual and auditory hallucinations, but there is disagreement as to whether these are actually Charles Bonnet syndrome.

Causes

• According to the Canadian Medical Association, "The specific cause of the hallucinations is unknown; however, they are most commonly attributed to differentiation or lack of true visual input into the brain, which causes a release phenomenon similar to phantom limb symptoms after amputation."

Treatment

• Most patients are not bothered by their hallucinations, so they do not require treatment. However, some patients have reported positive results from taking risperidone, cisapride, carbamazepine, clonazepam, valproate, selective serotonin reuptake inhibitors, gabapentin and olanzapine.