Horner syndrome is a rare condition that affects the nerves to the eye and face.
Horner syndrome can be caused by any interruption in a set of nerve fibers that start in the part of the brain called the hypothalamus and travel to the face and eyes. These nerve fibers are involved with sweating, the pupils in your eyes, and the upper and lower eyelid muscles.
Damage of the nerve fibers can result from:
In rare cases, Horner syndrome is present at birth. The condition may occur with a lack of color (pigmentation) of the iris (colored part of the eye).
Symptoms of Horner syndrome may include:
There may also be other symptoms, depending on the location of the affected nerve fiber. These may include:
The health care provider will perform a physical exam and ask about the symptoms.
An eye exam may show:
Depending on the suspected cause, tests may be done, such as:
You may need to be referred to a doctor who specializes in vision problems related to the nervous system (neuro-ophthalmologist).
Treatment depends on the underlying cause of the condition. There is no treatment for Horner syndrome itself. Ptosis is very mild and in rare cases affects vision in Horner syndrome. This can be corrected by cosmetic surgery or treated with eyedrops. The provider can tell you more.
The outcome depends on whether treatment of the cause is successful.
There are no direct complications of Horner syndrome itself. But, there may be complications from the disease that caused Horner syndrome or from its treatment.
Call your provider if you have symptoms of Horner syndrome.
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.