Horner’s syndrome is usually an indication that there is an underlying medical condition – so early diagnosis and treatment are crucial.

Horner’s syndrome is caused when there is interruption or damage sustained to the nerve channel connecting the brain, face, and eye on one side of the body. This could be due to cerebrovascular accidents, multiple sclerosis, basal meningitis, neck trauma, pituitary tumours, and more.

In children, common causes include neck or shoulder injury during the delivery process; defective aorta during birth; and tumours present in the hormonal and nervous systems.

• Small pupils
• A significant size difference between two pupils
• Slow dilation of the affected pupil in dim light
• Droopy upper eyelid
• Little to no perspiration on the affected side of the face

It is crucial to visit an ophthalmologist to receive an official diagnosis. During the test, the doctor will place eyedrops in both eyes to dilate or constrict the pupils. A comparison is done of the reaction in both eyes to determine if the nerve pathway is damaged.

In some cases, doctors may have patients undergo magnetic resonance imaging (MRI), carotid ultrasound, tomography, and X-ray.

As of now, there is no specific treatment for Horner’s syndrome. However, it will disappear when the underlying medical condition causing it is treated.

This article was contributed by Dr Sunita Padmanabhan, Consultant Ophthalmologist at Pantai Hospital Ampang. To know more about where and when to see Dr Sunita Padmanabhan at her clinic, click here.