What are the signs of Horner’s syndrome?
In Horner’s syndrome, the pupil in the involved eye is usually smaller and does not dilate as well as the other eye. The child may have mild ptosis (droopiness) of the upper eyelid [See figure 2]. A subtle but specific finding which is sometimes present is a slight elevation of the lower eyelid (known as inverse ptosis). Because the upper eyelid is slightly lower than normal, and the lower eyelid is slightly higher than normal, the eye may appear smaller. If the Horner’s syndrome developed during the first year of life, the iris on the affected side may appear lighter in color than the uninvolved side (heterochromia). Sometimes, the pressure in the eye is lower in the Horner’s eye and sometimes there is decreased sweating of the skin on the face on the affected side (anhydrosis).
