Which statement best describes the typical exam finding in Horner's syndrome?

Which statement best describes the typical exam finding in Horner's syndrome?

• A. Ptosis with mydriasis
• B. Ptosis with miosis
• C. Ptosis with exophthalmos
• D. Ptosis with cycloplegia

Answer: (B)

Horner's syndrome occurs when the oculosympathetic pathway to the eye is disrupted, so the eye loses sympathetic input. That means the pupil cannot dilate and becomes constricted (miosis), while Mueller's muscle in the eyelid loses its tone, producing mild ptosis. The combination of ptosis with miosis on the affected side is the classic exam finding, often with anisocoria that is more evident in dim light due to the limited dilation. Exophthalmos would suggest forward protrusion of the eye, which isn’t typical here; cycloplegia reflects paralysis of accommodation from parasympathetic disruption, not the sympathetic loss seen in Horner's. This is why ptosis with miosis best describes the typical exam finding.

Horner's syndrome occurs when the oculosympathetic pathway to the eye is disrupted, so the eye loses sympathetic input. That means the pupil cannot dilate and becomes constricted (miosis), while Mueller's muscle in the eyelid loses its tone, producing mild ptosis. The combination of ptosis with miosis on the affected side is the classic exam finding, often with anisocoria that is more evident in dim light due to the limited dilation. Exophthalmos would suggest forward protrusion of the eye, which isn’t typical here; cycloplegia reflects paralysis of accommodation from parasympathetic disruption, not the sympathetic loss seen in Horner's. This is why ptosis with miosis best describes the typical exam finding.