Horizontal shortening of the lower eyelid margin in facial nerve palsy.

The lower eyelid margin appears to shorten horizontally following FNP. This study provides proof-of-concept for the use of measuring PC distance in patients with FNP as an additional tool for the overall assessment of soft tissue contraction following FNP. It may help identify patients in whom further lower eyelid margin shortening should be avoided and in whom eyelid lengthening may be required.