# Müller muscle conjunctival resection: Impact on Hering’s law and facial symmetry in unilateral ptosis repair

## TL;DR

This study examines how unilateral ptosis surgery affects eyelid and brow symmetry, finding minimal impact from Hering’s law.

## Contribution

The paper is the first to explore bilateral eyelid and brow symmetry after unilateral Müller’s muscle conjunctival resection.

## Key findings

- Significant improvement in ipsilateral eyelid height after surgery.
- Minimal influence of Hering’s law on contralateral eyelid.
- Statistically significant increase in contralateral brow position.

## Abstract

Ptosis is characterized by drooping of the upper eyelid, often requiring
surgical intervention for functional and aesthetic purposes. Müller’s
muscle conjunctival resection is a commonly utilized surgical technique to
correct mild to moderate ptosis. This retrospective study aimed to evaluate
the impact of Hering’s law on the outcomes of unilateral Müller’s
muscle conjunctival resection surgery, particularly eyelid and brow
symmetry.

Thirty patients with unilateral ptosis underwent Müller’s muscle
conjunctival resection. Preand postoperative assessments included
ipsilateral and contralateral side margin-reflex distance and brow position,
measured through digital image analysis.

We found significant improvements in postoperative margin-reflex distance
measurements in the ipsilateral eyelid but not in the contralateral eyelid,
indicating minimal influence of Hering’s law. Brow position showed a
statistically significant increase on the contralateral side but not on the
ipsilateral side.

Müller’s muscle conjunctival resection effectively restores symmetry
in eyelid height and maintains brow symmetry. This is the first study to
explore bilateral eyelid and brow symmetry after unilateral Müller’s
muscle conjunctival resection surgery for mild to moderate ptosis. Further
research should be conducted to understand the long-term effects of
Müller’s muscle conjunctival resection on facial aesthetics,
particularly in relation to brow position.