Müller's Muscle as a New Proprioceptive Organ

Müller's Muscle as a New Proprioceptive Organ Evidence From Immunohistochemical Staining and Electron Microscopy to Verify That the Upper Eyelid Müller's Muscle Contains Proprioceptive Innervation for Reflexive Correction of Eyelid Position

Objectives: Upper eyelid retraction was believed to be maintained solely by voluntary contraction of the levator palpebrae superioris (LPS) and frontalis muscles, together with involuntary contraction of the sympathetically innervated Müller's muscle (MM). However, several studies have suggested that the LPS also undergoes involuntary contractions, and that a visual stimulus may not be the only trigger for frontalis muscle contractions. Recent studies hypothesized that the MM contains proprioceptive neuronal structures, which elicit involuntary LPS muscle contraction by the mesencephalic trigeminal nucleus via a continuous stretch reflex. We aim to identify proprioceptive structures in MM by means of histological examinations.

Methodology: Prospective study. Collaboration of oculoplastics, ophthalmologists and a neuroanatomy specialist in Sheba Medical Center. 50 fresh MM specimens from patients undergoing Müllerectomies will undergo histologic examinations, including immunohistochemical staining and light and electron microscopy.

Significance: Identification of proprioceptive structures in MM will be the first evidence-based proof of a proprioceptive mechanism in the eyelid. This might have a significant impact on future surgical management of eyelid procedures. Comprehensive understanding of the mechanisms underlying eyelid function is especially important in the management of children with ptosis who may have coexisting amblyopia.

Study Overview

• Status: Unknown
• Conditions: Eyelid Movement Disorders; Eyelid Ptosis Congenital
• Intervention / Treatment: Diagnostic test: pathological examination

Detailed Description

The investigators' goal is to find proprioceptive neuronal structures in Müller's muscle (MM). The investigatorswill recruit 50 MM specimens of patients diagnosed with either unilateral or bilateral ptosis who were referred to undergo a posterior approach surgical correction (MMCR). In this surgical approach, the proximal part of MM is removed between the levator palpebrae superioris muscle and the tarsus of the upper eyelids. The excised tissue is generally not used but simply discarded. For study purposed, the investigators will obtain the patients' consent to save these tissues and carry out histologic examinations of the samples. No change in the surgical procedure or the following management will be needed.

• Study Type: Observational
• Enrollment (Anticipated): 50

Contacts and Locations

Study Locations

• Israel
  • Ramat Gan, Israel, 52621
    • Sheba_Medical_Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

patients over 18 years old undergoing Müllerectomies

Description

Inclusion Criteria:

• specimens from patients undergoing Müllerectomies

Exclusion Criteria:

• small specimens (<1 cm length and width)

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
muller muscle; muller muscle and conjunctiva excised during muller muscle conjunctival resection	Diagnostic test: pathological examination; fresh MM specimens from patients undergoing Müllerectomies will undergo histologic examinations

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
presence of proprioceptive organs in the muller muscle	presence of proprioceptive organs in the muller muscle	2 years

Collaborators and Investigators

• Sponsor: Sheba Medical Center

Publications and helpful links

General Publications

• Ben Simon GJ, Blaydon SM, Schwarcz RM, Nakra T, Goldberg RA, McCann JD. Paradoxical use of frontalis muscle and the possible role of botulinum a toxin in permanent motor relearning. Ophthalmology. 2005 May;112(5):918-22. doi: 10.1016/j.ophtha.2005.01.004.

Study record dates

Study Major Dates

• Study Start (Anticipated): January 15, 2018
• Primary Completion (Anticipated): January 15, 2020
• Study Completion (Anticipated): January 15, 2021

Study Registration Dates

• First Submitted: January 5, 2018
• First Submitted That Met QC Criteria: January 5, 2018
• First Posted (Actual): January 11, 2018

Study Record Updates

• Last Update Posted (Actual): January 11, 2018
• Last Update Submitted That Met QC Criteria: January 5, 2018
• Last Verified: January 1, 2018

More Information

Terms related to this study

• Keywords: eyelid; Muller
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Eye Diseases; Eyelid Diseases; Movement Disorders; Blepharoptosis
• Other Study ID Numbers: 4384-17-SMC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No