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Objective Measurement of Eyelid Force in Ptosis Versus Controls
Shani Pillar1,2, Yehoshua Almog1,2, Tal Sharon1,2
1Department of Ophthalmology, Meir Medical Center, Kfar Saba.
The Journal of Craniofacial Surgery
|June 25, 2019
Summary
This study introduces a new, portable force gauge to measure eyelid muscle strength in patients with blepharoptosis and dermatochalasis. Results show significantly lower eyelid forces in these conditions compared to healthy controls, aiding diagnosis and management.
Area of Science:
- Ophthalmology
- Biomechanics
- Surgical Innovation
Background:
- Accurate assessment of upper eyelid function is crucial for diagnosing and managing blepharoptosis.
- Previous research by our group introduced a novel force gauge for evaluating upper lid force in healthy individuals.
Purpose of the Study:
- To apply a novel handheld dynamometer for direct measurement of muscle forces in ptotic eyelids.
- To differentiate between total lid force, levator muscle force, and frontalis muscle contribution in patients undergoing eyelid surgery.
Main Methods:
- A prospective case series enrolled 56 patients undergoing surgical repair for aponeurotic blepharoptosis or dermatochalasis.
- A handheld dynamometer was used to noninvasively measure upward eyelid force with and without frontalis muscle fixation.
- Measurements were compared between ptotic/dermatochalasis groups and a control group (normal contralateral eye if unilateral).
Main Results:
- Patients with ptosis and dermatochalasis exhibited significantly lower total muscle force and levator force compared to controls (P < 0.05).
- Frontalis muscle contribution to upgaze did not significantly differ between the groups.
- In controls, frontalis force strongly correlated with marginal reflex distance 1 (r=0.75, P=0.05).
Conclusions:
- A simple, inexpensive, portable force gauge enables direct eyelid force measurement in eyelid pathologies.
- Demonstrated distinct differences in muscle force between ptotic and healthy eyelids.
- This tool shows potential for improving patient evaluation and guiding management strategies for eyelid disorders.
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