Botulinum toxin type a for dysthyroid upper eyelid retraction

Area of Science:

• Ophthalmology
• Endocrinology
• Neurology

Background:

• Thyroid eye disease (TED) can cause eyelid retraction, impacting ocular surface health and aesthetics.
• Inflammatory phase TED presents unique challenges for managing eyelid abnormalities.
• Eyelid retraction in TED can lead to exposure keratitis and discomfort.

Purpose of the Study:

• To assess the safety and efficacy of botulinum toxin type A for treating eyelid retraction in active, inflammatory TED.
• To determine the effectiveness of botulinum toxin type A as a temporizing measure for upper eyelid retraction.

Main Methods:

• A prospective, nonrandomized case series involving 18 patients with active TED and upper eyelid retraction.
• Botulinum toxin type A injections (2.5, 5, or 10 U) administered transconjunctivally into the upper eyelid elevator complex.
• Marginal reflex distance 1 (MRD1) was measured to quantify changes in eyelid height.

Main Results:

• 94% of patients (17/18) showed a reduction in MRD1 post-injection, indicating decreased eyelid retraction.
• The average MRD1 decrease was -2.35 mm, with varying degrees of eyelid height reduction observed.
• Minor adverse effects like ptosis and worsened diplopia occurred in some patients but resolved spontaneously.

Conclusions:

• Botulinum toxin type A is a potentially safe and effective treatment for upper eyelid retraction during the inflammatory stage of TED.
• The individual response to botulinum toxin type A is variable.
• This treatment serves as a valuable temporizing measure until surgical intervention is feasible after disease stabilization.