[Endocrine orbitopathy. Interventions on the external eye muscles]

Area of Science:

• Ophthalmology
• Endocrinology
• Surgical Science

Context:

• Graves' disease frequently causes eye motility disorders, including diplopia, abnormal head posture, and eyelid malposition.
• Fibrotic changes in eye muscles are a common complication, necessitating surgical intervention.
• Existing literature provides varied approaches to surgical correction.

Purpose:

• To review and synthesize the literature on eye muscle surgery outcomes in Graves' disease.
• To establish precise indications and surgical techniques for optimal correction of motility disorders.
• To evaluate the impact of surgical interventions on visual function and eyelid position.

Summary:

• Recessing a single fibrotic eye muscle for strabismus up to 15 degrees provides reproducible results, independent of the initial deviation angle.
• Surgical indications, including the amount and side of muscle recession, depend on the type of deviation and head posture.
• Improvements in the fusional visual field are observed in nearly all cases; however, hypercorrections can occur with certain surgical adjustments.
• Surgery on vertical rectus muscles can improve upper-lid retraction, while lower-lid retraction is not consistently affected by inferior rectus recession.
• A stable preoperative condition (≥6 months) and realistic postoperative expectations are crucial for successful outcomes, advising against premature revisions.

Impact:

• Provides a clear framework for surgical planning in Graves' ophthalmopathy, optimizing patient outcomes.
• Enhances understanding of the relationship between specific surgical techniques and functional improvements, such as visual field expansion.
• Contributes to evidence-based guidelines for managing complex eye motility and eyelid abnormalities in Graves' disease patients.