Congenitally enlarged extraocular muscles: can congenital thyroid eye disease exist in a euthyroid infant?

Area of Science:

• Ophthalmology
• Endocrinology
• Pediatrics

Background:

• Thyroid eye disease (TED) typically affects adults with hyperthyroidism.
• Congenital cases of TED are rare, and euthyroid presentations are even less common.
• This case explores TED in an infant with no maternal thyroid dysfunction.

Observation:

• A 2-month-old boy presented with left eye hypotropia, eyelid retraction, and proptosis.
• Imaging revealed enlarged extraocular muscles.
• Both the infant and his mother were euthyroid.

Findings:

• Surgical repair included inferior rectus recession, lower eyelid retractor disinsertion, and entropion repair.
• Muscle biopsy of the inferior rectus and oblique muscles showed no abnormalities.
• The clinical presentation and diagnostic workup strongly suggested thyroid eye disease.

Implications:

• This case represents the first reported instance of euthyroid congenital thyroid eye disease in an infant with a euthyroid mother.
• It highlights the importance of considering TED in infants with specific ocular presentations, even in the absence of thyroid dysfunction.
• Further research may be needed to understand the pathogenesis and diagnostic criteria for congenital euthyroid TED.