A patient presents with proptosis, strabismus, and a compensatory head tilt (head‑doll posture); what is the most likely diagnosis and how should it be managed?

Thyroid Eye Disease (TED): Most Likely Diagnosis

A patient presenting with proptosis, strabismus, and compensatory head tilt most likely has thyroid eye disease (TED), which requires a multidisciplinary approach combining endocrinology, oculoplastics, and neuro-ophthalmology expertise. 1

Clinical Presentation and Diagnosis

Key Diagnostic Features

• Proptosis with restrictive strabismus is the hallmark presentation of TED, where extraocular muscle enlargement and fibrosis cause mechanical restriction of eye movements 1
• Compensatory head posture (head tilt or turn) develops to maintain binocular single vision, avoid diplopia, or position the eyes in a field where muscle restriction is least problematic 1, 2
• The inferior rectus muscle is most commonly affected in TED, causing restriction of upgaze and vertical strabismus 1
• Patients may demonstrate facial asymmetry with a shorter maxilla on the side opposite to the affected eye in chronic cases 1

Critical Examination Elements

• Perform forced duction testing to distinguish restrictive from paralytic strabismus—TED shows marked restriction on passive movement 1
• Assess ocular torsion preoperatively, as this significantly impacts surgical planning 1
• Measure proptosis using exophthalmometry (normal <21 mm from orbital rim); TED typically shows bilateral proptosis ranging 16-33 mm 3, 4
• Document the pattern and degree of strabismus in all positions of gaze, noting that vertical deviations are most common 1

Differential Diagnosis Considerations

While TED is most likely, the triad of proptosis, strabismus, and head tilt requires ruling out:

• Orbital tumors (cavernous hemangioma, meningioma, schwannoma, metastases) via MRI orbits with contrast 1, 5, 4
• Myasthenia gravis—perform ice pack test (5 minutes for strabismus assessment); variable, fatigable strabismus that improves with rest is pathognomonic 5, 6, 7
• Orbital trauma with muscle entrapment or damage 1
• Superior oblique palsy if head tilt is prominent, though this typically lacks proptosis 1

Management Algorithm

Phase 1: Medical Stabilization

• Achieve euthyroid state first—coordinate with endocrinology to optimize thyroid function 1
• Consider teprotumumab (10 mg/kg initial infusion, then 20 mg/kg every 3 weeks for 8 total infusions) in active TED, which reduces proptosis by mean 2.3-2.8 mm and improves diplopia in 53% of patients 3
• High-dose pulse steroids or orbital radiation may be indicated for severe active inflammation or compressive optic neuropathy 1
• Selenium supplementation in selenium-deficient patients may reduce inflammatory symptoms in milder TED 1

Phase 2: Surgical Sequencing (Critical)

The correct surgical sequence is mandatory to avoid poor outcomes: 1

1. Orbital decompression FIRST (if needed for proptosis or optic neuropathy)

   • Recession of fibrotic rectus muscles predictably worsens proptosis 1
   • Decompression significantly alters ocular alignment, making prior strabismus surgery futile 1
   • Consultation with orbital specialist is warranted when concurrent significant proptosis and strabismus exist 1

2. Strabismus surgery SECOND (after 4-6 months stability)

   • Wait until inflammatory phase has subsided and deviation stable for at least 6 months 1
   • Recession of restricted muscles is the mainstay; resection is generally avoided in restrictive disease 1
   • Large bilateral inferior rectus recession may cause A-pattern exotropia in downgaze and intorsion as superior oblique becomes dominant infraductor 1
   • Systematic approach with intraoperative forced ductions and attention to torsion minimizes undesired results 1

3. Eyelid surgery LAST

   • Eyelid retraction surgery is delayed until after strabismus repair 1
   • Inferior rectus recession may cause lower lid retraction even with careful dissection 1

Surgical Considerations and Pitfalls

• Absorbable sutures (6-0 polyglactin) are preferred for muscle reattachment 1
• Non-absorbable sutures for large inferior rectus recessions may reduce postoperative overcorrection risk 1
• Adjustable suture technique remains controversial—some report better results while others avoid it due to late overcorrection and muscle slippage concerns 1
• Tenon's capsule recession from conjunctiva may augment rectus recession effect and improve postoperative ductions 1
• Preoperative counseling about increased proptosis risk after muscle recession is essential 1

Provider Requirements and Referral

• Experienced ophthalmologist comfortable with complex restrictive strabismus is required for diagnosis and surgical management 1
• Multidisciplinary team including endocrinology, oculoplastics, and neuro-ophthalmology provides optimal care 1
• Orthoptists working under ophthalmologist supervision assist with examination, diagnosis, and nonsurgical management 1

Common Pitfalls to Avoid

• Never perform strabismus surgery before orbital decompression in patients with concurrent significant proptosis—this leads to unpredictable alignment changes and wasted procedures 1
• Do not operate during active inflammatory phase—wait for clinical quiescence and stable measurements for 4-6 months 1
• Avoid assuming isolated superior oblique palsy when proptosis is present—TED can mimic SOP pattern with asymmetric inferior rectus involvement 1
• Do not overlook myasthenia gravis—variable strabismus that changes during prolonged examination requires ice pack testing 5, 6, 7