What is the recommended management for thyroid eye disease?

Management of Thyroid Eye Disease

Thyroid eye disease management must be stratified by disease activity (Clinical Activity Score) and severity, with treatment sequenced from conservative measures in mild disease to urgent orbital decompression for sight-threatening complications, while maintaining euthyroidism and mandating smoking cessation throughout. 1

---

Initial Assessment and Risk Stratification

Document baseline disease severity using:

• Exophthalmometry to quantify proptosis 1
• Clinical Activity Score (CAS) ranging 0–7, with CAS ≥3 indicating active inflammation and CAS ≥5 demonstrating moderate-to-severe active disease 1
• Visual acuity, color vision, visual fields, pupillary examination, and fundus examination to screen for compressive optic neuropathy 1, 2
• Diplopia assessment in primary gaze and reading position 1
• Orbital CT or MRI showing tendon-sparing enlargement of extraocular muscles (most commonly inferior rectus, then medial rectus) 1, 2

Identify modifiable risk factors that worsen prognosis:

• Smoking dramatically increases disease severity and must be stopped immediately 1, 2
• High free T3 and T4 levels correlate with worse eye symptoms; achieve and maintain euthyroidism 2
• Low serum selenium levels increase inflammatory symptoms 1, 2
• Male gender and family history of thyroid disorders predict more severe manifestations 2

---

Management Algorithm by Disease Severity

Mild Disease (CAS < 3, No Diplopia or Optic Neuropathy)

Conservative management is appropriate when there is no diplopia in primary gaze, no optic nerve involvement, and no severe corneal exposure: 1

• Apply artificial tears regularly and lubricating ointments at night to prevent exposure keratopathy from lid retraction and mild proptosis 1, 3
• Insert punctal plugs to enhance tear retention when lubrication alone is insufficient 1
• Supplement selenium in patients with documented selenium deficiency to mitigate inflammatory symptoms through antioxidant effects 1, 4
• Observe with serial examinations as long as the clinical picture remains stable 1

Escalate therapy immediately if any of the following develop:

• Diplopia in primary gaze or reading position, signaling restrictive myopathy 1
• Decreased visual acuity, color vision loss, or relative afferent pupillary defect indicating compressive optic neuropathy 1, 2
• Severe corneal ulceration despite maximal lubrication 1

---

Moderate-to-Severe Active Disease (CAS ≥3, Diplopia Present, No Vision Threat)

Systemic corticosteroids are the first-line treatment for active moderate-to-severe disease: 3, 4, 5

• High-dose intravenous methylprednisolone followed by oral taper reduces inflammatory symptoms and long-term sequelae 3, 6, 5
• Adjunctive fractionated low-dose orbital radiotherapy serves as a steroid-sparing measure in patients with active inflammation 3, 6, 5

Teprotumumab (FDA-approved for thyroid eye disease regardless of activity or duration) effectively reduces proptosis and CAS in patients with active disease: 1, 7

• Counsel patients about hearing risk before initiating treatment; establish baseline audiometry and monitor throughout therapy 1
• Teprotumumab also carries risks of hyperglycemia and is contraindicated in pregnancy 1
• Consider teprotumumab with caution in patients with pre-existing hearing loss 1

Manage diplopia conservatively during the active phase:

• Fresnel or ground-in prisms provide temporary relief while awaiting disease stabilization 1
• Chemodenervation may offer temporary diplopia relief and possibly reduce final misalignment 1
• Do not perform strabismus surgery during active inflammation, as the deviation will continue to change 1

---

Sight-Threatening Disease (Compressive Optic Neuropathy or Severe Exposure Keratopathy)

Urgent orbital decompression, high-dose corticosteroids, or orbital radiation must be initiated without delay for compressive optic neuropathy or corneal ulceration despite maximal lubrication: 1, 6, 5

• Start high-dose intravenous methylprednisolone immediately for rapid visual improvement 8, 6
• Perform urgent orbital decompression (deep medial wall and floor) if there is vision loss, an afferent pupillary defect, or abnormal color vision 1, 6
• Do not postpone decompression surgery while attempting medical therapy when vision is threatened 1
• Early tarsorrhaphy protects the ocular surface from severe exposure in patients with marked lid retraction 6

---

Surgical Rehabilitation Sequence (Inactive Disease Only)

Surgery must be delayed until the inflammatory stage has subsided and measurements have been stable for at least 6 months: 1

The surgical sequence must follow this strict order to avoid undesired outcomes:

1. Orbital decompression first (if needed for proptosis or persistent optic neuropathy after medical therapy) 1, 3

   • Decompression commonly worsens or creates new strabismus, so it must precede muscle surgery 1
   • Counsel patients preoperatively that muscle recession—especially inferior rectus—will typically increase proptosis, requiring concurrent decompression evaluation when significant proptosis is present 1

2. Strabismus surgery second to address diplopia 1, 3

   • Recession of restricted muscles is the mainstay; resection is generally avoided in restrictive disease 1
   • Vertical deviations are more challenging than horizontal deviations (66% vs 84% success after primary surgery) because the inferior rectus is most commonly affected 1
   • Systematic preoperative and intraoperative assessment of forced ductions and ocular torsion minimizes undesired outcomes 1
   • Recession of inferior rectus carries specific risks: lower lid retraction, consecutive hypertropia, and A-pattern exotropia in downgaze 1
   • Absorbable sutures (6-0 polyglactin) are generally preferred, though non-absorbable sutures may reduce postoperative drift in large inferior rectus recessions 1
   • Adjustable suture technique remains controversial due to overcorrection and muscle slippage concerns 1

3. Eyelid surgery last to correct retraction 1, 3

   • Earlier surgeries affect lid position, so eyelid repair must be the final step 1
   • Do not perform eyelid surgery before strabismus repair, as muscle surgery affects lid position 1

---

Critical Pitfalls to Avoid

• Do not perform strabismus surgery during active inflammation, as the deviation will continue to change 1
• Do not perform eyelid surgery before strabismus repair, as muscle surgery affects lid position 1
• Do not underestimate the complexity of vertical deviations in thyroid eye disease, particularly inferior rectus involvement 1
• Do not forget preoperative counseling about potential worsening of proptosis with muscle recession surgery 1
• Do not assume ocular myositis without first evaluating thyroid function, as thyroid eye disease is far more common and mimics the same clinical triad 1
• A small percentage of thyroid eye disease patients have co-existent myasthenia gravis; forced-duction testing differentiates the two (positive forced duction supports thyroid eye disease, negative test with fatigable weakness points toward myasthenia gravis) 1, 9

---

Multidisciplinary Coordination

Management requires an experienced ophthalmologist comfortable with complex strabismus and severe restrictive disease, working in coordination with endocrinology to achieve and maintain euthyroidism throughout the disease course. 1, 3