Inflammatory Orbital Disease

Symptoms

early: morning eyelid puffiness, redness, and upper lid retraction (ted hallmark)

late: proptosis (prominent eyes), lateral flare, and persistent chemosis

diplopia and a sensation of "pressure" behind the eyes

decreased vision (concerning for dysthyroid optic neuropathy)

idiopathic orbital inflammation (ioi): acute, painful, "explosive" onset

pediatric ioi: may include fever, headache, and lethargy

Clinical Findings

Idiopathic orbital inflammation (ioi)

• "orbit in a hurry": acute painful unilateral proptosis and diplopia
• imaging hallmark: extraocular muscle (eom) enlargement that includes tendon insertions
• diagnostic test: dramatic response to systemic steroids within 24–48 hours
• subtypes: myositic, dacryoadenitic (s-shaped lid), scleroposterior, diffuse, and apical

Thyroid eye disease (ted)

• most common cause of orbital inflammation in adults; usually painless
• eyelid signs: upper lid retraction with lateral flare and lid lag (von graefe sign)
• imaging hallmark: eom enlargement sparing the tendon insertions (muscle belly only)
• muscle frequency: inferior > medial > superior > lateral (imsl)
• associated signs: elevated iop in upgaze and superior limbic keratoconjunctivitis

Systemic correlates

• ted: 80% are hyperthyroid; symptoms include goiter, weight loss, and hand tremor
• concomitants: myasthenia gravis (fluctuating ptosis/diplopia) occurs in a minority

Etiology

Non-specific & autoimmune

• idiopathic orbital inflammation (ioi): nonspecific lymphoplasmacytic inflammation
• thyroid eye disease (ted): autoimmune targeting of orbital fibroblasts
• igg4-related disease: characterized by storiform fibrosis and obliterative phlebitis

Granulomatous & infectious

• sarcoidosis, gpa (wegener), tuberculosis, and syphilis
• infectious mimics: orbital cellulitis, mucormycosis, and aspergillosis

Red Flags

rapid vision loss or apd (optic nerve compression)

bilateral lacrimal gland enlargement (suspect lymphoma, sarcoid, or igg4)

lack of response to steroids within 72 hours (mandates biopsy)

sinus destruction on imaging (suggests gpa or malignancy)

Investigations

Clinical exam

• hertel exophthalmometry to quantify proptosis
• iop in primary and upgaze (correlation with inferior rectus thickening)
• assessment for exposure keratopathy and optic neuropathy (color vision, perimetry)

Imaging (CT/MRI)

• ted: myogenic vs. lipogenic variants; check for apical crowding
• ioi: check for tendon involvement and "ring sign" (scleral thickening)

Systemic & labs

• thyroid panel: tsh, t3, t4, tsi, and tpo antibodies
• inflammatory markers: esr, crp, ana, ace, anca, and serum igg4

Biopsy

• strongly considered for atypical, bilateral, or steroid-refractory cases

Treatment

Thyroid eye disease

• mandatory smoking cessation (smoking significantly worsens ted progression)
• active phase: pulsed iv methylprednisolone or teprotumumab (igf-1r inhibitor)
• mild/stable: lubricants, selenium (100 µg b.i.d.), and head elevation at night
• surgical sequence: decompression → strabismus surgery → eyelid repair

Idiopathic orbital inflammation

• systemic steroids (prednisone 1 mg/kg/day) with slow taper
• steroid-sparing agents (methotrexate, rituximab) for recurrent disease
• low-dose orbital radiation (20 gy) for refractory cases post-biopsy

Igg4-related disease

• systemic steroids followed by steroid-sparing immunosuppression

Clinical Pearl

Idiopathic orbital inflammation is a diagnosis of exclusion — IgG4-related disease, GPA, sarcoid, thyroid eye disease, and lymphoma all mimic it, so biopsy atypical cases before long-term immunosuppression.

Differential Diagnosis

• orbital cellulitis (fever, infectious source)
• orbital lymphoma (painless, "molds" to structures)
• granulomatosis with polyangiitis (gpa)
• orbital metastasis
• myasthenia gravis

Related Adnexa Conditions

• Blebitis
• Blepharitis/Meibomitis
• Congenital Nasolacrimal Duct Obstruction
• Congenital Ptosis
• Contact Dermatitis
• Dacryocystitis
• Dry Eye Syndrome
• Exposure Keratopathy