Orbital inflammation

Idiopathic orbital inflammation (formerly pseudotumor of the orbit) is a rare pathology that is a non-neoplastic, non-infectious, volumetric lesion of the orbit. The inflammatory process can involve any or all soft tissues in the orbit.

Histopathologically, it is a polymorphic cellular inflammatory infiltration that develops into reactive fibrosis. The course of the process is not determined by its clinical and pathological characteristics. In adults, the disease is unilateral; in children, it can be bilateral. Simultaneous involvement of the orbit and sinuses is rare.

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Symptoms of orbital inflammation

It manifests itself in the 3rd to 6th decades of life with acute redness, swelling and pain, usually on one side.

Signs

• Congestive exophthalmos and ophthalmoplegia.
• Impaired function of the optic nerve when inflammation spreads to the posterior parts of the orbit.

The flow has several variants:

• Spontaneous remission after a few weeks without consequences.
• Long-term intermittent course without complete remission with episodes of exacerbation.
• Severe, prolonged course, leading to progressive fibrosis of the orbital tissues and ultimately to a “frozen” orbit, characterized by ophthalmoplegia, possibly combined with ptosis and deterioration of vision due to involvement of the optic nerve in the process.

Acute dacryoadenitis

Lacrimal gland involvement occurs in approximately 25% of cases of idiopathic orbital inflammation. However, dacryoadenitis is more often isolated and spontaneously resolves without requiring treatment.

Clinical features

It manifests itself as acute discomfort in the area of the lacrimal gland.

Signs

• Edema of the outer part of the upper eyelid leads to the appearance of a characteristic S-shaped ptosis and slight downward and inward dystopia.
• Pain in the area of the lacrimal gland fossa.
• Injection of the palpebral portion of the lacrimal gland and adjacent conjunctiva.
• A decrease in tear production may be observed.

Differential diagnostics

1. Inflammation of the lacrimal gland is observed with mumps, mononucleosis and, less commonly, bacterial infection.
2. A ruptured dermoid cyst can lead to inflammation in the area of the lacrimal gland.
3. Malignant tumors of the lacrimal gland can cause pain, but the onset is usually not acute.

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Tolosa-Hunt syndrome

A rare condition that is a granulomatous inflammation of the cavernous sinus, superior orbital fissure, and/or orbital apex. The clinical course is characterized by remissions and exacerbations.

It manifests itself as diplopia, accompanied by pain in the ipsilateral orbit or in the half of the head corresponding to the location of the pain.

Signs

• Exophthalmos, if present, is not pronounced.
• Paralysis of the oculomotor nerve, often with internal ophthalmoplegia.
• Impaired sensitivity along the first and second branches of the trigeminal nerve.

Treatment: systemic steroid therapy.

Wegener granulomatosis

Wegener's granulomatosis usually affects both orbits, spreading from the adjacent sinuses or nasopharynx. The orbit is less commonly affected initially. Wegener's granulomatosis should be considered in all cases of bilateral orbital inflammation, especially when associated with sinus involvement. Detection of antineutrophil cytoplasmic antibodies is a very useful serologic test.

Signs

• Exophthalmos, signs of orbital congestion and ophthalmoplegia (often bilateral).
• Dacryoadenitis and nasolacrimal duct obstruction.
• Associated with scleritis and marginal ulcerative keratitis.

Treatment

• Systemic cyclophosphamide and steroids are highly effective. In resistant cases, cyclosporine, azathioprine, antithymus globulin, or plasmapheresis may be effective.
• In cases of severe orbital involvement, surgical decompression of the orbit may be necessary.

Treatment of orbital inflammation

1. Observation in case of relatively mild course in the hope of spontaneous remission.
2. A biopsy may be required in persistent cases to confirm the diagnosis and rule out a tumor.
3. Systemic steroid administration is effective in 50-75% of patients in moderate to severe cases. Initial oral doses of prednisolone are 60-80 mg per day, tapered to complete discontinuation depending on effectiveness and possibly re-administered in case of relapse.
4. Radiotherapy may be prescribed if adequate steroid therapy is ineffective within 2 weeks. Even low-dose radiation (eg, 10 Gy) can lead to long-term and sometimes permanent remission.
5. Cytostatics such as cyclophosphamide 200 mg per day are used when steroid and radiation therapy are ineffective.

Differential diagnostics

1. Orbital bacterial cellulitis should be considered when there is severe redness of the anterior orbital tissues. A trial of systemic antibiotics may be required to establish the correct diagnosis.
2. The acute manifestations of endocrine ophthalmopathy may be similar to idiopathic orbital inflammation, but endocrine ophthalmopathy is usually bilateral, whereas idiopathic orbital inflammation is usually unilateral.
3. Systemic diseases such as Wegener's granulomatosis, periarteritis nodosa, Waldenstrom's macroglobulinemia may be accompanied by orbital symptoms similar to idiopathic orbital inflammation.
4. Malignant tumors of the orbit, especially metastatic.
5. Rupture of a dermoid cyst can lead to secondary granulomatous inflammation with pain syndrome.