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June 2006

 
Morning Rounds

The Case That Began With a Dinner Invite
By Jason Leng, BS, Julia Song, MD, and Alice Song, MD
Edited By Thomas A. Oetting, MD
 
 

Kelly Jones* was looking forward to having her favorite aunt and uncle over for dinner when the trouble began. The 45-year-old African- American was busy giving the house a top-to-bottom cleaning when her left eye started to hurt. Having just dusted the ceiling, she assumed that something had gotten in her eye. She tried eye wash, but this brought no relief.

When her relatives arrived later that day, Ms. Jones declined her uncle’s offer of a ride to the ER. In addition to severe pain in the left eye, she was suffering extremely blurry vision and binocular diplopia, but she denied any nausea or vomiting. One month after the pain started, Ms. Jones developed a fever. And after four days of fever, she was finally persuaded to visit the hospital. The ER referred her to our eye clinic to be evaluated for orbital cellulitis.

We Get a Look

Her left eye was red and swollen with pain in extraocular movement (Fig. 1).

On examination, her vision without correction was 20/40 in the right eye and 20/400 in the left. Manifest refraction resulted in no improvement. The maxillary sinus was tender on percussion and she had a 4+ relative afferent pupillary defect in the left eye. An external exam revealed marked proptosis (Fig. 2); Hertel exophthalmometry demonstrated 19.5 millimeters in the right eye vs. 24 mm in the left. When we assessed her extraocular motility, it was full in the right eye but severely limited in the left eye, with –3 on lateral and downward gazes and –4 on upgaze (Fig. 3).

Her IOP was 16 mmHg in the right eye and 23 mmHg in the left. The slit-lamp exam was normal in the right eye, but in the left eye it revealed 3+ conjunctival chemosis, 2+ punctate epithelial erosions on the cornea and a shallow anterior chamber. The iris and lens were normal in the right eye. A dilated fundus exam of the left eye showed significant optic nerve head and macular edema with 3+ macular striae, and venous dilatation (Fig. 4). There were no hemorrhages. A CT scan of the head and sinuses was significant for marked proptosis in the left eye with orbital fat streaking (Fig. 5). The extraocular muscles showed inflammation that also involved the tendons. There was no evidence of sinusitis, abscesses or masses.

What's Your Diagnosis?

What's Your Diagnosis
After seeing Ms. Jones’ red, swollen left eye (1), the ER physician suspected orbital cellulitis. We noted that there was marked proptosis (2) and that extraocular motility of her left eye was severely limited (3).


What's Your Diagnosis (Figure 4, 5, 6)
(4) Dilated fundus exam of Ms. Jones’ left eye. (5) The CT scan helped to rule out orbital cellulitis. (6) After treatment, Ms. Jones’ ocular motility returned to normal—though for a time there was some continued restriction in upgaze.


Our Diagnosis

Ms. Jones was diagnosed with orbital inflammatory pseudotumor. This is an idiopathic, nonspecific, nongranulomatous orbital inflammation that presents with orbital swelling that mimics a mass. There are four subtypes: granulomatous, sclerosing, vasculitic and eosinophilic.1

It affects males and females equally of all races and age ranges, but it occurs most commonly in individuals between 30 and 50 years of age. In most cases it occurs unilaterally, but in children it commonly presents bilaterally (45 percent).2 It comprises about 5 to 8 percent of all orbital lesions and about 16 percent of unilateral proptosis cases in adults.2 Although the mechanism of pathogenesis is still unknown, recent studies suggest a possible role of autoimmunity causing an inflammatory infiltrate to compress tissues. And although classified as benign and self-limiting, it can potentially cause serious ocular damage and vision loss if not treated.



A Diagnosis of Exclusion

Ms. Jones displayed a classic presentation of orbital pseudotumor with painful and restricted ocular motility, redness, proptosis and chemosis. She also had optic disc edema, which can occur secondary to optic nerve compression.

However, other diagnoses share this type of presentation. These include orbital cellulitis, lymphangioma, arteriovenous fistula, orbital foreign body with abscess and, given that she had a history of sickle cell disease, venous thrombosis. Systemic diseases that should be considered include sarcoidosis, Wegener’s granulomatosis and thyroid-related orbitopathy. Arteriovenous fistula was also on the differential diagnosis; however, she denied any ocular trauma.

The presence of fever and painful ocular motility necessitated an evaluation to rule out orbital cellulitis. Because her symptoms were subacute (she had postponed medical care for approximately one month after onset of symptoms), her diagnosis is less suggestive of orbital cellulitis, which usually occurs more rapidly. And her CT scan revealed neither sinusitis, which is commonly associated with orbital cellulitis, nor venous thrombosis. Biopsy, which is the gold standard for diagnosing orbital pseudotumor,3 is rarely performed due to the risks of the procedure.

In practice, orbital pseudotumor is diagnosed after ruling out other more menacing diseases requiring immediate intervention such as orbital cellulitis. In addition to basic blood and metabolic tests, a head CT is very useful in pinpointing the diagnosis. Orbital pseudotumor is limited to the orbit, featuring inflammation of the extraocular muscles with involvement of the tendons. This was clearly seen in Ms. Jones’ case.



Treatment

Ms. Jones was treated with 80 milligrams of oral prednisone daily for four days, and then slowly tapered over a few weeks. The pain, swelling and proptosis in her left eye resolved with her vision returning to 20/20 with correction, and her ocular motility improved (Fig. 6). Recurrence rates of orbital pseudotumor can be high if the steroid is tapered too rapidly. In recurrent and refractory cases, low-dose radiation therapy may be helpful.4,5 For cases refractory to both steroid and radiation therapy, methotrexate may also be an option.6

In summary, pseudotumor is a diagnosis of exclusion. Other causes of proptosis and inflammation, such as infection, should be ruled out. A CT scan is helpful in differentiating pseudotumor from orbital cellulitis. With proper diagnosis and treatment, patients with orbital pseudotumor can do well.

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* Patient name is fictitious.

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1 Mombaerts, I. et al. Surv Ophthalmol 1996;41:66–78.
2 Weber, A. L. et al. Radiol Clin North Am 1999;37:151–168.
3 Kunimito, D. Y. et al. The Wills Eye Manual, 4th ed. (Philadelphia: Lippincott Williams and Wilkins, 2004).
4 Sergott, R. C. et al. Arch Ophthalmol 1981; 99:853–856.
5 Isobe, K. et al. Radiat Med 2004;22:429–431.
6 Smith, J. R. and J. T. Rosenbaum. Br J Ophthalmol 2001;85:1220–1224.

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Dr. Julia Song is assistant professor of glaucoma, Dr. Alice Song is assistant professor of oculoplastics and Dr. Leng completes his medical degree this month; all are at Loma Linda University, Calif.