Orbital ultrasonography in the diagnosis of neoplastic extraocular muscle enlargement.

Neoplastic infiltration of the extraocular muscle (EOM) is a rare condition which can pose a diagnostic dilemma due to its rarity and overlapping ultrasonographic features with orbital myositis. The ultrasonographic features of neoplastic enlargement of EOM have not been systematically studied and previously have been described in only a few case reports. Orbital ultrasonography, in conjunction with the pattern of ocular misalignment, was assessed for its potential role in identifying patients with neoplastic EOM enlargement. Retrospective chart review of patients with neoplasm and myositis. The clinical features of 8 patients with neoplastic infiltration of the EOM were compared to 15 patients with myositis. In the neoplastic group the width of the EOM was (10.5 mm) almost twice the normal width of the muscle with myositis (p < 0.001). All the muscles in the neoplastic category were low to medium reflective. Paretic deviation was seen in 4/8(50%), purely restrictive in 2/8 (25%) and combined pattern in 2/8 (25%) were noted. In the myositis group the average EOM enlargement was 5.8 mm and all muscles showed low reflectivity. Although ultrasonographic features overlapped between the 2 groups paretic deviations were more common in the neoplastic group versus the myositis group (50% versus 7%). Neoplastic muscle enlargement tends to be larger with paretic deviations of ocular motility seen clinically. These findings in a patient with EOM enlargement should raise the suspicion of neoplasm as the etiology and further work up should be considered.

Occult thyroid eye disease in patients with unexplained ocular misalignment identified by standardized orbital echography.

PURPOSE: To describe the clinical presentation, orbital echography (OE) findings, and neuroimaging results of patients with chronic unexplained ocular misalignment, which includes patients with clinically occult thyroid eye disease (TED) that is identifiable through a characteristic OE appearance. DESIGN: Retrospective observational case series. METHODS: Seventy-eight patients with chronic ocular misalignment suspected of TED because of a history of systemic thyroid disease, proptosis, dysmotility, positive forced ductions, or eyelid retraction or lag were categorized as TED positive, negative, and indeterminate with the use of standardized OE. Demographic, clinical, OE, computed tomography, and magnetic resonance imaging information was collected. Analyses determined the prevalence of TED and differences between TED positive, negative, and indeterminate groups. RESULTS: Fifty-five percent of the findings were suspicious for and most consistent with TED (TED positive); 26% of the findings were TED negative, and 19% of the findings were TED indeterminate. Of 30 patients with newly diagnosed TED by OE, 70% had no lid retraction, and 20% had no other findings of TED. The inferior rectus followed by the superior rectus/levator complex, medial rectus, and lateral rectus muscles were the most frequently involved muscles. Neuroimaging that was performed in only 26 of 78 patients (33%) did not appear to yield additional diagnostic information. CONCLUSION: TED is a potential cause of chronic unexplained ocular misalignment in a substantial proportion of patients. These patients frequently present in an occult fashion without other clinical findings that are typical of TED. In these patients, a diagnosis of TED by OE can reduce further costly evaluation. OE appears to have significant clinical usefulness in the diagnosis of TED in patients with unexplained ocular misalignment.