ABSTRACT
PURPOSE: To perform and compare differential diagnosis of patients with thyroid-associated myopathy, idiopathic orbital myositis and normal controls based on orbital computed tomography. Orbital fat and extraocular muscle densities were quantified using Hounsfield Unit (HU) and their characteristics were compared and analyzed. METHODS: From February 2005 to January 2013, orbital computed tomography was performed on 90 eyes of 47 thyroid-associated myopathy patients, 18 eyes of 14 idiopathic orbital myositis patients and 280 eyes of 140 normal subjects. The average values of orbital fat and extraocular muscle densities were measured and compared using HU. The density differences between the patients with thyroid-associated myopathy and the normal group were analyzed by age, clinical activity score, ocular protrusion and disease duration. RESULTS: In the thyroid-associated myopathy group, orbital fat and extraocular muscle densities were -87.8 +/- 12.5 HU and 48.7 +/- 7.1 HU, respectively. In the idiopathic orbital myositis group, the orbital fat and extraocular muscle densities were 79.9 +/- 9.9 HU and 49.2 +/- 9.1 HU, respectively. There was a statistically significant lower result of orbital fat in the thyroid-associated myopathy group (p = 0.002), however, the extraocular muscle density did not show a statistically significant difference (p = 0.775). The orbital fat and extraocular muscle densities of the normal group were -79.0 +/- 11.2 HU and 54.3 +/- 6.3 HU, respectively. There were significantly lower results in both orbital fat and extraocular muscle densities in the thyroid-associated myopathy group than normal group (p = 0.000). In active cases and those accompanied by ocular protrusion, there was no significant difference in orbital fat density (p = 0.345 and p = 0.952, respectively), while extraocular muscle density significantly decreased (p = 0.007 and p = 0.003, respectively). CONCLUSIONS: A difference between the orbital fat and extraocular muscle densities in thyroid-associated myopathy and idiopathic orbital myositis could be quantitatively found using HU and orbital computed tomography.
Subject(s)
Humans , Diagnosis, Differential , Muscles , Muscular Diseases , Orbit , Orbital MyositisABSTRACT
PURPOSE: To investigate the clinical characteristics and treatment methods for pediatric thyroid-associated orbitopathy in pediatric patients with thyroid disorders. METHODS: To determine the prevalence and clinical characteristics of pediatric thyroid-associated orbitopathy, we retrospectively analyzed the medical records of 34 patients admitted to the Pediatrics Department of our institution between September 2010 and September 2012. The patients had been diagnosed with autoimmune thyroid disorder and were admitted for treatment of thyroid-associated orbitopathy. RESULTS: In the 24.1 months of follow-up observation, 14 patients were diagnosed with Graves' disease (41.2%) and 20 patients with Hashimoto's thyroiditis (58.8%). Of the 34 patients, 15 (44.1%) developed eye symptoms. Among the eye symptoms, lid swelling was the most prevalent in 41.2% of patients, followed by eyelid retraction in 23.5%, lid lag in 17.6%, conjunctival injection in 14.7%, proptosis in 8.8%, and extraocular muscle hypertrophy in 17.6%. Severe impairment of visual acuity, visual field, and ocular motility were not observed in our study. Although eyelid surgery was performed in 3 cases, most patients were treated conservatively. CONCLUSIONS: Pediatric thyroid-associated orbitopathy was frequently observed in patients with Graves' disease and Hashimoto's thyroiditis. Compared to adults, children showed milder disease manifestation and progression, and the disease could be managed with conservative treatment.