Le Moli Rosario, Pluchino Alessandro, Muscia Vincenzo, Regalbuto Concetto, Luciani Bruno, Squatrito Sebastiano, Vigneri Riccardo
Department of Internal Medicine, Endocrinology, University of Catania, Garibaldi-Nesima Hospital, Catania, Italy.
Eur J Ophthalmol. 2012 May-Jun;22(3):301-8. doi: 10.5301/ejo.5000018.
Both extraocular muscle (EOM) and orbital fat are involved in Graves' orbitopathy (GO) but their enlargement might occur with a different temporal pattern. Two GO subtypes have been described, one with predominant EOM enlargement and the other with prevalent fat tissue involvement. We longitudinally investigated the EOM in patients with GO and their relationship with clinical activity.
By using commercial software with a segmentation technique, we calculated from computed tomography (CT) scan EOM coronal area (CA) and total orbit coronal area (TOA) in 23 control subjects and in 32 patients with GO. The latter were studied both at presentation and 18 months later. Superior, lateral, inferior, and medial EOM areas and TOA were selected by 3 different contiguous CT slices: A, B, and C, chosen at globe pole tangent and 2 and 4 mm backward. The Clinical Activity Score (CAS) was also measured.
Orbital EOM CA/TOA ratio (OM/TOA ratio) after 18 months decreased in most patients with GO, indicating that EOM area decrement contributed significantly to OM/TOA ratio reduction. Clinical Activity Score decrease was significantly correlated to the OM/TOA ratio decrease.
An easy method to measure CA of EOM and orbit allowed us to observe that in most patients with GO the OM/TOA ratio decreases with time, suggesting that macroscopic EOM involvement occurs initially and resolves as the other clinical signs and symptoms of the disease resolve, as indicated by the significant OM/TOA ratio correlation with CAS.
眼外肌（EOM）和眶脂肪均参与格雷夫斯眼眶病（GO），但其增大可能呈现不同的时间模式。已描述了两种GO亚型，一种以眼外肌增大为主，另一种以脂肪组织受累为主。我们纵向研究了GO患者的眼外肌及其与临床活动的关系。
通过使用具有分割技术的商业软件，我们计算了23名对照受试者和32名GO患者的计算机断层扫描（CT）图像上眼外肌冠状面积（CA）和全眶冠状面积（TOA）。对后者在就诊时和18个月后进行了研究。通过3个不同的连续CT切片选择上、外、下和内侧眼外肌面积及TOA：A、B和C，分别在眼球极切线处以及向后2 mm和4 mm处选取。还测量了临床活动评分（CAS）。
18个月后，大多数GO患者的眼眶眼外肌CA/TOA比值（OM/TOA比值）下降，表明眼外肌面积减小对OM/TOA比值降低有显著贡献。临床活动评分降低与OM/TOA比值降低显著相关。
一种测量眼外肌和眼眶CA的简便方法使我们观察到，大多数GO患者的OM/TOA比值随时间下降，这表明眼外肌的宏观受累最初出现，并随着疾病的其他临床体征和症状的缓解而消退，OM/TOA比值与CAS的显著相关性表明了这一点。
