METHODS: Observational case report.
RESULTS: A 16-year-old girl affected by Noonan syndrome underwent a complete ophthalmological examination showing bilateral proptosis with hypofunction of lateral rectus and superior oblique muscles. Visual acuity, color discrimination and fundus examination were unremarkable. The orbital MRI showed bilateral proptosis and symmetrical enlargement of extraocular muscles, with bellies thickening and tendon sparing. The young patient also complained restrictive hypertrophic cardiomyopathy.
CONCLUSIONS: Proptosis is an uncommon ocular manifestation of Noonan syndrome and its pathophysiology has never been clarified. The MRI evidence of extraocular muscles enlargement associated with hypertrophic cardiomyopathy, led us to hypothesize a common altered pathway beneath these features, more specifically the MAP kinase pathway, since extraocular and cardiac muscles share a mesenchymal embryological origin.
方法:观察性病例报告。
结果:一名患有Noonan综合征的16岁女孩接受了完整的眼科检查,显示双侧眼球突出伴外侧直肌和上斜肌功能减退。视敏度,颜色辨别和眼底检查不明显。眼眶MRI显示双侧眼球突出,眼外肌对称增大,腹部增厚和肌腱保留。年轻患者还抱怨限制性肥厚型心肌病。
结论:下垂是Noonan综合征的一种罕见眼部表现,其病理生理学尚未阐明。与肥厚型心肌病相关的眼外肌增大的MRI证据,引导我们假设在这些特征之下有一个共同的改变的通路,更具体地说是MAP激酶途径,因为眼外和心肌具有间充质胚胎学起源。