先天性上睑下垂发病机制的研究进展

Research Progress in Pathogenesis of Congenital Ptosis

先天性上睑下垂是一种较常见的先天性眼病,是人群中上睑下垂最常见的原因。在平视前方时,上睑覆盖角膜上缘0.5~2.0 mm,若上睑覆盖角膜上方超过2 mm即可诊断为上睑下垂,主要是由于提上睑肌发育不全或支配它的动眼神经功能不全所致,主要表现为单眼或双眼上睑提起困难,睑裂狭小,发生在双侧者比单侧者多见。对于有些患者,下垂的上睑可以遮盖部分视轴导致弱视的发生。对于该病的确切致病因素迄今尚不明确。该文就近年来有关先天性上睑下垂在遗传学、组织病理学与弱视发生关系等方面的研究进展予以综述。

Congenital ptosis is a common genetic eye disease and is by far the most common cause of blepharoptosis.The normal upper lid is located 0.5 to 2.0 mm over the upper corneal limbus when looking straight forward.If it is below this level,or if a difference is noted between the two eyes,the patient is described as having blepharoptosis.It is generally believed that the reasons for droopy eyelid is related to the weakened levator muscle contraction,or the governing oculomotor dysfunction,which can be unilateral or bilateral（more often seen） ptosis.In many cases,ptosis can impinge upon the visual axis and cause amblyopia.But its exact pathogenic factors remain unclear.Recent contributions to the literature on the genetics,histopathology,and the relationship between congenital ptosis and amblyopia are reviewed here.