永存原始玻璃体增生症的临床表现及晶状体后纤维血管膜的病理学特征

Clinical manifestations and pathological characteristics of retrolental membranes secondary to persistent hyperplastic primary vitreous

背景 永存原始玻璃体增生症（PHPV）为儿童的先天性眼部疾病,因为其临床表现无特异性,易误诊为先天性白内障,预后较差.以往对PHPV的临床特点研究较多,但对其组织病理学特点和免疫组织化学染色的特点报道很少. 目的 研究PHPV的临床表现和晶状体后纤维血管膜的组织病理学特点,为其病理机制研究提供依据.方法 采用回顾性系列病例研究方法,收集2005年5月至2014年12月诊治的6例6眼PHPV患者的临床资料,所有患眼均接受先天性白内障针吸联合前部玻璃体切割术,对术中获取的晶状体后纤维血管膜标本进行苏木精-伊红染色和过碘酸希夫染色,分析其组织病理学特点.采用Envision二步法行免疫组织化学染色,检测晶状体后纤维血管膜标本中波形蛋白（Vimentin）、平滑肌肌动蛋白（SMA）、S-100、胶质纤维酸性蛋白（GFAP）、神经元特异性烯醇化酶（NSE）、上皮膜抗原（EMA）、CD34和增生细胞核抗原（PCNA）的表达情况.结果 6例患儿均于出生后发现单眼PHPV,主要临床表现类似于先天性白内障,其中5眼A型超声检查显示患眼眼轴短于对侧健眼,1眼伴眼球震颤、斜视和小角膜.6例患儿均行白内障针吸术联合前部玻璃体切割术,术中可见晶状体后囊膜后有白色纤维血管膜,其中2眼的纤维血管膜与玻璃体内纤维束相连.晶状体后囊膜纤维血管膜标本的组织病理学检查显示,纤维血管膜主要由疏松或黏液样结缔组织纤维、毛细血管或小静脉血管组成,有些病例内可见过碘酸希夫阳性染色物质、残留的透明状玻璃体动脉或分化的脂肪细胞.免疫组织化学检测显示,晶状体后囊膜纤维血管膜中可见短梭形或梭形细胞,具有纤维细胞的特点,部分细胞具有肌纤维母细胞的特征,增生活性较低.1例标本中可见纤维血管膜伸入晶状体囊膜内,导致晶状体和睫状体的发育异常.4例患儿随诊6～9年,术后最佳矫正视力（BCVA）分别为0.06、光感、0.05和0.07,眼压正常.结论 PHPV首诊多误诊为先天性白内障,术后BCVA较差.晶状体后纤维血管膜主要是由于原始玻璃体内中胚叶细胞持续增生和透明动脉不能退化所致,纤维血管膜的增生导致晶状体发育异常.

Background Persistent hyperplastic primary vitreous （PHPV） is a congenital eye disease of children,because its clinical manifestations are nonspecific,it is easy to be misdiagnosed as congenital cataract and the prognosis is poor.There has been more researches on PHPV clinical characteristics than its histopathological feature and immunochemistry.Objective This study was to investigate the clinical characteristics of PHPV and the pathological characteristics of retrolental membranes secondary to PHPV.Methods The clinical data of 6 PHPV eyes from 6 patients during May 2005 to December 2014 were retrospectively analyzed.All the PHPV eyes received a combinating procedure of cataract extraction and anterior vitrectomy.The retrolental membranes were collected during surgery for the histopathological examination by hematoxylin ＆amp; eosin staining and periodic acid-Schiff （PAS）staining.Immunochemistry was used to detect the expression of Vimentin,smooth muscle actin （SMA）,S-100,glial fibrillary acidic protein （GFAP）,neuron specific enolase （NSE）,epithelial membrane antigen （EMA）,CD34 and proliferating cell nuclear antigen （PCNA） in the retrolental membranes.Results Monocular PHPV was found in 6 cases since born,with the main clinical manifestation of similar to congenital cataract.The ocular axial was shorter in 5 PHPV eyes than that of the contralateral eye by A-sonography,and 1 eye accompanied by eye nystagmus,strabismus and small cornea.The retrolental membranes were seen during the surgery in all cases,and the white band through the vitreous in 2 eyes.Pathological examination showed that the retrolental membrane was mainly composed of loose or myxoid connective tissue fibers,the capillaries and small veins.PAS positive tissue,residual transparent artery and differentiated adipocytes were exhibited in some specimens.Immunohistochemistry indicated that spindle-shape cells in the retrolental membranes presented the characteristics of mesenchymal cells,and some cells appeared the myofibroblast characteristics with the low proliferation activity.The development of the lens and the ciliary body was abnormal because of the stretching of retrolental membranes into the lens capsule in 1 PHPV eye.The follow-up was performed for 6-9 years in 4 eyes,with the best corrected visual acuity （BCVA） for 0.06,light perception,0.05 and 0.07 respectively.The intraocular pressure was normal in all the eyes.Conclusions PHPV is usually misdiagnosed as congenital cataract and shows a poor postoperative BCVA.PHPV occurs mainly due to an incomplete regression of the embryonic vitreous and hyaloid vasculature and eventual abnormality of lens.