人白内障球结膜微血管的电镜观察

目的 :观察人球结膜微血管的超微结构 ,认识白内障时球结膜微血管的电镜改变 ,为微循环和眼科研究工作提供参考。方法 :观察对象为 5例老年性白内障、1例糖尿病性白内障 ,术前一般状态良好。在白内障手术时取球结膜标本。电镜常规固定、包埋、定位、超薄切片、用电镜观察。结果 :球结膜毛细血管多由 2～ 3个内皮细胞围绕而成。核多为长椭圆形 ,核周缘有轻度凸凹。近腔侧胞浆细胞器较多 ,微丝和微管十分发达。基底膜、周细胞与一般毛细血管相似。 6例白内障球结膜毛细血管的内皮细胞、基底膜、周细胞、管腔都有不同程度的变化。其电镜改变可以分为三类 :( 1)代偿反应性增强改变 :微丝、微管十分发达、核周深凹、胞体突入管腔内、内皮细胞突起穿越基底膜、白细胞穿壁 ;( 2 )可恢复性退变 :线粒体退变、核质周集、胞浆出现空泡、基底膜分层、弥散、小量出血 ;( 3)严重不可恢复性改变 :核质固缩、腔内红细胞融合、血红蛋白溢出弥散、管壁断裂、腔内充满退变、裂解结构 ( 2例 ) ,并通过断裂处出至基底膜外。结论 :白内障病人球结膜微血管的超微结构有程度不等的改变

Ultrasturcture Alterations of Microvessels in Bulbar Conjunctiva in Patients with Cataract

The aim of the study was to evaluate the ultrastructure alterations of the microvessels in bulbar conjunctiva in patients with cataract.Method: Conjunctival biopsy specimens from six patients undergoing cataract surgery were taken,prepared and observed under electron microscopy.Among the six patients,five of them suffered from senile cataract,another one was with diabetic cataract.Results: Three kinds of microvessele alterations were found as following:(1)Compensative reactive changes:the alterations inculated significantly increased microfilaments and microtubels,neutrophilic infiltrate,deep concave nucleus;(2)The reversible degenerative changes:the alteration appeared woolly focal densities of mitochondria,vesiculation of cytoplasma,nucleous chromatin margination and lamination of basement membrane;(3)The irreversible changes:they were the most dramatic which include nuclear pyknosis,erythrocyte fusion,microvessel interruptions,necrotised cells fragmentation which were full of microvessel lumen and appeared outside basement menbran.Conclusion: It has the change of differential degree on ultrastructure alterations of microvesels in bulbar conjunetiva in patiests with cataract.