文档介绍：cataract
福建医科大学附属第一医院
福建省眼科研究所
徐国兴
What is a cataract?
A cataract is an opacity(or cloudy changes)
of the lens that can cause vision problems.
任何先天性或后天性因素引起的晶状体
混浊使其透明性下降,称为白内障。
LENS
The lens is surrounded by a thick lens capsule which is the basement membrane of the lens epithelial cells.
Epithelial cells at the lens equator continue to be produced throughout life,so that older lens fibers pressed into a central nucleus; younger fibers around the nucleus make up the cortex.
晶状体囊是一层包绕整个晶状体的透明囊状基底膜。位于晶状体赤道部囊下的上皮细胞终生增殖,不断形成晶状体纤维,将旧的纤维挤向中心的核,核外较新较疏松的纤维构成皮质。
causes
Aging mon
Long-term ultraviolet (UV) light, especially from sunlight
Diabetes or other systemic disease
Past eye infections, injuries or surgery
Smoking
Long-term use of certain medications (such as steroids)
heredity
Pathogenesis
The lens is made mostly of water and protein. The protein is arranged to let light pass through and focus on the retina. Sometimes some of the protein clumps together. This can start to cloud small areas of the lens, blocking some light from reaching the retina and interfering with vision.
晶状体主要由水和蛋白组成。发生白内障的晶状体特征性改变是蛋白之间的交联形成聚合物,使光线散射增强,晶状体透明度下降。
自由基引起的氧化损伤
晶状体上皮细胞氧化损伤——膜蛋白降解——细胞膜通透性增加——晶状体内渗透压增高、肿胀;晶体蛋白之间二硫键形成增多——蛋白交联形成高分子量聚合物——光散射增强,晶状体混浊。
细胞凋亡及其调控
normal Vs. cloudy lens
Clinical Findings
Symptoms
Blurring or dimness of vision 视力下降
colors appear faded 色觉改变
Sensitivity to light and glare 眩光
Double or multiple vision 复视或多视
Change in refraction 屈光改变