眼科学课件白内障

cataract 福建医科大学附属第一医院 福建省眼科研究所 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 are compressed 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 most common 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 Eye Exam Vision acuity test Slit lamp Ophthalmoscope In most cases, eye drops are used to dilate (widen) pupils before the exam. Tonometry Slit lamp classification 判断晶状体混浊范围和程度 将瞳孔充分散大，采用裂隙灯和后照法，区别晶状体混浊的类型 核性（N）、皮质性（C）、后囊下（P）、核的颜色（NC） 晶状体核硬度分级标准 （据 NC） 度：透明，无核，软性； 度：核呈黄白色或黄色，软核； 度：核呈深黄色，中等硬度核； 度：核呈棕色或琥珀色，硬核； 度：核呈棕褐色或黑色，极硬核。 Age-related cataract 年龄相关性白内障是最为常见的白 内障类型，多见于50岁以上的中、 老年人，随年龄增加其发病率升高 There are three major types of cataract that are named depending on the location within the lens that is most affected. These are cortical, nuclear and posterior subcapsular. A given lens may have components of all three types of cataract. 根据晶状体开始出现混浊的部位，老年性白内 障分为3种类型：皮质性、核性及后囊下白内障 。一个晶状体可能同时发生这3型白内障。 Cortical cataract v the most common type of age-related cataract v four stages as follows: Incipient stage 初发期 Cortical changes may begin as small peripheral water clefts Radical pattern opacity 皮质中空泡和水隙形成 放射状混浊 检眼镜检查可见红光反射中放射状或片状阴影 早期较周边的混浊并不影响视力，病程发展慢 Intumescent stage 肿胀期 The lens takes up water, it becomes intumescent. Anterior chamber gets shallow 混浊加重，皮质吸水肿胀，晶状体体积增大 前房变浅，有闭角型青光眼体质者可诱发青光眼急性发 作。 斜照法检查虹膜投影现象 视力明显下降，眼底难以窥清。 Mature stage 成熟期 Liquid escapes and the lens shrinks The lens protein is totally opaque 晶体内水分溢出，肿胀消退，体积变小 晶体完全混浊，呈乳白色 视力降至手动或光感，眼底不能窥入。 Hypermature Stage 过熟期 A long-standing or very mature cataract may undergo liquefaction of the lens cortex. This liquid may escape through the intact capsule,leaving a shrunken lens with a wrinkled capsule. 在过度成熟的白内障，晶状体皮质液化。囊内水分可溢 出、肿胀消退，体积变小，囊膜发生皱缩。 The dark brown, mature nucleus which sinks inferiorly in the fluid filled capsular sac due to the forces of gravity. is called a Morgagnian cataract. 过熟期，棕黄色的晶状体核在囊内因重力而下沉，称 为Morgagnian白内障。 核下沉可使患者视力突然提高。 This slide shows a lens that has been removed at surgery. Nuclear cataract Early onset (after middle age) The earliest symptom may be improved near vision without glasses (“second sight”) Other symptoms may include poor hue discrimination or monocular diplopia. 起病早，一般中年后开始 早期症状可能是近视力改善（称为“二次视力”），这 是由于白内障初期晶状体核屈光指数增加而产生近视所 致 其他症状可能包括颜色分辨力下降及单眼复视。 Posterior subcapsular cataract Located in the cortex near the central posterior capsule It tends to cause visual symptoms earlier in their development owing to involvement of the visual axis. Common symptoms include glare and reduced vision under bright lighting conditions. 位于后囊下浅皮质层 混浊区位于视轴上，所以早期即可出现视力障碍。 一般症状包括眩光、强光下视力下降。 Congenital Cataract vPresent at birth or appear shortly thereafter vThese cataracts may show many different patterns. The opacity may be confined to the area of the embryonic or fetal nucleus with clear cortex surrounding this. v于出生时或于生后短时间内即出现，形态学表 现各异。混浊可能限于胎儿核周围。 Etiology 病因学 Intra-uterine 宫内因素 vvirus infection: 风疹病毒、巨细胞病毒等感染 vMaternal ingestion of Thalidomide, steroids, 孕期服用某些药物 . Hereditary v autosomal dominant 常染色体显性遗传多见 v recessive；X-linked 隐性和伴性遗传 - Treatment Avoidance of amblyopia Dense, central,larger than 2 mm in diameter congenital cataracts require surgery on an urgent basis. 视觉正常发育受影响，易产生形觉剥夺性弱视 位于中央且程度严重直径超过2mm 则需尽早手 术 Complicated cataract 并发性白内障 Develop as a direct effect of eye diseases upon the physiology of the lens,such as ： glaucoma, iritis, 虹膜炎 eye tumors , retinitis pigmentosa, 视网膜色素变性 retinal detachment. Traumatic cataract 外伤性白内障 Concussion 钝锉伤 Penetrating 穿通伤 Electric shock 电击伤 Radiation 辐射伤 Cataract associated with systemic disease 合并全身性疾病 1. Diabetic cataract -Senile cataract is accelerated 合并老年性白内障 -True diabetic cataract: 真性糖尿病性白内障 2. Galactose cataract 半乳糖性白内障 3 tetany cataract 手足搐搦性白内障 , Drug-induced /toxic cataract 药物或中毒性白内障 Steroids: 糖皮腩激素全身较局部使用发生率高 Chlorpromazine: 氯丙嗪 Metals: 金属（铜、铁、汞等） Miotics: 缩瞳剂 Trinitrotoluence 三硝基甲苯 After Cataract 后发性白内障 Opacifacation of the posterior capsule due to partially absorbed traumatic cataract or following extracapsular cataract extraction. Persistent subcapsular lens epithelium may favor regeneration of lens fibers. 晶状体外伤后或白内障囊外摘出（包括超声乳化）手术 后，残留的皮质或晶状体上皮细胞增生，形成混浊。 Cataract Treatment Surgery is the only way to remove the cataract. However, if symptoms from a cataract are mild, a change of glasses may be all that is needed for you to function more comfortably. Cataract surgery should be considered when cataracts cause enough loss of vision to interfere with daily activities. 白内障手术 ECCE+IOL Extracapsular cataract extraction is a preferred method of cataract surgery It preserves the posterior portion of the lens capsule Posterior chamber IOL can be implanted in the capsular sac 白内障囊外摘出术是目前主导的白内障手术， 将混浊的晶状体核和皮质摘出而保留后囊膜 后房型人工晶体得以植入晶状体囊内 Intraocular Lens An IOL is a tiny, transparent, convex lens made of polymer which is inserted in the eye during surgery. 人工晶体是一种人工制造体积微小、透明的凸 透镜，材料为高分子聚合物，具有良好的光学 物理性能和组织相容性 IOL 可折式 6mm Foldable IOL Anterior chamber type Posterior chamber type Advantages of IOL Since the lens is placed inside the eye, the patient need not wear glasses for distant vision. 无需戴镜 Images are clear and of the same dimension without distortion. 物像清晰，放大倍率小 Full vision is obtained soon after surgery. 术后迅速恢复视力 Phacoemulsification Phacoemulsification or phaco refers to ultra-sonic vibration which dissolves the hard nucleus such that the nuclear material and cortex can be aspired through an incision of approximately 3mm. it is the key to advanced , small-incision cataract surgery. 超声乳化白内障吸除术是应用超声能量将混浊晶体核和 皮质乳化后吸除，保留晶状体后囊 手术切口小，时间短。 Complications 手术并发症 posterior capsule opacification :后囊下混浊最常见 cystoid macular edema 黄斑囊样水肿 glaucoma, 青光眼 hyphema, 眼前房出血 ptosis, 上睑下垂 infection, 眼内炎 最严重 retinal detachment 视网膜脱离 lens dislocation 人工晶体位置异常 After-cataract treatment Unlike a cataract, an after-cataract is treated with a technique called laser capsulotomy. 后发性白内障的治疗不同于其他类型白内障， 激光囊膜切开是有效的方法。 The neodymium: YAG laser provides a noninvasive method for discission of the posterior capsule. Pulses of laser energy creat a small