1. Lens diseases Wen Xu Eye Center, 2nd Affiliated Hospital Zhejiang University

2. The most common cause of painless, progressive loss of vision today is

3. Cataract

4. Anatomy of the lens  Location posterior to iris anterior to vitreous  Shape biconvex  Structure lens capsule lens cortex lens nucleus

5. Physiology of the lens  No vessel, nerve and transparent.  Derive nutrients from the aqueous humor  Significant refractive medium  Accommodative function  No immediate relation with adjacent tissues  Complex metabolism  Simple disorders: transparency and location change

6. Cataract  Definition: opacification of the lens  epidemiology: clinical cataract corrected vision<0.5

7. Cataract Mechanism: many factors lens capsular damage osmosis increase,loss of protective screen,metabolic disorders protein degeneration, cell apoptosis lens opacify cataract

8. Cataract Classification:  by cause: congenital, senile(age-related), complicated, metabolitic, drug-induced, toxic, traumatic, secondary  by age:congenital, acquired  by location: cortical, nuclear, subcapsular  by shape: dot-like, coronary, lamellar  by degree: immature, intumescent, mature, hypermature

9. Cataract Symptoms:  decreased vision: most obvious and important  decreased contrast sensitity  refractive error: myopia,astigmatism  monocular diplopia or multiple vision  glare: scattered light rays  poor color discrimination:blue spectrum

10. Cataract Signs: The lens is best examined with the pupil dilated. A magnified view of the lens can be obtained with a slit-lamp or by using the direct ophthalmoscope with a high plus (10+) setting

11. Cataract Grade’s standards of nuclear hardness: Ⅰ transparent,no nucleus,soft Ⅱ yellow-white or yellow,soft Ⅲ dark yellow,moderate hard Ⅳ brown or amber, hard Ⅴ brown or black,extremely hard

12. (I) Age-related cataract Description: the most common type, most patients are beyond their 50’s. The incidence goes up with aging. It is the first rank of ophthalmic diseases leading to blindness Risk factors: Many factors are involved include age, occupation, sex, ultraviolet radiation, diabetes, hypertension, positive family history, nutritious condition

13. (i) Cortical Cataract  The most common type  Four stages : (1) incipient stage (2) intumescent stage or immature stage (3) mature stage (4) hypermature stage

14. 1. incipient stage Features: a 、 cuneiform ( 楔形 ['kjun ɪ ə,f ɔ rm]) opacity b 、 lamellar seperate c 、 vacuole d 、 cracks e 、 no vision damage Tests: a 、 slit-lamp b 、 transillumination

16. 2. intumescent stage or immature stage Features: a 、 more serious opacity b 、 larger volume and more shallow anterior chamber c 、 iris shadow d 、 obvious vision decrease e 、 myopia Tests: a 、 slit-lamp b 、 oblique illumination Matter needs attention: angle-closure glaucoma

19. 3. mature stage Features: a 、 complete opacity, milky white, iris shadow disappear b 、 volumn and anterior chamber regain normal c 、 vision: LP or HM before the eye Tests: a 、 slit-lamp b 、 flashlight

21. 4. hypermature stage Features: a 、 smaller volumn,wrinkled lens capsule,claybank and fallen nucleus (Morgagnian cataract),superior of anterior chamber deepens while inferior is the opposite,ridodonesis. b 、 laceration of lens capsule,lens luxation. c 、 phacoanaphylactic uveitis,phacolytic glaucoma

24. (ii) Nuclear Cataract Features: a 、 start earlier,generally on 40’s,slowly progressive, not likely to be mature. b 、 nuclear opacity: start by embryonic nucleus. c 、 vision: no vision damage early on, myopia Tests: slit-lamp 、 transillumination 、 oblique illumination

27. (iii) Subcapsular Cataract Features: a 、 start earlier b 、 posterior subcapsular cataract: cause obvious vision defect early on c 、 cupuliform( 杯状 ) opacity of posterior pole

29. (II) Congenital Cataract Features: present at birth or appear shortly thereafter; unilateral or bilateral; may be alone or associated with other ocular or systemic congenital abnomalities Etiology: (1) hereditary factors(chromosome,gene) (2) environmental factors (matrix disease) when pregnance <3 m: virus infection; drugs,metabolic diseases (3) undetermined causes

30. Classification According to location, form and degree  anterior polar cataract  posterior polar cataract  perinuclear cataract  coronary cataract  punctate cataract  total cataract  membrane cataract  nuclear cataract

31. Congenital cataract

32. Anterior polar cataract

33. Posterior polar cataract

34. Perinuclear cataract

35. Coronary cataract

36. Punctate cataract

37. Total cataract

38. Membrane cataract

39. Nuclear cataract

40. (III) complicated cataract Features: ocular inflammation or degenerative disorders→ nutritious or metabolic defect → lens opacity Common causes: corneal ulcer, glaucoma, uveitis,retinal detachment, retinitis pigmentosa, intraocular tumor,high myopia, etc.

41. Clinical findings: 1. primary disease changes 2. cataract Treatment: 1. treat the primary disease. 2.do the surgery after 3 m of inflammation control

42. (IV) Metabolic cataract  Diabetic cataract  Galactose cataract: lack of enzyme  Tetany cataract: low blood calcium  Wilson’s disease (Hepatolenticular Degeneration): KF ring, sunflower-shaped opacity,copper.

43. 1. Diabetic cataract  Mechanism: blood sugar↑ →sugar in the lens↑ → change into sorbitol→plasma osmotic pressure↑ →absorb water→fibers swellen and degenerate→lens opacity

44.  classification: (1) real diabetic cataract (2) age-related cataract of diabetic patients  Clinical findings: (1) the first type: teenagers,bilateral,rapidly progressive,eading to total cataract,combined with refractive changes according to blood sugar (2) the second type: high incidence,start earlier, fast progressive, easy to be mature,similar with senile cortical cataract

45.  Treatment: (1) positively treat diabetes,control blood sugar (2) do the surgery if permitted (3) positively postoperational infection and bleeding prevention

46. (V) Drug-induced and toxic cataract  Corticosteroid cataract  Chlorpromazine cataract  Miotic cataract  Trinitrotoluence cataract  Metals

47. Trinitrotoluence cataract

48. (VI) Traumatic cataract  Classification: Contusive cataract Penetrating cataract Chemical injuries cataract Radiation cataract Electric cataract  Treatment: observation or surgery

49. (VII) Secondary cataract  Definitions: opacification of the posterior capsule due to partially absorbed traumatic cataract or following extracapsular cataract extraction (posterior capsular opacification). It is the most common complication of cataract surgery  Clinical findings: vision decrease after cataract surgery; Elschnig’s pearls

50.  It is a significant problem in almost all pediatric patients unless the posterior capsule and anterior vitreous are removed at the time of surgery. Up to 30%-50% of all adult patients develop an opaque secondary membrane after cataract surgery  Treatment: neodymium:YAG capsulotomy

52. Treatment of cataract  There are many kinds of medicines,but none has certain positive effect  Surgery is the chief method

53. Surgical treatment  Timing of the surgery: a 、 mature stage→visual acuity b 、 consider the surgery conditions and the subjective requirements of patients

54.  Preoperative Examination & preparation  O cular: VA,LP,color vision,anterior segment,fundus,IOP,SLE,EKG,VEP,ultrasonic,etc.  System:BP,blood sugar,etc.  Corneal curvature,the axial length of the eye.calculate the diopter of the IOL  Endothelial cell acount (specular microscopy)  Wash conjunctival sac and lacrimal canal,dilate the pupil

55. Way of the surgery  Couching( 针拨 ) of lens  Intracapsular cataract extraction (ICCE)  Extracapsular cataract extraction (ECCE)  Phacoemulsification (PHACO) Phacoemulsification (PHACO)  Laseremulsification  Intraocular lens implantation

57. Surgical complications  Complications during the surgery (1)shallow or no anterior chamber (2)intraocular tissue lesion (3)hemorrhage (4)posterior capsular rupture

58.  Postoperational complication (1)hemorrhage (2)high IOP (3)endophthalmitis (4)chronic uveitis (5)posterior capsular opacification (6)corneal astigmatism (7)retinal phototoxicity (8)cystoid macular edema, CME

59.  Postoperational complications of IOL implantation (1)pericorneal fibrous proteins exudation (2)dislocation of IOL (3)secondary glaucoma and decompensation of corneal endothelium (4)diopter inaccuracy of IOL

60. Refractive correction of aphakia  IOLs :Multifocal, Accommodatable  Spectacles  Contact lens  Refractive surgeries: keratophakia, keratomileusis, epikeratophakia

61. Dislocated lens or ectopia lentis  Causes (1) congenital simple dislocation; combined with lens or ocular abnormalities; systemic syndromes (Marfan syndrome, homocystinuria, Marchesani syndrome, Ehlers-Danlos syndrome) (2) traumatic (3) spontaneous

62.  Clinical findings (1) Partial dislocation: the edge of the lens and the zonular fibers holding it in place can be seen in the pupil. It is often complicated by deepen anterior chamber,iridodonesis and vitreous hernia. High myopia and monocular diplopia,or even secondary glaucoma may occur (2) Complete dislocation: include pupil entrapment,dislocated into anterior chamber, dislocated into vitreous cavity,dislocated into subconjunctiva or even extraocular

63.  complications (1)Uveitis (2)Secondary glaucoma (3)Retinal detachment: the most common (4)Corneal opacification

64.  Treatment (1) nonsurgical therapy: If no complications, dislocated lenses are best left untreated. Close conservation and spectacles or contacts may have some value (2) surgical therapy: If uveitis or uncontrollable glaucoma occurs, lens extraction must be done. The technique of choice is limbal or pars plana lensectomy using a motor-driven lens & vitreous cutter

66. Dislocated in anterior chamber

67. Partial dislocation