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Lens Disease. China Medical University NO.4 Affiliated hospital Ophthalmology; Ophthalmology hospital of China Medical University. Introduction. Lens disease: Change of transparency cataract Position and morphological abnormality dislocation malformation. Basic knowledge. Anatomy.
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Lens Disease China Medical University NO.4 Affiliated hospital Ophthalmology; Ophthalmology hospital of China Medical University
Introduction • Lens disease: • Change of transparency • cataract • Position and morphological abnormality • dislocation • malformation
Anatomy • Equator • Anterior capsule • Posterior capsule • Diameter:9-10mm • Thickness:4-5mm • Lens zonule
Anatomy • Capsule: integrity—maintain transparency • Lens epi. — PCO • Lens substance: lens fiber • Nucleus • Cortex
! Function • Refraction • Accommodation • Protection: UV filtration • What is accommodation? • The capability that eyes change refractive condition in order to acquire clear near sight.
What is cataract? • Turbidity of lens • WHO: turbidity of lens + VA<0.5
! Cataract • Cataract is the No. 1 eye disease that causing blind. • 46% blindness is caused by cataract
Etiology • Any factors that change the intraocular environment to affect lens metabolism. • Such as: ageing, mechanical, chemical, operation, inflammation, metabolic • Malformation • Congenital factors
Risk factors • UV • Diarrhea • Malnutrition • Diabetes • Smoking • Drinking alcohol
Classification • On etiology: • Congenital • Senile • Complicated • Metabolic • Drug induced or toxic • Traumatic • After cataract
Classification • On location: • Cortical • Nuclear • Subcapsular • On degree: • Immature • Intumescent • Mature • Hypermature
! Pathogenesis • The common route that causing cataract is the oxidation injury by peroxide free radical. • Apoptosis—hot spot of research
Clinical manifestations • Symptoms: • Progressive vision decrease • Contrast sensitivity decrease • Refraction changes • Diplopia • Glare • Change of color sensation • Visual field defect
contrast test Functionality vision contrast test Positive wave contrast test CSF curve
Vision abnormity Color vision excursion glare visual field loss
Clinical manifestations • Signs: Turbidity of lens
Senile Cataract • Now called Age-related Cataract • Most commonly seen • >50 yrs old • >80 yrs old→100% • Degenerative changes
Classification • Cortical • Nuclear • Subcapsular
Cortical cataract • 4 stages Incipient stage: wedge turbidity
Cortical cataract • 4 stages Intumescent stage (immature): • iris projection • Induce acute angle-closure glaucoma
Cortical cataract • 4 stages Mature stage
Cortical cataract • 4 stages • Hypermature stage: • Morgagni cataract • Phacoanaphylactic uveitis • Phacolytic glaucoma
Subcapsular cataract • Affecting vision early
Congenital cataract • Etiology: • Hereditary • Environmental: • Virus infection • Malnutrition • Radiation • Drug • Systemic disease • VD deficiency
Congenital cataract • Morphology
Congenital cataract • Treatment • observation • Early operation • Amblyopia Treatment
Complicated cataract • Caused by other eye diseases • Corneal ulcer • Glaucoma • Uveitis • Retinal detachment • Retinitis pigmentosa • Intraocular tumor • myopia
Kinds of Complicated cataract Old anterior uveitis Complicated cataract glaucoma Complicated cataract(vogt spot) Pigmentosa eye Silicon oil eye
Metabolic cataract • Caused by systemic metabolic diseases • Diabetic cataract • Galactosemia cataract • Hand-foot-twitch cataract
Drug induced or toxic cataract • Glucocorticosteroid cataract • Chlorpromazine cataract • Miotic cataract • TNT cataract • Metal: copper, iron, mercury, silver, zinc
Traumatic cataract • Contusive • Penetrating • Radiative • Electric
! After cataract • Now usually called PCO (posterior capsular opacification) • Adult: 30-50% • Child: 100% • Pathogenesis: Proliferation, migration & metaplasia of lens epi.
Treatment Drug? NO USE Operation: the only effective therapy ICCE (intracapsular cataract extraction) ECCE (extracapsular cataract extraction) PEA (phacoemulsification) !
ICCE And ECCE ICCE ECCE
Treatment • IOL (intraocular lens) implantation • AC and PC • Hard and foldable
Treatment • IOL (intraocular lens) implantation
Treatment • PEA & F-IOL
Treatment • Correction of aphakia: • Frame glasses • Contact lens • IOL • Laser
Lens Dislocation • Etiology: • Congenital • Marfan syndrome • Traumatic • Spontaneous
Clinical Manifestations • Subluxation • Dislocation
Clinical Manifestations • Complications: • Uveitis • Secondary glaucoma • Retinal detachment • Corneal turbidity
Trends • Photolysis of cataract • Injective IOL • Accommodative IOL