Lens disorders 1

Lens disorders

Marwan S.Salman M.D Ass.Professor of Ophthalmology Tikrit university , college of medicine

Anatomy of crystalline lens

Crystalline Lens Of Eye Transparent, biconvex, avascular structure enclosed by a capsule(basement membrane secreted by lens epithelium) Approx. diameter is 10mm Lens measures approximately 10 mm in diameter and 4 mm thick Suspended by zonular fibres Parts Of Lens Capsule Cortex Nucleus Anatomy Of Lens CAPSULE ANT CAPSULE Basement membrane of ant lens epithelium POST CAPSULE Basement membrane of cell lens that have nuclei near lens equator Thickest basement membrane in the body


WHAT IS A CATARACT ?Any opacity in the lens or it’s capsule whether developmental or acquired is called cataractORLoss of transparency of crystalline lens is cataractAging ChangesNuclear changes (nuclear sclerosis)Hardening of nucleus starts as early as 20 years of age.Increase in insoluble proteinsCholesterol level increases while phospholipid level decreases

Symptoms Of Cataracts

Hazy, fuzzy or blurred vision Double vision Frequent changes in spectacle prescriptions Feeling of having a film over the eye Colours appear dull Glare in bright daylight, and at night from bright light sources

Persone with cataract

Acquired Cataract


Senile cataract Presenile cataract Traumatic cataract Secondary cataract Age Related Cataract

Morphological classification

Anterior subcapsular Posterior subcapsular Nuclear Cortical Christmas tree

SUBCAPSULAR CATARACT

Anterior subcapsular cataract Lies directly under lens capsule & there is associated fibrous metaplasia of anterior epithelium of the Lens Posterior subcapsular cataract Lies just in front of posterior capsule Associated with posterior migration of epithelial cells of lens Patient troubled by headlights & bright sunlight Near vision is diminished more than distance Vision

NUCLEAR CATARACT

CORTICAL CATARACT

Nuclear sclerosis grading

Nuclear cataract

Posterior subcapsular cataract Abnormal red reflex

Hypermature cataract Morgagnion cataract

Classification According To Maturity

Immature Mature Hypermature Morgagnian IMMATURE CATARACT Lens is partially opaque MATURE CATARACTLens is completely opaque

HISTORY

Age of Onset Decreased Vision Painless, Effecting daily routine activity? Trauma Any Ophthalmological Problems Drugs Intake Exposure to Radiations Systemic Diseases H.T DM etc. Skin disease, joint pains, etc. Family History

EXAMINATION

GENERAL PHYSICAL EXAMINATION SYSTEMIC EXAMINATION OCULAR EXAMINATION Visual Acuity Adnexa Iris Conjunctiva Cornea Anterior Chamber Pupil Lens Vitrous Retina

INVESTIGATIONS

Blood Glucose ECG Chest x-rays (PA view) Blood Complete Picture Any specific relevant investigation (if indicated)

OPTIMAL POST OP. REFRACTION

SURGICAL TECHNIQUES

ICCE ECCE ECCE with posterior chamber IOL implant Phacoemulcification

CONGENITAL CATARACT

An opacity in the crystalline lens, present at the time of birth or appears with in first three months of life Occurs in about 3:10,000 live births 2/3 are bilateral Most common cause is genetic mutation, usually autosomal dominant (A.D)

Congenital cataract

AETIOLOGY

AETIOLOGY

Microphthalmia Aniridia Coloboma

AETIOLOGY


CHROMOSOMAL ABNORMALITIES 03%Down’s syndromeTurner syndromeTrisomy 13 & 18BIRTH TRAUMA 02%SKELETAL SYNDROMESHallermann-Streiff-Francois syndromeNance-Horan syndrome

Clinical Features

Symptoms Decreased Vision Glare Signs Leukokoria Nystagmus Strabismus Amblyopia Microphthlamos

Morphological classification

NUCLEAR CATARACT LAMELLAR (ZONULAR) CATARACT CORONARY CATARACT SUTURAL (STELLATE) CATARACT ANTERIOR POLAR CATARACT

CLINICAL FEATURES

CLINICAL EVALUATION


Torch examination Examination under Anesthesia Ophthalmoscopy direct / indirect Associated ocular pathology Corneal clouding Microphthalmos Glaucoma Persistent anterior fetal vasculature Chorioretinitis Rubella retinopathy Foveal or optic nerve hypoplasia PAEDIATRIC CONSULTATION Dysmorphic features or suspicion of associated systemic diseases

LABORATORY INVESTIGATIONS

TORCH screening Blood Complete picture Blood Glucose levels Serum calcium and phosphorus Urine:for reducing substances after drinking milk (glactosaemia) and chromatography for amino acids (lowe syndrome ) . Chromosome analysis Refer for syspicious other systemic diseases

VISUAL FUNCTION EVALUATION

DIFFERENTIAL DIAGNOSIS



LEUKOCORIA Retinoblastoma Retinopathy of Prematurity Persistent Hyperplastic Primary Vitreous Retrolental Fibroplasia Toxocariasis Toxoplasmosis Incontinentia pigmenti Retinal Detachment Cytomegalovirus Retinitis RETINOBLASTOMA RETINAL DETACHMENT WITH A MITTENDORF SPOT PERSISTENT HYPERPLASTIC PRIMARY VITREOUS TOXOPLASMOSIS RETROLENTAL FIBROPLASIA

PROGNOSIS

Preoperative assessment for cataract surgery


Visual symptoms blur/glare ,distortion, color perception ,second sight POM history of amblyopia, stabismus ,previous surgery e.g refractive surgery, trauma ,concorrent eye disease. PMH DM, HT,COAD, anasthetic history if GA considered . SH occupation and daily task . DH warfarin , antiplatelet agent,topical medication . VA Cover/uncover test. PUPILS check RAPD , adequate dilitation. Cataract morphology ,density, maturity Others factors globe (deep set,small /large), lids (blepharitis ,ectropion, entropion), nasolacrimal (mucocele), Cornea (scarring ,guttata) Anterior champer depth


IOP IRIS ( PXS,iridodonesis,posterior synchiae, inducable mydrasis . Lens (PXS, phacodonesis, sublxation,type of cataract ) Optic disc e.g glaucoma, neuropathy, macula (AMD ),fundus . Complications Intra operative : Posterior capsule rupture without vitreous loss (2%) Posterior capsule rupture with vitrous loss(1%) Anterior capsule problem Zonular dehiscence. Loss of nuclear fragment posteriorly 0.3% Choroidal haemorrhage 0.1% Post operative early corneal odema Elevated IOP


Increase anterior inflammation Wound leake Iris prolapse Endophthalmitis Post operative late Posterior capsule opacification Cystoid macular odema Retinal detachement Corneal decompensation

Ectopia lentis

Displacement of the lens from its normal position . Te lens may be completely dislocated,rendering the pupil aphakic (luxated) , or partially displaced still remaining in the pupillary area (subluxated) ,ectopia lentis may be herediatory or acquired . Acquired causes included trauma, a large eye (i.e high myopia , buphthalmos), anterior uveal tumor and hypermature cataract . Without systemic association 1- familial ectopia lentis 2- ectopia lentis et pupillae

Ectopia lentis et pupillae

With systemic association 1- marfan syndrome 2- weill - marchesani syndrome 3-homocystineuria 4- hyperlysinaemia 5-stickler- syndrome


Mangement The main complication of ectopia lentis are a-refractive error (lenticular myopia ) b-optical distortion due to astigmatism c-glaucoma and rarely d- lens induse uveitis 1- spectacele correction may correct astigmtism induced by tilt or the edge effect in the eye with mild subluxation aphakic correction may also afford good visual result if significant portion of visual axis is aphakic in the undilated state . 2-Surgical removal of lens is indicated for cataract , lens induced glaucoma ,uveitis or endothelial touch