Cataract

This lecture explains the general aspects of cataract, its symptoms, types, epidemiology, history, examination, investigations and other related aspects.

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Outline of Lecture
  • 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 cataract OR

    Loss  of transparency  of  crystalline  lens is cataract

  • Aging Changes
     Nuclear changes (nuclear sclerosis)
  • Hardening of nucleus starts as early as 20 years of age.
  • Increase in insoluble proteins
  • Cholesterol 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
  • Acquired Cataract
  • Senile cataract
  • Presenile cataract
  • Traumatic cataract
  • Secondary cataract
  • Age Related Cataract
  • Morphological classification
  • Subcapsular cataract
  • Anterior subcapsular
  • Posterior subcapsular
  • Nuclear
  • Cortical
  • Christmas tree
  • Morphological shapes of cataract
  • 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
  • Exaggeration of normal ageing
  • May lead to temporary  myopia  from  increase  in refractive  index  of  lens so patients may be able to read again without spectacles (second sight of the aged)
  • CORTICAL CATARACT
  • Involves anterior, posterior or equatorial cortex.
  • Opacities start as vacoules or clefts between lens fibers
  • Later they may develop into radial spoke-like opacities
  • CORTICAL CATARACT
  • Christmas tree Cataract
  • Uncommon
  • Striking, polychromatic, needle-like deposits in the deep cortex or nucleus
  • May be solitary or associated with other  opacities
  • AGE RELATED CATARACT
  • Classification According To Maturity
  • Immature
  • Mature
  • Hypermature
  • Morgagnian
  • IMMATURE CATARACT
  • Lens is partially opaque
  • MATURE CATARACT
    Lens is completely opaque
  • EPIDEMIOLOGY
  • Cataract surgery is the most commonly performed surgery in elderly patient
  • Any Age
    • Two peaks
  • HISTORY
  • Age of Onset
  • Decreased Vision
  • Painless,
  • Effecting daily routine?
  • Trauma
  • Any Ophthalmological Problems
  • Drugs Intake
  • Exposure to Radiations
  • Systemic Diseases
  • 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
  • If monocular correction is reqd.
    • In contralateral  dense  cataract or amblyopia
    • best post op refraction is -1DS
  • If binocular correction is reqd
    • difference between the two eyes should          not be more than 3DS.
  • 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)
  • AETIOLOGY
  • IDIOPATHIC                                35%
  • HEREDITARY                                         25%
  • INTRA-UTERINE CAUSES         20%
  • Maternal infections
  • Rubella            40-60%
  • Mumps            10-22%
  • Toxoplasmosis 5%
  • Cytomegalovirus
  • HSV
  • Varicella
  • Malnutrition
  • Prematurity
  • Drug induced
  • AETIOLOGY
  • INBORN ERRORS OF METABOLISM              10%
  • Lowe syndrome
  • Galactosemia
  • Mannasidosis
  • Hypoparathyroidism
  • Fabry disease
  • Hypo/hyper glycemia
  • ASSOCIATED WITH OCULAR ANOMALIES   05%
  • Microphthalmia
  • Aniridia
  • Coloboma
  • AETIOLOGY
  • CHROMOSOMAL ABNORMALITIES    03%
  • Down’s syndrome
  • Turner syndrome
  • Trisomy 13 & 18
  • BIRTH TRAUMA      02%
  • SKELETAL SYNDROMES
  • Hallermann-Streiff-Francois syndrome
  • Nance-Horan syndrome
  • Clinical Features
  • Symptoms
  • Signs
    • Leukokoria
    • Nystagmus
    • Strabismus
    • Amblyopia
    • Microphthlamos
  • NUCLEAR CATARACT
  • LAMELLAR (ZONULAR) CATARACT
  • CORONARY CATARACT
  • SUTURAL (STELLATE) CATARACT
  • Sutural cataract
  • ANTERIOR POLAR CATARACT
  • CLINICAL FEATURES
  • White pupillary reflex
  • Poor Visual Acuity
  • Nystagmus
  • CLINICAL EVALUATION
  • Purpose:    To know:
  • Cataract density
  • Type of cataract
  • Condition of retina and optic nerve
  • Any associated ocular anomaly
  • Steps:       
  • 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:
  • Routine examination
  • Reducing sugars
  • VISUAL FUNCTION EVALUATION
  • Visual Acuity
  • Follows light or not
  • Colour targets
  • Reaction to occlusion
  • Pupillary Reflexes
  • Fixation Reflex 
  • Visual Evoked Potentials(VEP)
  • VISUAL FUNCTION EVALUATION
  • Visual Acuity
  • Follows light or not
  • Colour targets
  • Reaction to occlusion
  • Pupillary Reflexes
  • Fixation Reflex 
  • Visual Evoked Responses (VER)
  • 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
  • Visual morbidity may result from deprivation amblyopia, refractive amblyopia, glaucoma        (10% post surgical removal), squint, secondary cataract  and retinal detachment
  • Mental retardation, deafness, kidney disease, heart disease, and metabolic disorders may be part of the presentation