Cataract

Question 1

Definition

Answer 1

Development of any opacity in lens or capsule

Question 2

Etiological classification

Answer 2

Congenital + Developmental
Acquired
Age related (Senile)
Traumatic
Complicated
Systemic diseases
Metabolic diseases
Skin diseases (Syndermatotic)
Myotonic dystrophy
Neurofibromatosis type II
Osseous disesases
Down’s syndrome
Teacher collins syndrome
Electric
Radiational
Toxic (induced)
Corticosteroids
Miotics
Copper / Iron

Question 3

Metabolic cataract types

Answer 3

Diabetic
Galactosemic
Hypocalcaemic
Error in copper metabolism
Lowe’s syndrome

Question 4

Morphological classification

Answer 4

Capsular (never alone)
Anterior
Posterior
Subcapsular
Anterior
Posterior
Cortical
Nuclear
Polar
Anterior
Posterior

Question 5

Congenital and developmental cataract

Answer 5

Congenital involves embryonic / foetal nucleus.
Developmental involves infantile / adult nucleus , deep part of cortex ) capsule.

Question 6

Clinical types of congenital cataract

Answer 6

Congenital capsular
Anterior
Posterior
Congenital polar
Anterior
Posterior
Congenital nuclear
Involving embryonic nucleus
Cataracta pulverulenta
Involving foetal nucleus
Lamellar
Sutural and axial
Involving whole nucleus
Total congenital cataract
Congenital membranous cataract
Involving adult nucleus + cortex
Coronary cataract
Blue dot cataract

Question 7

Types of sutural and axial cataract

Answer 7

Floriform
Collariform
Spear-shaped
Anterior axial embryonic
Dendritic suture

Question 8

Etiology of congenital cataract

Answer 8

Idiopathic
Hereditary
Without systemic disorders
With systemic disorders
Chromosomal disorders
Skeletal disorders
Central nervous system disorders
Renal system disorders
Maternal factors
Malnutrition
Infections
Drug ingestion
Radiation
Foetal / infantile factors
Deficient oxygenation
Birth trauma
Metabolic disorders
Congenital anomalies
Ocular diseases with developmental
Malnutrition

Question 9

Rubella cataract (Rubella syndrome)

Answer 9

Maternal rubella in 1st trimester.
Child born with pearly white nuclear cataract.
Progressive type
Lens matter (soft + liquify)
Harbour virus (cataractous nucleus)(removal cause severe inflammation -uvietis / endophthalmitis)

Ocular defects (rubella syndrome)
Congenital cataract
Salt-pepper chorioretinopathy
Microphthalmos
Cloudy cornea
Poorly dilated pupil
Ear defect (deafness)
Heart defects
Patent ductus arteriosus
Pulmonary stenosis
Ventricular septal defects

Question 10

Ocular examination of congenital cataract

Answer 10

Ocular examination
Direct ophthalmoscopy (quality of red reflex)
Oblique illumination examination
Fundus examination
Special tests
Fixation reflex
Forced choice preferencial looking test
Visually evoked potential (VEP)
Optic Kinetic Nystagmus (OKN)

Question 11

Lab tests for congenital cataract

Answer 11

Intrauterine injections (TORCH test)
Galactosaemia (urine test)
Lowe’s syndrome (urine chromatography)
Hyperglycaemia (RBS)
Hypocalcaemia (serum calcium+phosphate)(x ray skull)

Question 12

Prognostic factors in congenital cataract

Answer 12

Density of cataract
Unilateral/ bilateral
Time of presentation
Ocular defects associated
Systemic defects associated

Question 13

Indications and timing of paediatric cataract surgery

Answer 13

Partial cataract
Non-surgical (pupillary dilatation)
Bilateral / unilateral dense cataract (early removal)(revent stimulus deprivation amblyopia)

Question 14

Surgical procedure for congenital cataract

Answer 14

Extra capsular cataract extraction technique.
Anterior capsulorrhexis
Lens aspiration / lensectomy

Question 15

Senila cataract

Answer 15

Commonest type of acquired cataract.
Above 50 years
Usually bilateral

Morphological types
Cortical (common)
Nuclear
Posterior subcapsular

Question 16

Risk factors of senile cataract

Answer 16

Age (before 45 yrs- pre senile cataract)
Sex (more in females)
Hereditary (onset + maturation)
UV rays
Dietary factors (deficient in proteins, AA, vit A / C / E / B)
Dehydration crisis (in childhood- diarrhoea, cholera)
Smoking (incresed frequency of nuclear cataract)(causes accumulation of pigmented molecule - yellowing)

Question 17

Causes of pre senile cataract

Answer 17

Hereditary (cataractous changes)
Diabetes Mellitus (nuclear cataract , rapid progress)
Myogonic dystrophy (post. Subcapsular type, christmas tree cataract)
Atopic dermatitis

Question 18

Mechanism of loss of lens transparency

Answer 18

Cortical senile
Denaturation of lens protein (aquaporin mutation, decreased protein synthesis, reversal of Na+ /K+)
Nuclear
Degenerative changes
Nuclear sclerosis
Dehydration+compaction (hard cataract)
Increase in water soluble proteins
Deposition of urochrome + melanin

Question 19

Stages of maturation of cortical type senile cataract

Answer 19

Stage of lamellar separation
Stage of incipient cataract
Immature senile cataract
Mature senile cataract
Hypermature senile cataract (2 forms)
Morgagnian
Sclerotic type

Question 20

Maturation of nuclear senile cataract (events)

Answer 20

Progressive nuclear sclerosis (begins centrally)
Inelastic + hard
Inability to accommodate
Obstruct light rays

Nucleus
Diffusely cloudy (greyish) /tinted (yellow / brown / black / reddish)