Developmental cataract

Definition

Congenital cataract: - Cataract present at birth- Involves embryonic or fetal nucleus Developmental cataract:- Occurs from infancy to adulthood- May involve infantile or adult

nucleus, deeper layers of cortex or the capsule

Etiology Heredity: - Accounts for 1/3rd of congenital

cataracts- Dominant pattern- Common cataracts which are

inherited are: cataracta pulverulenta, zonular cataract, coronary cataract, total cataract

Maternal factors: - Malnutrition- Infections: TORCH- Drugs: thalidomide, corticosteroids- Radiation exposure

Fetal or infantile factors:- Deficient oxygenation due to placental

haemorrhage- Metabolic disorders: hypocalcemia,

storage disorders, galactosemia, neonatal hypoglycemia

- Other congenital syndromes: Lowe’s, myotonica dystrophica, etc

- Birth trauma- Malnutrition Idiopathic

Clinical types Punctate cataract:- Commonest form- Blue dot cataract (cataracta coerulea):

tiny blue dots seen on oblique illumination- Sutural cataract:opacities involving Y

sutures- Cataracta centralis pulverulenta: powdery

fine opacities within embryonic or fetal nucleus

Zonular cataract- Constitutes 50% of all visually significant

cataract- Development is affected at a later stage and a

zone surrounding embryonic nucleus (usually fetal nucleus) becomes opacified, its extent depending on the duration of inhibiting factor

- Sharply demarcated opacity with area within and surrounding the opacity being clear

- Linear spoke like opacities running towards equator: “riders”

- Usually bilateral- Etiology: genetic (dominant inheritance),

environmental (malnutrtion late fetal or early infantile life, vitamin D deficiency)

Fusiform cataract- Also called as spindle shaped

cataract/ axial or coralliform cataract- Anteroposterior spindle shaped

opacity, sometimes with off-shoots giving an appearance resembling a coral

- Etiology: genetic

Nuclear:- Results when development of lens

is inhibited at an early age, so that the central nucleus remains opaque- embryonal nuclear cataract

- Progressive form of nuclear cataract- rubella

Coronary cataract: - Development affected around puberty,

thereby involving deep layers of cortex and most superficial layers of adolescent nucleus

- Club shaped opacities near the periphery of the lens, axial region remaining clear: vision usually not affected

- Non progressive

Anterior polar cataract:- Involves the central part of anterior capsule

and the adjacent cortex- Etiology: delayed formation of anterior

chamber during development (congenital), perforation of corneal ulcer in ophthalmia neonatorum resulting in contact of cornea with anterior lens capsule (acquired)

- May also result in formation of anterior pyramidal cataract (white plaque projecting forwards into the anterior chamber)

Sometimes an anterior cortical cataract may form (due to opacification of underlying cortex)

Reduplicated cataract/ imprint cataract: when subcapsular epithelium grows between the capsular and cortical opacities, clear lens fibres separate the 2 opacities forming an imprint cataract (buried opacity)

Usually non progressive, do not interfere with vision

Posterior polar cataract:- Due to persistence of posterior

part of vascular sheath of the lens (posterior hyaloid artery)

- Usually visually insignificant

Total cataract Congenital membranous cataract :

due to total or partial absorption of a congenital cataract. Very rare