Lens & Cataract

Congenital Defects of Lens

Congenital Aphakia Lenticonus and Lentiglobus Lens Coloboma Mittendorf’s Dot (Hyaloid Corpuscle) Epicapsular Star Micro-sphero Phakia Ectopia Lentis

Components of tunica vasculosa lentis

Congenital Defects of Lens

Congenital Aphakia Very rare Associated other eye malformations ± Primary: Lens plate fails to form Secondary:

More common than primary aphakia

It occurs when developing lens is

spontaneously absorbed

Congenital Defects of Lens

Lenticonus and Lentiglobus Lenticonus

UL

Axial in location

Localized cone-shaped deformation of

anterior / posterior lens surface

Posterior more common

Anterior (Alport syndrome) and often BL.

Posterior lenticonus viewed by retroillumination

Congenital Defects of Lens

Lenticonus and Lentiglobus Lentiglobus

Shperical localized lens surface deformation

Posterior> anterior May be associated with lens opacities Retinoscopy – distorted/Myopic reflex

(center) Retroillumination – Deformation visible

in red reflex as “Oil droplet” (cf. “Oil droplet” of galactosemia)

Congenital Defects of Lens

Lens Coloboma An anomaly of lens shape

Primary: wedge shaped defect in lens

periphery (isolated anomaly)

Secondary: flattening/indentation of

lens periphery due to lack of ciliary body

or zonular development

Coloboma of the lens (arrow) viewed by retroillumination

Congenital Defects of Lens

Lens Coloboma Location:

Inferiorly May be associated with uveal

colobomas

Adjascent lens opacities ±

Cortical/capsular thickening

Zonular attachments in the region of

coloboma usually show some defects

Congenital Defects of Lens

Mittendorf’s Dot (Hyaloid corpuscle)

Common anomaly observed in many

healthy eyes Remnant of posterior vascular capsule of

tunica vaculosa lentis Small, dense white spot inferior nasal to

posterior pole of lens Sometimes associated with a fibrous tail

projecting into the vitreous body

Components of tunica vasculosa lentis

Congenital Defects of Lens

Epicapsular Star

Remnant of tunica vasculosa lentis

(common)

Star shaped brown/golden flecks on

the central anterior capsule

Often called chicken tracks

Congenital Defects of Lens Micro-sphero-phakia

Lens spherical and small in diameter (Eye highly myopic)

Entire lens visible through dilated pupil Isolated anomaly/associated with other

anomalies like: Marfan syndrome Peter’s anomaly Alport syndrome Weill-Marchesani syndrome Congenital rubella Lowe syndrome

Congenital Defects of Lens Micro-sphero-phakia

Lens may block pupil (ACG):

Miotics aggrevate

Cycloplegics relieve an attack of ACG

Treatment: Laser iridotomy

Developmental defects

Ectopia lentis Ectopia lentis: Displacement of the lens

Congenital Developmental Acquired

Subluxation: Partial displacement from its normal position but remains in the pupillary area

Upward lens subluxation in Marfan syndrome