• 1 AbnormalitiesSECTION Congenital

Lenticonus and Lentiglobus

Key Facts

•Localized bulge (lenticonus) or generalized protrusion (lentiglobus) of anterior or posterior lens capsule

•Presumably due to lens capsular thinning

•Rare (1–4/100 000)

•Congenital or acquired

•Unilateral or bilateral

•Anterior rarer than posterior types

•Anterior lenticonus associated with Alport syndrome (90%)

•Posterior lenticonus usually idiopathic

Clinical Findings

•May present as progressive myopia, high astigmatism (irregular)

•Oil droplet reflex on retinoscopy

•Adjacent cortical opacification

•Uncommonly, spontaneous capsular rupture

Ancillary Testing

• None

Differential Diagnosis

•Galactosemia and galactokinase deficiency (oil droplet cataracts)

•Posterior polar cataract

•Persistent hyaloid remnants

Treatment

•Cataract surgery if:

• associated lens opacity • high astigmatism • anisometropia

Prognosis

•Favorable on removal of associated cataract

•Vigilant postoperative occlusion to avoid amblyopia in children

Fig. 1.1 A dramatic view of anterior lenticonus in a patient with idiopathic lenticonus.

Fig. 1.2 The same patient also has posterior lenticonus. Although not as dramatic as his anterior lenticonus, the out-pouching of the posterior lens is still obvious.

Fig. 1.3 The classic oil droplet reflex of lenticonus is best seen on retroillumination.

Lentiglobus and Lenticonus

• 1 AbnormalitiesSECTION Congenital

Lens Coloboma

Key Facts

•Equatorial lens flattening or notch due to a focal absence of lens zonules

•Underlying colobomatous ciliary body

•Usually sporadic (occasionally dominant)

•Unilateral or bilateral

•Isolated finding or associated with other ocular colobomas

•Systemic associations:

•Patau syndrome (trisomy 13) • cat eye syndrome (trisomy 22) • coloboma, heart defects, choanal atresia, retarded development, genital and ear anomalies (CHARGE) • basal encephaloceles or cysts • Goldenhar syndrome • other syndromes

Clinical Findings

•Usually inferonasal quadrant

•Associated sectoral cataract

•Phacodonesis

•Often associated with colobomas of iris, ciliary body, retina, and choroid

Ancillary Testing

• None

Differential Diagnosis

•Lens-dislocating diseases (e.g. Marfan syndrome and homocystinuria)

•Adjacent pars plicata or ciliary body tumor (e.g. melanocytoma)

•Contusion or intraoperative trauma (acquired zonular defects)

•Normal variant (minor indentations between inserting zonules in young lenses)

Treatment

•Intervention usually not necessary

•When cataract surgery is indicated, a capsular tension ring should be considered

Prognosis

• Excellent when isolated

Fig. 1.4 A myopic patient with primary lens coloboma.

Fig. 1.5 Note the scalloped nasal edge of this 12-year old’s lens coincident with absent lens zonules.

Fig. 1.6 Left eye of the same 12-year- old boy, taken at a different angle, showing a ciliary body cyst (seen inferonasally) as the cause of this secondary lens coloboma.

Fig. 1.7 Another case of secondary lens coloboma due to a ciliary body tumor.

Coloboma Lens