ULTRASOUND OF CONGENITAL CATARACTS

By the 12th week of gestation the fetal eyes and lenses have developed sufficiently so that they can be seen in both the coronal and transverse planes of the orbits (1).

• Unilateral or bilateral.
• Boundary echoes are more prominent, thickened and irregular. The borders become crenated and hyperechogenic.
• ± cluster or hypoechogenic material.
• Substance of the lens becomes more echogenic (2). This is due to denaturation of lens protein resulting in the formation of an opaque insoluble precipitate (3).
• Highly echogenic area within the fetal eye (4).

• Failure to visualize the hyaloid artery has been reported. It is not known whether this is due to the opacity of the lens or whether there is an association between cataracts and pathology of the hyaloid artery.
• Mild to moderate cases may not be detected antenatally (5,6)

	Early unilateral cataract

REFERENCES

1. Bronshtein M, Zimmer E, Gershoni-Baruch R et.al. First and second trimester diagnosis of fetal defects and associated anomalies: Report of eight cases. Obstet Gynecol 1991;7:443.
2. Munk P, Vellet A, Levin M et.al. Sonography of the eye. AJR 1991;157:1079.
3. Kohn BA. The differential diagnosis of cataracts in infancy and childhood. Am J Dis CHILD 1976;130:184-192.
4. Drysdale K, Kyle PM, Sepulveda W. Prenatal detection of congenital cataracts. Ultrasound Obstet Gynecol 1997;9:62-63.
5. Zimmer EZ, Bronshtein M, Ophir E et.al. Sonographic diagnosis of fetal congenital cataracts. Prenat Diagn 1993;13:503-511.
6. Gaary EA, Rawnsley E, Marin-Padilla JM et.al. In utero detection of fetal cataracts. J Ultrasound Med 1993;12:234-236,