B-scan ocular ultrasonography in preterm and term infants.
PURPOSE: To evaluate the normal B-scan ocular ultrasonographic findings in preterm and term newborns. This information would be useful in making perinatal ocular diagnoses, especially in consideration of the rapidly changing eyes of normal infants shortly after birth. METHODS: One hundred two healthy infants aged 28 to 48 weeks postconception were prospectively studied. Eighty-six had complete sonograms, while others had incomplete examinations due to systemic instability. B-scan ultrasonography was conducted through acoustic coupling medium and a closed eyelid using the Coopervision Ultrascan 404 unit. The ultrasound findings were evaluated relative to the infant's postconceptional age and weight at examination and the axial lengths of each eye. The ultrasonographer, who determined the presence of abnormal findings, was masked to the parameters mentioned above. RESULTS: Four specific findings frequently were noted in newborns that would be considered abnormal in adult eyes. These were: 1) a visible Tenon's capsule; 2) prominent superior ophthalmic vein; 3) sonolucent extraocular muscles; and 4) vitreous opacities. These findings were more common in the more premature infants (P < 0.01 by t test). CONCLUSIONS: The presence of these four ultrasonographic findings in the eyes of infants should be considered normal, and should not necessarily prompt further work up until after the perinatal period.