What structure (arrows) is shown in the eye of this 18-week fetus?
(Images courtesy of Mayank Chowdhury, MD)
1. Hyaloid artery
The vascular structure seen is the hyaloid artery, which is considered a normal finding until 32 weeks' gestation. Presence of this vessel beyond 32 weeks' gestation is associated with visual impairment during neonatal life, with possible development of cataract.