1. Glassy; resembling glass. 2. vitreous body [L. vitreus, glassy, fr. vitrum, glass]
persistent anterior hyperplastic primary v. a unilateral congenital abnormality occurring in full-term infants; characterized by a retrolental fibrovascular membrane formed by persistent primary v. with remnants of the hyaloid artery and tunica vasculosa lentis; associated with leukokoria, microphthalmos, shallow anterior chamber, and elongated ciliary processes.
persistent posterior hyperplastic primary v. a unilateral congenital anomaly in full-term infants; associated with a congenital retinal fold and a v. membranous stalk containing remnants of the hyaloid artery.
primary v. the v. first formed in the embryo between the optic cup and the lens vesicle, and later vascularized by the hyaloid artery and its branches.
secondary v. avascular v. formed around the primary v.
tertiary v. v. fibrils derived from the neuroepithelium of the ciliary body and forming the ciliary zonule.
Browse Medical References: