Electron microscopic study of the developing human vitreous collagen fibrils.

Vitreous fibrils, and collagen fibrils in other ocular tissues, were observed in 5-, 6- and 7-weeks human embryos. The vitreous fibrils in 7-weeks embryos were distinctly different from the fibrils of other ocular tissues. The vitreous fibrils near the rim of the optic cup were similar to the fibrils in the anterior cavity of the lens vesicle in the 6-week embryo. Broad fibrils were demonstrated with a diameter of 30-40 nm and a striated banding pattern of about 60 nm periodicity.