Which statement about the vitreous composition is correct?

Which statement about the vitreous composition is correct?

• A. 99% water; 1% collagen/hyaluronic acid
• B. 80% water; 20% collagen
• C. 60% water; 40% collagen
• D. 50% water; 50% collagen

Answer: (A)

The vitreous is a highly hydrated gel where water is the dominant component. About 99% of its mass is water, while the remaining roughly 1% is organic solids, mainly a collagen–hyaluronan network that gives the gel its structure. Hyaluronic acid binds water and, with a sparse collagen framework, creates a transparent, viscoelastic matrix that supports the retina and allows light to pass with minimal scattering. If the solid content were much higher, as in 20% collagen or 40–50% solids, the substance would be far denser and less transparent, not matching the gel-like, highly hydrated nature of the vitreous.

The vitreous is a highly hydrated gel where water is the dominant component. About 99% of its mass is water, while the remaining roughly 1% is organic solids, mainly a collagen–hyaluronan network that gives the gel its structure. Hyaluronic acid binds water and, with a sparse collagen framework, creates a transparent, viscoelastic matrix that supports the retina and allows light to pass with minimal scattering. If the solid content were much higher, as in 20% collagen or 40–50% solids, the substance would be far denser and less transparent, not matching the gel-like, highly hydrated nature of the vitreous.