Vitreous Body Anatomy

The vitreous is the mass between the lens and the lining at the back of the retina. It is transparent, colorless, and gelatinous. Vitreous is produced by cells in the cilary body, and is similar to blood plasma or egg whites. The vitreous contains only a few types of cells, including:

- 99% water with sugars, salts, vitrosin, and a network of collagen type II fibers, with the rest mucopolysaccharide hyaluranic acid
- Hyalocytes of Balazs, which reprocess hyaluronic acid
- Phagocytes, which remove unwanted debris from the visual field
- No blood vessels

The water is supported by a negative charge of MPS hyaluronic acid and water. The lens is about 75% water, and the vitreous is about 98% water. Still, the vitreous has a viscosity which is approximately two to four times that of pure water; that is why it has the sort of consistency that it does.

For unknown reasons, the vitreous starts to lose hyaluonic acid when we reach the age of around fifty. As a result, an increasingly watery consistency can occur more quickly.

The vitreous is stationary, as it is pressed against the choroid and is in contact with the retina. It only sticks to the retina in several places. These are the places where posterior vitreal detachment is most likely to occur:

- Macula (the tiny spot in the retina which gives us central vision and detail)
- Anterior retina border
- Optic nerve disc

Unlike the fluid in the aqueous humor, which is constantly replenished, the gel in the vitreous chamber is stagnant. This is why when blood, cells, or other by-products of inflammation make their way into the vitreous, they will stay there until removed surgically. If the vitreous breaks off from the retina, it is vitreous detachment. This phenomenon is far more likely to be found in eyes which are near-sighted, which also experience detachment earlier in life. As we age, the vitreous can become increasingly liquefied and may collapse. Injuries can also cause detachment to occur, as can eye inflammation.

The vitreous is a closed system without blood support. Systemic medications can't help with liquefaction as these medications must be delivered through the blood supply. A treatment for floaters eyes must be directly targeted at the vitreous body.