| What is the vitreous? It is the colorless, | | | | places: |
| transparent, gelatinous mass between the eye's | | | | 1) the optic nerve disc (where the retina sends |
| lens and the lining of the retina. Cells in the cilary | | | | about 1.2 million nerve fibres (axons) to the brain) |
| body produce vitreous, which is similar to egg | | | | 2) the anterior border of the retina |
| white and blood plasma. Vitreous contains only a | | | | 3) the macula, the tiny spot in the retina which |
| few cells: | | | | gives us our "detail" and central vision |
| * Phagocytes: removes unwanted debris from | | | | Posterior vitreal detachment is most likely to |
| the visual field | | | | occur in these three places. |
| * Hyalocytes of Balazs: reprocesses hyaluronic | | | | The gel in the vitreous chamber is stagnant, which |
| acid | | | | is unlike the fluid in the aqueous humor at the |
| * No blood vessels | | | | front of the eye, which is replenished continuously. |
| * 99% Water: with sugars, salts, vitrosin, and a | | | | For this reason when cells, blood, or other |
| network of collagen type II fibers, with the rest | | | | inflammation by-products get in to the vitreous, |
| mucopolysaccharide hyaluranic acid | | | | they stay there until surgically removed. If the |
| A network of collagen and the negative charge of | | | | vitreous separates away from the retina, this is |
| MPS hyaluronic acid supports the water. The | | | | called 'vitreous detachment.' As we get older, the |
| water content of the lens is around 75%, less | | | | vitreous sometimes becomes increasingly liquefied |
| than that of the vitreous, at 98%. Still, the | | | | and can collapse. This is much more likely to occur |
| viscosity of the vitreous is about 2-4 times more | | | | in near-sighted eyes, which experience vitreous |
| than pure water, which is why it has the | | | | detachment earlier and more often. Detachment |
| consistency that it does. For reasons still | | | | can also occur as a result of injuries caused by |
| unknown, around the age of 50 the vitreous | | | | uveitis, or inflammation of the eye. |
| begins to lose hyaluonic acid - this results in | | | | The vitreous is a closed system with no blood |
| quicker changes to an increasingly watery | | | | support; changes such as liquefaction aren't |
| consistency. | | | | affected by systemic medications because these |
| The vitreous is in contact with the retina; this | | | | require delivery to the blood supply. For this |
| helps to keep it stationary as it is pressed against | | | | reason, a treatment for eye floaters must be |
| the choroid. It doesn't stick to the retina but in 3 | | | | directly targeted at the vitreous body. |