The vitreous humor occupies 4/5 of the eye and is a clear jelly-like substance that is 99% water and the rest is a collagen fiber scaffold. A healthy and intact vitreous body forms a good support for the retina and is able to maintain the morphology of the eye.
The vitreous is tightly attached to the first 1/3 of the eye wall and does not detach even when torn. There are many collagen fibers that emanate from the eye wall and extend toward the vitreous, eventually reaching the optic papilla, and are thus considered the beginning of the vitreous or the base of the vitreous. There is a clear, tube-like structure in the center of the vitreous called the Cloquet’s canal, which is essentially a concentrated vitreous and is more tightly connected to the optic papilla. As the vitreous becomes liquefied and atrophied, this area is stretched and detached and can appear as an impression, called the Weiss ring, which is also a common factor in vitreous clouding.
The vitreous is loosely attached to the rest of the eye wall and tends to detach as the vitreous liquefies and atrophies. When the detached vitreous appears to oscillate and strike the retina, there is a sensation of seeing lightning, called flash sensation.
The vitreous body has no blood vessels and cannot recover once liquefaction and atrophy occur due to malnutrition. Once the retina is torn, the vitreous fluid enters the subretina and causes retinal detachment. When blood enters the vitreous body it is also not easily absorbed and some of it will remain in the vitreous body, gradually degenerating and causing vitreous clouding. The vitreous body has a certain support role for the eye. When the vitreous body liquefies and atrophies, the intraocular pressure will decrease accordingly than before.
Posterior vitreous detachment is bound to occur with age, and the higher the myopia, the earlier it occurs; the worse the nutrition, the earlier it occurs. There is no way to prevent posterior vitreous detachment from occurring, and it does not directly cause eye disease or require treatment.