The vitreous (Latin for "glassy") humor is a gel which fills the eye behind the lens. Between it and the retina is the vitreous membrane. With age the vitreous humor changes, shrinking and developing pockets of liquefaction, similar to the way a gelatin dessert shrinks and detaches from the edge of a pan. At some stage the vitreous membrane may peel away from the retina. This is usually a sudden event, but it may also occur slowly over months. Age and refractive error play a role in determining the onset of<unk>  in a healthy person.<unk>  is rare in emmetropic people under the age of 40 years, and increases with age to 86% in the 90s. Several studies have found a broad range of incidence of<unk> , from 20% of autopsy cases to 57% in a more elderly population of patients (average age was 83.4 years). People with myopia (nearsightedness) greater than 6 diopters are at higher risk of<unk>  at all ages.<unk>  does not directly threaten vision. Even so, it is of increasing interest because the interaction between the vitreous body and the retina might play a decisive role in the development of major pathologic vitreoretinal conditions, such as epiretinal membrane.<unk>  may also occur in cases of cataract surgery, within weeks or months of the surgery. The vitreous membrane is more firmly attached to the retina anteriorly, at a structure called the vitreous base. The membrane does not normally detach from the vitreous base, although it can be detached with extreme trauma. However, the vitreous base may have an irregular posterior edge. When the edge is irregular, the forces of the vitreous membrane peeling off the retina can become concentrated at small posterior extensions of the vitreous base. Similarly, in some people with retinal lesions such as lattice retinal degeneration or chorio-retinal scars, the vitreous membrane may be abnormally adherent to the retina. If enough traction occurs the retina may tear at these points. If there are only small point tears, these can allow glial cells to enter the vitreous humor and proliferate to create a thin epiretinal membrane that distorts vision. In more severe cases, vitreous fluid may seep under the tear, separating the retina from the back of the eye, creating a retinal<unk> . Trauma can be any form from a blunt force trauma to the face such as a boxer's punch or even in some cases has been known to be from extremely vigorous coughing or blowing of the nose.
Posterior vitreous detachment
Ischemic optic neuropathy
Vitreous hemorrhage
Posterior ischemic optic neuropathy
Anterior ischemic optic neuropathy
Arteritic anterior ischemic optic neuropathy
Acute retinal necrosis
Optic neuritis