![]() In more severe cases, vitreous fluid may seep under the tear, separating the retina from the back of the eye, creating a retinal detachment. 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. If enough traction occurs the retina may tear at these points. 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. 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. However, the vitreous base may have an irregular posterior edge. The membrane does not normally detach from the vitreous base, although it can be detached with extreme trauma. The vitreous membrane is more firmly attached to the retina anteriorly, at a structure called the vitreous base. PVD may also occur in cases of cataract surgery, within weeks or months of the surgery. 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. Posterior vitreous detachment does not directly threaten vision. People with myopia (nearsightedness) greater than 6 diopters are at higher risk of PVD at all ages. Several studies have found a broad range of incidence of PVD, from 20% of autopsy cases to 57% in a more elderly population of patients (average age was 83.4 years). PVD is rare in emmetropic people under the age of 40 years, and increases with age to 86% in the 90s. This is usually a sudden event, but it may also occur slowly over months.Īge and refractive error play a role in determining the onset of PVD in a healthy person. At some stage the vitreous membrane may peel away from the retina. 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. Between it and the retina is the vitreous membrane. The vitreous (Latin for "glassy") humor is a gel which fills the eye behind the lens. The risk of retinal tears and detachment associated with vitreous detachment is higher in patients with myopic retinal degeneration, lattice degeneration, and a familial or personal history of previous retinal tears/detachment. The risk of retinal detachment is the greatest in the first 6 weeks following a vitreous detachment, but can occur over 3 months after the event. This ring can remain free-floating for years after detachment. Ī Weiss ring can sometimes be seen with ophthalmoscopy as very strong indicator that vitreous detachment has occurred. ![]() Retinal vessels may tear in association with a retinal tear, or occasionally without the retina being torn. If a retinal vessel is torn, the leakage of blood into the vitreous cavity is often perceived as a "shower" of floaters. While there are no pain fibers in the retina, vitreous traction may stimulate the retina, with resultant flashes that can look like a perfect circle. A ring of floaters or hairs just to the temporal side of the central visionĪs a posterior vitreous detachment proceeds, adherent vitreous membrane may pull on the retina.A sudden dramatic increase in the number of floaters.When this occurs there is a characteristic pattern of symptoms: Symptoms Weiss ring: a large, ring shaped floater that is sometimes seen if the vitreous body releases from the back of the eye Some research has found that the condition is more common among women. Although less common among people in their 40s or 50s, the condition is not rare for those individuals. The condition is common for older adults over 75% of those over the age of 65 develop it. It refers to the separation of the posterior hyaloid membrane from the retina anywhere posterior to the vitreous base (a 3–4 mm wide attachment to the ora serrata). Medical condition Posterior vitreous detachmentĪ posterior vitreous detachment ( PVD) is a condition of the eye in which the vitreous membrane separates from the retina.
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