Posterior vitreous detachment

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Posterior vitreous detachment
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A posterior vitreous detachment (PVD) is a condition of the eye in which the vitreous membrane separates from the retina.[1] 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).

The condition is common for older adults; over 75% of those over the age of 65 develop it. Although less common among people in their 40s or 50s, the condition is not rare for those individuals. Some research has found that the condition is more common among women.[2][3]

Symptoms

Weiss ring: a large, ring shaped floater that is sometimes seen if the vitreous body releases from the back of the eye

When this occurs there is a characteristic pattern of symptoms:

  • Flashes of light (photopsia)
  • A sudden dramatic increase in the number of
    floaters
  • A ring of floaters or hairs just to the temporal side of the central vision

As a posterior vitreous detachment proceeds, adherent vitreous membrane may pull on the retina. 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.[citation needed]

If a retinal vessel is torn, the leakage of blood into the vitreous cavity is often perceived as a "shower" of floaters. Retinal vessels may tear in association with a retinal tear, or occasionally without the retina being torn.[citation needed]

A Weiss ring can sometimes be seen with ophthalmoscopy as very strong indicator that vitreous detachment has occurred. This ring can remain free-floating for years after detachment. [citation needed]

Complications

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.

The risk of retinal tears and detachment associated with vitreous detachment is higher in patients with myopic retinal degeneration,

retinal tears
/detachment.

Causes

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 PVD in a healthy person. PVD 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 PVD, from 20% of autopsy cases to 57% in a more elderly population of patients (average age was 83.4 years).[4]

People with

diopters
are at higher risk of PVD at all ages. Posterior vitreous detachment 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.[citation needed]

PVD may also occur in cases of cataract surgery, within weeks or months of the surgery.[5]

The vitreous membrane is more firmly attached to the retina

punch
or even in some cases has been known to be from extremely vigorous coughing or blowing of the nose.

Diagnosis

Posterior Vitreous Detachment is diagnosed via dilated eye examination. For some patients the vitreous gel is extremely clear and so it can be hard to see the PVD. In these cases, additional imaging such as Optical Coherence Tomography (OCT) or ocular ultrasound are used.[6]

Treatment

Therapy is not required or indicated in posterior vitreous detachment, unless there are associated

retinal tears, which need to be repaired.[7] In absence of retinal tears, the usual progress is that the vitreous humor will continue to age and liquefy and floaters will usually become less and less noticeable, and eventually most symptoms will completely disappear.[7] Prompt examination of patients experiencing vitreous humor floaters combined with expeditious treatment of any retinal tears has been suggested as the most effective means of preventing certain types of retinal detachments.[8]

See also

References

  1. ^ Gauger E; Chin EK; Sohn EH (17 November 2014). "Vitreous Syneresis: An Impending Posterior Vitreous Detachment (PVD)". University of Iowa Health Care: Ophthalmology and Visual Sciences; See "Discussion" following "Clinical Course".{{cite web}}: CS1 maint: postscript (link)
  2. PMID 10163464
    .
  3. ^ "Posterior vitreous detachment". rnib.org.uk. 2023-02-28. Retrieved 3 November 2015.
  4. ^ Acta Ophthalmol. 2012 May;90(3):e179-84. doi: 10.1111/j.1755-3768.2011.02310.x. Epub 2011 Nov 22.Prevalence of early and late stages of physiologic PVD in emmetropic elderly population. Schwab C, Ivastinovic D, Borkenstein A, Lackner EM, Wedrich A, Velikay-Parel M.
  5. PMID 18776863
    .
  6. ^ Thompson, John. "Posterior Vitreous Detachment". American Society of Retinal Specialists. ASRS. Retrieved July 11, 2017.
  7. ^ a b "Posterior Vitreous Detachment". Cleveland Clinic. Retrieved 2008-12-24.
  8. PMID 8090453
    .

External links

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