A posterior vitreous detachment (PVD) occurs when the vitreous pulls away from the retina. Vitreous is a jelly-like substance occupying the middle part of the eye. The retina is a layer of cells that line the back wall of the eye and is sensitive to light. Vitreous is usually attached to the retina. It is connected to the retina by millions of microscopic fibers. When these fibers break, the vitreous completely separates from the retina.
A PVD does not cause pain or harm to the eye. It also does not lead to permanent loss of vision. An individual will experience decreased vision and see lots of floaters and flashes of light in his/her field of vision. Because it is a natural occurrence, 75% of people aged 65 and above may develop a PVD. A PVD will often occur in the other eye as well over time.
Also Known As
Causes and Risk Factors
Natural changes to the vitreous gel cause a PVD. Due to age and the natural wear and tear, the vitreous becomes more watery and is unable to keep its shape. It thus shrinks and moves away from the retina to the center of the eye. The following risks are associated with PVD:
- Myopia (nearsightedness)
- Cataract or other eye surgeries
- Trauma or injury to the eye
Signs & Symptoms
The symptoms related with PVD include:
- Floaters – Tiny spots moving in the field of vision. A sudden emergence or increase in their numbers should be a matter of concern
- Decreased or blurred vision
- Flashes of light in an individual’s side vision – They are more noticeable in dark surroundings
- Movement of a dark curtain up, down and across the vision
he eye care professional will do the following to diagnose a PVD:
- A comprehensive dilated eye examination
- An optical coherence tomography (OCT) test – An OCT will be used if the vitreous gel is so clear that it hinders the eye doctor from detecting the PVD. The OCT will use light to create a 3-dimensional image of the eye to enable a physical evaluation
- An ocular ultrasound – Imaging technology that uses high-frequency sound waves to generate pictures of the eye’s structure
Treatment of PVD aims to restore the function of the vitreous to improve vision.
A PVD that usually occurs without damaging the retina requires no medical treatment. Professionals are yet to agree on whether eye exercises, diet changes or vitamins can assist patients with a PVD.
Surgical treatment will be administered if a retinal tear happens during a PVD. The surgeon uses a laser or cryopexy (freezing treatment) to seal the retina to the wall of the eye. In case of a retinal detachment occasioned by a PVD, surgery is recommended. If the floaters persist, the surgeon may perform a vitrectomy or scleral buckle to remove them.
About 85% of patients who experience PVD never develop complications. Usually, the floaters and flashes will subside within three months.
In most cases, a PVD is harmless since it does not threaten vision. However, some people may have to deal with bothersome floaters. The floaters appear as circles, cobwebs, dots, lines and clouds. They may move a lot or not move at all. They are very irritating when they move to the center of vision but less troublesome if they move to the peripheral vision. However, the floaters become less noticeable over time.
An individual with a PVD may also have to deal with the long-term effects of small flashes of light. For most people, the flashes disappear when the vitreous gel gets fully detached from the retina.
Also, people with PVD might feel that they are looking through a cobweb. This feeling also disappears when the vitreous detaches fully from the retina.
If a retinal tear happens, it can lead to the more serious macular hole or retinal detachment. A retinal tear results from the vitreous pulling too hard from the back of the eye. The vitreous then takes a piece of the retina with it leading to a retinal detachment. A retinal detachment and macular hole both cause permanent loss of vision.
People who notice floaters for the first time should consult an eye doctor regularly to prevent a retinal detachment.