Proliferative Vitreoretinopathy

Proliferative vitreoretinopathy (PVR) occurs when scar tissue forms on top of or under the retina after retinal detachment, which prevents the retina from falling back into place, and reattaching.  PVR can happen in retinal detachment cases either before or after surgery. PVR is uncommon, occurring in about 5-10% of retinal detachments. However, when PVR does occur after surgery, it is the most common reason for a retinal detachment surgery to fail.

There are no proven measures to prevent PVR.

What causes PVR?

When there is a tear or hole in the retina, cells that normally reside under the retina can go through the hole and settle on top of the retina. These cells tend to form sheets of a scar tissue on the surface of (and sometimes underneath) the retina. The scar tissue then contracts, which folds and pulls on the retina. In cases after retinal detachment surgery, this causes a second or repeat retinal detachment. In cases before retinal detachment surgery, this contraction of the scar tissue makes it more difficult to reattach the retina during surgery, and reduces the success rate of surgery. 

Retinal detachment with proliferative vitreoretinopathy (PVR)

What are the risk factors of PVR?

Risk factors include large, multiple or giant retinal tears, or retinal detachments that are not treated early. Bleeding within the eye, increased inflammation in the eye, trauma, and having had multiple previous retinal detachment operations also increase the risk. Cigarette smoking is also a risk factor for PVR.

Early detection and treatment of retinal detachment can reduce the risk of PVR, and so regular eye examinations may be important. 

Diagnosis of PVR is made through clinical examination. Your ophthalmologist will administer eye drops to enlarge (dilate) the pupils temporarily so that they can examine the retina.

Treatment of PVR usually requires surgery. There are different surgical treatment options, and your ophthalmologist will discuss the pros and cons of these options with you, and recommend a suitable treatment plan.

The main surgical treatment options are:

• Scleral buckling. Your ophthalmologist may choose to place a scleral buckle which is a silicone band that encircles the eye like a belt. The scleral buckle acts externally to reattach the retina.
  
  
• Vitrectomy. A vitrectomy is a form of "keyhole" surgery that uses small instruments to enter the eye to remove the vitreous gel in the eye. This allows the surgeon to peel off the PVR scar tissue, and reattach the retina internally. The eye will usually be filled with a gas bubble or silicone oil at the end of surgery, to help with holding the retina in place, and keeping it attached. Following surgery, your doctor may instruct you to maintain a specific head position (usually face-down) for up to two weeks after surgery, and if a gas bubble was injected, you would also need to avoid air travel until the gas bubble dissolves.
  

The success of improving vision after surgery for PVR varies from person to person and ranges from 60% to 80%. Some eyes with severe PVR may have very little chance of improving vision. In such cases, surgery may not be recommended.