What is posterior vitreous detachment?
Posterior vitreous detachment is a common eye condition caused by natural changes to the jelly that fills the eye as we get older. The symptoms tend to be more of an annoyance at first, but after a few weeks or a couple of months, you won’t tend to notice them as much.
It’s usually nothing to worry about – you won’t feel any pain and it won’t damage your eyes or causes vision loss – but in rare cases it can lead to retinal detachment which poses a risk to your sight. That’s why it’s important to get your symptoms checked out as soon as you have them to make sure you get the treatment needed.
Symptoms of posterior vitreous detachment
- Floaters (dark spots or strands that float across your vision)
- Flashes of light at the side of your vision
A tell-tale sign of posterior vitreous detachment is a sudden increase in the number of floaters in your vision, as well as flashes of light. Some people describe the floaters looking like a cobweb across their vision, although you might see them as dots, strands, or squiggles.
These symptoms can last for a few weeks and can feel quite frustrating – but eventually, your brain will learn to ignore them, and they won’t bother you as much.
You should see your optometrist or emergency hospital eye department within 24 hours if you experience any of these symptoms:
- A sudden increase in the number and size of floaters
- An increase in the number of flashing lights you see
- Blurred vision
- The appearance of a dark curtain moving across your vision
Causes of posterior vitreous detachment
Our eyes are filled with a gel-like fluid called the vitreous humour, that maintains the eye’s shape. As we get older, natural changes in the vitreous humour mean that it starts to become more watery and shrinks, pulling away from the light-sensitive layer at the back of your eye, called the retina. This tends to happen after the age of 50, although it is not uncommon for younger people to experience it.
Diagnosing posterior vitreous detachment
Posterior vitreous detachment is usually diagnosed during an eye test, using dilation drops to make your pupils bigger. This allows the optometrist to get a really good look inside your eye to check for signs of posterior vitreous detachment as well as looking at the health of the retina at the back of the eye.
Treatments for posterior vitreous detachment
This condition is a normal part of ageing and there is no specific treatment needed for posterior vitreous detachment – people will find that their symptoms start to get better after a couple of months. In fact, your brain cleverly learns to ignore the floaters in your vision, so you’ll find that they won’t bother you as much.
Treatment is only necessary when there is a risk to the health of your retina, in which case you’ll be referred for urgent treatment to repair a retinal tear, hole, or detachment.
There are several warning signs for retinal detachment, and you should get an urgent re-examination if you experience any of the following:
- A sudden increase in the number of floaters in your vision
- A decrease in visual field
- A veil coming across the vision
Complications and related eye conditions
This is a related eye condition that happens when the light-sensitive layer (the retina) separates from the back of the eye. Posterior vitreous detachment can lead to retinal detachment in some cases, but only a small number of people with PVD will develop this.
Months or years after a posterior vitreous detachment, the inner layer of the retina can begin to thicken into what is known as an epiretinal membrane. While this can cause blurry vision, the vast majority of epiretinal membranes won’t significantly affect your vision, and won’t require any treatment.
During a PVD, as the vitreous comes away from the retina, it can tug on the blood vessels in the retina, causing blood to leak into the jelly of the eye. This is known as a vitreous haemorrhage.