Floaters & Flashing Lights
Posterior vitreous detachment (PVD)
Posterior vitreous detachment (PVD) is a natural change in the eye which does not normally cause sight loss. It is very common and most people will develop it at some stage in their lives. Although it can cause some annoying symptoms, it does not cause pain or harm the eye. In the vast majority of cases, PVD will not lead to long term changes in the eye.
The vitreous is a jelly like substance that fills the inside of the eye, behind the lens and in front of the retina. The vitreous is pressed up against the retina, but can pull away from the retina, a process called a posterior vitreous detachment. As this happens, the outer coating of the vitreous jelly can fragment producing floaters. Floaters vary greatly in shape and size from tiny grey dots, to dark rings, lines, insect like shapes and less distinct veil or curtain like shapes. Floaters will often break up and become less noticeable over a period of three to four months but do not usually disappear completely.
When a posterior vitreous detachment occurs, there may also be flashing lights associated with this. These do not indicate that something more serious has occurred but are a more dramatic type of PVD as it is hard to ignore the flashing lights that occur at irregular intervals. The flashing lights usually settle spontaneously after a few weeks.
Over 75 per cent of the population over the age of 65 develop a PVD, and it is not uncommon for it to develop in someone’s 40s or 50s. PVD is not a sign of a disease or eye health problem. For most of us a PVD happens naturally as we get older.
If I have had a PVD do I need to have my eyes checked?
When a PVD occurs, the vitreous jelly pulls away from the retina. Usually the retina is completely unaffected by this process. However, the vitreous can occasionally have some unusually firm connections to the retina, and as the vitreous pulls away it creates a tear or a hole in the retina. If left untreated, the vitreous can seep under the retinal tear and strip off the retina, leading to a retinal detachment. For this reason, it is always sensible to have a prompt eye examination with an optometrist or ophthalmologist at the onset of new flashing lights or floaters to rule out the possibility of a retinal problem.
Is there any treatment to get rid of floaters?
At the moment there are no drops or tablets that will get rid of floaters. There is no evidence to show that eye exercises, diet changes or vitamins can help a PVD. Because PVD floaters, in most cases, clear up on their own, the possible benefits of surgery do not outweigh the risks involved.
A minority of ophthalmologists offer laser treatment for floaters. However, this is not recognised as a standard treatment for floaters in the UK and it is not widely practised. Some studies have reported that this treatment only helps to partially reduce floaters in a third of cases. It may make the large floaters smaller but it does not seem to improve vision in the long run. There is concern that the possible risks of laser surgery outweigh the benefits that may be gained.
There is a surgical procedure called a “vitrectomy” which removes the vitreous jelly from the middle of the eye and in doing so can reduce the number of floaters. It is a major operation and it is not usually offered to patients with PVD due to the risks involved.