Posterior Vitreous detachment
Flashes and floaters/ Posterior Vitreous detachment (PVD)
The inside of the eye is filled with a jelly-like substance. This is called vitreous humour (or just “vitreous” for short) and it is transparent. The retina lines the back of the eye like wallpaper.
A natural ageing process causes this vitreous jelly to become more watery and sloppy. As the eyeball moves around, the sloppy vitreous jelly moves around inside the vitreous cavity. This causes the vitreous to pull away from the retina, and in time, the vitreous can pull free and separate from the retina. This is called a posterior vitreous detachment or PVD for short.
What will I notice?
In itself posterior vitreous detachment is not harmful, but when the vitreous pulls away from the retina in this way some people notice flashing lights and floaters (cobwebs) in their vision. This can be quite sudden.
Will it affect my vision?
The floaters are harmless but can be annoying. However with time they become less noticeable. The flashing lights will often subside within 4 to 12 weeks, although sometimes this can take a lot longer.
What do I need to do?
You have been diagnosed with a PVD and so far there are no serious complications. If you experience a sudden onset of more floaters or a marked increase in flashes in the vision you need to be examined again by an optician or an ophthalmologist. (See also the section below about retinal detachment.)
What complications could occur?
Occasionally as the vitreous separates from the retina, it can cause a retinal tear. A tear like this can sometimes cause a bleed into the vitreous cavity and therefore obstruct the vision. Usually this will clear on its own over time. A tear can also lead to retinal detachment, where the retina peels away from the wall of the eye like wallpaper coming off the wall of a room. A retinal detachment can cause permanent loss of vision if left untreated, but fortunately timely treatment and surgery is effective at preventing the eye losing all its sight in 95% of the cases.
These complications are more common in short sighted people (myopes), and commoner with age, but can occur in anyone.
What are the symptoms of retinal detachment?
1. A growing dark curtain appearing to blank out part of the vision, possibly preceded by a further shower of floaters (with or without flashes in the vision)
2. loss of clarity of central vision (if the detachment spreads to involve the centre of the retina)
If you experience any of these symptoms please attend the nearest Eye Casualty as soon as possible, this should be the next day if it is already evening.