The eyeball is filled with a clear gel called vitreous, which is made up of mainly water and a protein called collagen. With age the vitreous becomes more watery and less like gel. When the vitreous becomes too soft it loses its shape, comes away from the retina and shrinks in towards the centre of the eye. Once the vitreous detaches from the retina it cannot reattach. This is not a problem as the vitreous does not need to be attached to the retina in order to see well.
The most common cause of Posterior Vitreous Detachment is natural ageing. Most people who have a Posterior Vitreous Detachment are over 50 years, though the condition can occur earlier, especially if short-sighted, if the eye has been injured or if the eye has had previous surgery.
It is normal for both eyes to experience Posterior Vitreous Detachments, usually one at a time, within a year or two of each other.
Posterior vitreous detachment is not painful and it doesn’t cause sight loss, but it can cause symptoms such as floaters (small, dark spots or shapes) and flashing lights. With time the brain learns to ignore these symptoms. Crucially, however, the symptoms of a Posterior Vitreous Detachment are very similar to a different condition called retinal detachment, which is sight threatening. It is important to be examined by an ophthalmologist, or optician, within 24 hours of developing floaters of flashing light symptoms, so that an accurate diagnosis can be made. A retinal detachment requires urgent surgery.
A simple Posterior Vitreous Detachment does not require treatment. 10-15% of people with a Posterior Vitreous Detachment develop a retinal tear which, if not treated, can develop into a retinal detachment. A retinal tear or a retinal detachment can be successfully treated if diagnosed early.
A simple Posterior Vitreous Detachment does not require treatment.
[RNIB/Royal College of Ophthalmologists: Understanding Posterior Vitreous detachment ]
