Retinal Detachment
A retinal detachment is, in many cases, a medical emergency and needs to be assessed as soon as possible so that your ophthalmologist is able to make decisions about any treatment you may need.
About Retinal Detachment
Retinal detachment occurs when the retina separates from the back of the inside of the eye, rather like wallpaper peeling off a damp wall. The retina needs to be attached to the back of the eye to survive and work properly, so if a retinal detachment is not detected and treated quickly it may result in the loss of some or all the vision in your eye.
How your eye works
When you look at something, light passes through the front of your eye, and is focused by the lens onto your retina. The retina is a delicate tissue that coats the inside of your eye. The retina converts the light into electrical signals that travel along the optic nerve to your brain. The brain interprets these signals to “see” the world around you. The retina is also supplied with blood by a delicate network of blood vessels on its surface.
Light is focused onto a tiny area of the retina called the macula, which is about the size of a pinhead. This highly specialised part of the retina is vital, because it enables you to see fine detail when you are looking directly at something such as words, photos or the television. Your macula also gives you much of your ability to see colours. The rest of the retina gives you side vision (peripheral vision).
The eye is filled with a clear substance called the vitreous gel. Light passes through the gel to focus on the macula.
Causes
Most retinal detachments happen because a tear or hole in the retina allows fluid to leak between the retinal layers and this then causes the retina to detach. Holes in the retina can occur because of changes that happen as you age, whereas tears happen because the retina has been pulled and torn. Tears mostly occur when the vitreous gel suddenly becomes detached from the retina (known as acute posterior vitreous detachment or PVD). Most gradual PVD does not result in retinal detachment. A blow to the head cannot cause retinal detachment, though a direct blow to the eye may do so.
Other eye conditions such as diabetic retinopathy can result in fibrous scar tissue forming inside the vitreous and on the surface of the retina. This scar tissue can then pull on the retina (traction) causing a detachment. This type of traction on the retina can also pull the retina away from the back of the eye.
A rare type of retinal detachment can occur when fluid from the vessels behind the retina leaks between the retinal layers without there being a hole or tear present. This type of detachment happens because of another condition such as an inflammation or tumour.
Who is at risk?
Retinal detachment is rare. It only occurs in about 1 in 10,000 people each year. Retinal detachment can happen to someone of any age but is very rare under the age of 16 and most commonly happens to people aged between 60 and 70 years. This is because changes to the vitreous gel are very common in older people, occurring in 60 per cent of people over 70 years of age. For the vast majority of people these changes do not result in any serious complications.
You have an increased risk of retinal detachment if you:
- Are very short sighted (more than minus 6.00 D)
- Have had trauma (injury or blow) directly to the eye
- Have already had a detachment in one eye, then there is an increased likelihood of a detachment in the other eye. Between 2 and 10 per cent of detachments occur in both eyes
- Have a family history of retinal detachment.
Symptoms that warn of a retinal detachment
