Retinal detachment is a rare but serious and sight-threatening condition that occurs when the retina – the light-sensitive inner lining of the back of the eye – becomes separated from the underlying tissue. This may be caused by a hole or tear in the retina which allows fluid to get underneath. This weakens the attachment of the retina which then becomes detached – rather like wallpaper peeling off a damp wall. A detached retina can also be caused by an injury or may be a consequence of other eye conditions or surgery.
The most common symptom of a detached retina is a shadow or curtain spreading across the vision of one eye. You may also experience bright flashes of light and/or showers of dark spots called floaters, which may blur or distort your vision. These symptoms are never painful.
Many people experience flashes or floaters and these are not necessarily a cause for alarm. However, if they are severe and seem to be getting worse, and/or vision is being lost, a doctor should be seen urgently. Prompt treatment can often minimise the damage to the eye.
The most common cause of retinal detachment is tiny breaks developing inside the retina. The breaks allow the fluid found between the retina and the lens of the eye to leak underneath the retina. A build-up of fluid can cause the retina to pull away from the blood vessels that supply it with blood. Without a constant blood supply, the nerve cells inside the retina will die.
These breaks are thought to develop due to:
Very short-sighted people have the greatest risk of developing age-related retinal detachment (though the risk is still very small) because they are often born with a thinner than normal retina in the first place. Previous eye surgery, such as cataract removal, may also make the retina more vulnerable to damage. In some cases, a tear can develop if the eye is suddenly injured, such as by a punch to the face.
Although detached retina affects only about 1 person per 10,000, it is more common in middle-aged people and those who are very shortsighted. If you have a detached retina in one eye, the risk of developing one in the other eye is increased. Very rarely, younger people can have a weakness of the retina, or it can be detached as a result of a blow to the eye or head. Retinal detachment can also occur as a result of laser refractive surgery (LASIK) but this is a rare complication. Cataract surgery, ocular tumours and diabetic eye disease are other possible causes.
A detached retina needs urgent medical attention. The sooner the retina is reattached, the better the chances of regaining vision. With early help, it may only be necessary to have laser or freezing treatment. This is a simple procedure usually performed under a local anaesthetic. Often, however, an operation to repair the hole in the retina will be needed. This does not usually cause pain, but the eye will be sore and swollen afterwards. You will usually need to stay in hospital for two or three days after the operation.
A day after the operation, you will be given eye drops to reduce the swelling and prevent infection. It is important not to rub the eye while it heals, which will usually take two to six weeks.
It can take many months for vision to improve after surgery and in some cases you may experience some degree of permanent vision loss, but not complete blindness. Your ophthalmologist can advise you about any activities you may need to avoid while you recover. The amount of vision that can be successfully restored depends, for the most part, on how much of the retina was detached and for how long.