Detached retina (retinal detachment)

What is a detached retina?

A detached retina is when the light-sensitive layer of tissue lining the back of your eye (the retina) comes loose from its normal position. It's usually painless, but it needs urgent treatment, since it can permanently affect your sight if it isn't repaired quickly.

Symptoms of a detached retina

A detached retina doesn't cause pain, but it does cause sudden changes to your vision that need urgent attention. Symptoms include:

• a sudden increase in floaters (small dots, spots or squiggly lines drifting across your vision)
• flashes of light in your eye, lasting anywhere from a split second to a few seconds
• a dark shadow or curtain spreading across your field of vision, usually starting at the edges
• blurred vision, or a sudden change in vision in one eye.

Floaters and flashes are common and don't always mean you have a detached retina, but a sudden increase or change should always be checked urgently by an eye specialist, since there's no other way to tell what's causing them.

Causes of a detached retina and risk factors

In most cases, a detached retina happens because of changes to the jelly-like substance (vitreous) that fills your eye as you get older. This is called posterior vitreous detachment (PVD). It's not clear why PVD leads to a tear or detachment in some people, and there's nothing you can do to prevent it.

You're more likely to develop a detached retina if you:

• are short-sighted (myopic)
• have had an eye operation, such as cataract surgery
• have had an eye injury
• have had a retinal detachment in your other eye
• have diabetes affecting your eyes (diabetic retinopathy), or another condition that causes inflammation inside the eye
• have a family history of retinal detachment, although this is a less common cause than ageing or injury.

Are there different types of retinal detachment?

There are three main types of retinal detachment, each with a different cause.

Rhegmatogenous detachment is the most common type. A tear or hole develops in the retina, often because the shrinking vitreous pulls on it, allowing fluid to leak through and collect behind the retina, which then lifts away from the back of the eye.

Tractional detachment happens when scar tissue forms on the surface of the retina and pulls it away from the back of the eye. This is usually linked to poorly controlled diabetes, or can follow previous eye surgery.

Exudative detachment is the rarest type. Fluid collects behind the retina without any tear or hole, usually because of inflammation, a tumour, or leaking blood vessels within the eye.

How is a detached retina diagnosed?

An optometrist or eye doctor can usually diagnose a detached retina during an eye examination. They'll put drops in your eye to widen (dilate) your pupil, then examine your retina using a special lens or light.

They may also take photographs of the back of your eye, or use an ultrasound scan, to get a clearer picture of the retina, particularly if bleeding inside the eye is making it difficult to see clearly.

How is a detached retina treated?

Treatment depends on whether the retina has fully detached or only torn.

Non-surgical treatment

If a retinal tear is caught before the retina fully detaches, it can sometimes be sealed during an outpatient appointment using laser treatment or cryotherapy (freezing). Both create a small, controlled scar around the tear that holds the retina in place and can prevent it detaching further.

Surgical treatment

Once the retina has detached, surgery is needed to reattach it and prevent permanent vision loss. Your surgeon may use one technique or combine more than one.

Pneumatic retinopexy involves injecting a small gas bubble into your eye to push the retina back into place, usually combined with laser or cryotherapy to seal the tear. The bubble absorbs by itself over time.

Scleral buckling involves attaching a small band of silicone around the outside of your eye, permanently, to gently push the wall of the eye inwards so it presses against the retina and holds it in place. You won't usually see or feel it afterwards.

A vitrectomy involves removing the vitreous jelly from inside your eye and replacing it with a bubble of gas or oil, which gives your surgeon access to reattach the retina. Depending on the type used, a gas bubble usually absorbs over 10–14 days or 6–8 weeks, while oil needs to be removed in a separate operation later on.

Surgery is usually done under local anaesthetic, so you're awake but your eye is numbed, though a general anaesthetic can be used instead. It's usually done as a day case, so you shouldn't need to stay in hospital overnight.

You may be asked to hold your head in a particular position, sometimes for up to seven days, to help a gas bubble keep the retina in place while it heals. You won't be able to fly while you have a gas bubble in your eye, since the change in air pressure can cause it to expand and damage your eye.

Recovery varies, but as a general guide, for 2–6 weeks after surgery your vision may be blurry and your eye sore or red (paracetamol can help), and you may need time off work and be unable to drive. Most people eventually return to all their normal activities, though your vision may keep improving, and your retina keep healing, for a year or more.

When should I get help?

Get help from NHS 111, or go to an eye casualty department, if you develop new floaters, flashes of light, a dark curtain or shadow in your vision, or sudden blurring. The sooner a detached retina is treated, the better your chances of keeping your sight, ideally within 48 hours of your symptoms starting.

You can get a detached retina more than once, including in your other eye, so seek help again straight away if your symptoms come back after treatment.