Papilloedema: symptoms, causes and what happens next

East Kent Hospitals says that for most people the nerve swelling itself has no effect, which is why it is often found at an eye test rather than reported as a complaint. The symptoms that do occur come from the raised pressure, and the leaflet gives headaches and vomiting as examples.

Cambridge University Hospitals gives a fuller list for idiopathic intracranial hypertension (IIH), the most common condition it describes behind a swollen optic nerve: severe throbbing headaches that are often constant, worse in the morning and made worse by straining or coughing, double vision and other vision changes, pulsating tinnitus, tiredness, neck pain, mood and behaviour changes and difficulty sleeping.

The BNSSG referral pathway lists the features that make clinicians more concerned about raised pressure: headache that is worse at night, on waking, or on coughing or moving the head; changes in mental state such as lethargy or irritability; vomiting; and changes in the pupils or eye movements. It says the swelling can cause blurred vision, and that damage may result in permanent visual impairment if left untreated.

• Often no symptoms from the swelling itself.

• Headaches, sometimes worse on waking or on coughing or straining.

• Vomiting, double vision or other changes in vision.

• Pulsating tinnitus, neck pain, tiredness or changes in mood in IIH.

The optic nerve carries visual signals from the eye to the brain. University Hospitals Coventry and Warwickshire (UHCW) describes it as a collection of over one million nerve cells, with the head of the nerve as it enters the eye called the optic disc. Papilloedema is swelling of that part of the nerve, and the swelling is a sign of something else, not a disease on its own.

The BNSSG pathway makes a point of terminology: the term papilloedema refers specifically to optic disc swelling secondary to raised pressure inside the skull. Not all optic disc swelling is papilloedema, and careful history and examination are needed to separate it from other causes.

East Kent explains that when papilloedema is found it is important to look for the cause of the raised pressure and to assess whether vision is being affected. The swelling can be seen by looking at the back of the eye, which is why opticians and doctors find it during an eye examination.

Treatment depends on the cause, because the swollen disc is a sign rather than the disease. East Kent says that if an MRI scan finds what is causing the pressure, this is discussed with a specialist team; that if the MRI is normal and an eye specialist confirms that true papilloedema is not present, no further action is needed; and that IIH normally responds to treatment with tablets.

Cambridge says IIH treatment can include weight loss if overweight, which often relieves symptoms altogether, and medicines such as acetazolamide and topiramate to reduce production of cerebrospinal fluid, a diuretic (furosemide), steroids (prednisolone) and painkillers for headaches. All medicines carry a risk of side effects, and surgery is considered a last resort for chronic IIH. The trust says it is important to detect IIH early and start treatment to prevent permanent loss of vision.

IIH UK, the charity for people with the condition, says IIH is rare, affects around 1 to 3 in every 100,000 people, and can cause persistent headaches, visual changes and, in severe cases, permanent sight loss if left untreated.

East Kent lists the ways pressure in the head can rise. Some are serious but rare, and the next steps by the medical team are to confirm whether there are any signs of more serious problems.

• Too much cerebrospinal fluid (CSF) in the brain, either because too much is produced or because it is not absorbed fast enough. IIH is the condition in which this happens without any underlying cause.

• An obstruction to the flow of CSF.

• Something taking up more space alongside the brain, such as a bleed or a tumour.

• Swelling of the brain, for example from a head injury.

• An abnormality of the skull that stops it growing as the brain grows.

• Malignant (very high) blood pressure, which the BNSSG pathway says can lead to optic disc swelling and is checked for in every person with suspected papilloedema.

Not every swollen-looking disc is papilloedema. UHCW explains that optic nerve drusen are deposits of protein and calcium in the optic nerve found in 1 to 2% of the population, usually in both eyes. They make the nerve look lumpy or raised, which may result in an optician referring the person to hospital. The aim of the hospital assessment is to tell the two apart.

East Kent’s leaflet, written for parents, describes the usual steps for children and young people: an eye doctor examines the eye to confirm the condition, a paediatric doctor looks for signs of problems with the nerves or brain, and an urgent MRI scan of the brain is normally arranged. If the scan is normal, the team considers a lumbar puncture, which it describes as the only way to diagnose IIH because it will not be seen on an MRI scan.

It says that if there are no headaches or other symptoms and the MRI is normal, the team may hold off the lumbar puncture until the eye specialist has seen the child, usually within 6 weeks, to assess whether the appearance is true papilloedema. Cambridge describes a similar pathway for suspected IIH: the doctor first rules out other causes, refers to an ophthalmologist for a detailed eye examination and may involve a neurologist, CT or MRI scans, blood tests and a lumbar puncture to measure the pressure and test the CSF.

Both leaflets are written for children and young people, so details of timing and tests may differ for adults. Whoever refers you will explain what applies in your case.

If an optician or doctor tells you that your optic discs look swollen, treat the referral as important and attend promptly. East Kent says that early assessment is about both finding the cause and checking whether vision is being affected.

The BNSSG pathway, written for clinicians, says that patients with papilloedema and symptoms or signs of raised pressure should be admitted to hospital (via 999) for emergency investigation, and gives headache with vomiting, changes in mental state such as lethargy or irritability, and changes in the pupils as warning features. If you have a swollen disc and a severe or worsening headache, repeated vomiting, double vision or a change in how alert or settled you feel, treat this as an emergency and call 999 or go to A&E. For milder symptoms, contact your GP or NHS 111 the same day.

Sudden loss or change in vision, or a headache unlike any you have had, should always be assessed urgently whether or not you have had a swollen disc diagnosed.

The usual route is a referral from an optician or GP. The BNSSG pathway says patients with suspected papilloedema and no red flags are referred urgently to a neuro-ophthalmology service, and that primary care should not arrange imaging beforehand because that may cause delay and the decision is best made by the specialist. It also says all patients with true papilloedema need imaging or further specialist investigation, with urgency depending on the suspected cause.

East Kent describes children being referred by a GP or optician to a hospital eye team and a paediatric team, with an urgent MRI scan of the brain. Some people choose a private ophthalmology or neurology opinion for speed. In either setting the key tests, which are a detailed eye examination and brain imaging, are the same, and if a scan finds a significant cause, specialist neurological care will usually be needed.