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Papilloedema is swelling that develops where the optic nerve enters the eye as a result of increased pressure inside the skull. The optic nerve carries visual information from the eye to the brain. When pressure inside the brain increases, it can be transmitted along the optic nerve sheath and cause swelling at the optic nerve head. Papilloedema usually occurs in both eyes, although the degree of swelling may differ between the eyes in some patients. The condition may go unnoticed during the early stages because visual acuity may remain unaffected. Assessment should be carried out without delay to identify the underlying cause and reduce the risk of vision loss.
How Does Papilloedema Develop?
The brain and spinal cord are surrounded by a fluid called cerebrospinal fluid. Intracranial pressure may increase when the production, circulation or absorption of this fluid is disrupted. Masses within the brain, haemorrhages and certain vascular problems may also cause increased pressure. The increased pressure is transmitted to the sheaths surrounding the optic nerve. This may affect cellular transport and fluid balance at the optic nerve head. An elevated optic disc with blurred margins during a fundus examination is among the findings associated with this process.
Is Every Swollen Optic Disc Papilloedema?
Not every swelling of the optic nerve head is considered papilloedema. The term papilloedema is specifically used for optic disc swelling caused by increased intracranial pressure. Optic neuritis, vascular occlusions or other optic nerve disorders may also cause disc swelling. Structural features such as optic disc drusen may give the appearance of swelling without true oedema in some people. This condition is considered pseudopapilloedema. A definitive distinction is made by assessing the eye examination and the necessary imaging findings together.
What Causes Papilloedema?
The causes of papilloedema are associated with various neurological or systemic conditions that increase intracranial pressure. Brain tumours and abscesses may occupy space within the skull and cause increased pressure. Hydrocephalus, in which the circulation of cerebrospinal fluid is impaired, may also be associated with papilloedema. Infections such as meningitis and intracranial haemorrhages are other important causes. Obstruction of the veins in the brain may also increase intracranial pressure. In some patients, increased pressure develops even though imaging does not reveal an obvious mass.
The main conditions that may be associated with papilloedema include:
- Intracranial tumours or abscesses.
- Hydrocephalus.
- Intracranial haemorrhages.
- Meningitis and other infections.
- Blood clot formation in the cerebral veins.
- Idiopathic intracranial hypertension.
- Increased pressure associated with certain medications.
Idiopathic Intracranial Hypertension
Idiopathic intracranial hypertension is an increase in intracranial pressure without an identifiable brain mass or another explanatory cause. Previously also known as pseudotumour cerebri, this condition may occur in different age groups. Excess weight and certain hormonal characteristics are important when assessing risk in some patients. Headaches, transient visual obscurations and hearing a sound in the ear that corresponds with the pulse may occur. Double vision may be associated with involvement of the nerves that control eye movements. Diagnosis is made using imaging findings and an assessment of cerebrospinal fluid under appropriate conditions.
What Are the Symptoms of Papilloedema?
The symptoms of papilloedema may vary according to the level of intracranial pressure and the underlying condition. Headache is one of the common symptoms and may be more noticeable in the morning in some patients. Nausea, vomiting and temporary blurred vision may also occur. Brief visual obscurations may sometimes be noticed when changing head position. Double vision or narrowing of the visual field may develop. It is also possible to have no noticeable vision problems during the early stages.
Symptoms that may occur with papilloedema include:
- Persistent or progressively worsening headache.
- Nausea and vomiting.
- Brief visual obscurations.
- Temporary blurred vision.
- Double vision.
- Narrowing of the visual field.
- Hearing a sound in the ear that corresponds with the pulse.
- Reduced vision in advanced cases.
How Does Papilloedema Affect Vision?
Central visual acuity may remain normal during the early stages of papilloedema. The person may therefore believe that there is no significant problem with their eyes. Despite this, subtle changes in the visual field may develop. When increased intracranial pressure continues for an extended period, the optic nerve fibres may become damaged. In advanced cases, narrowing of the visual field and permanent vision loss may occur. The cause and duration of the increased pressure should be assessed together to protect vision.
How Is Papilloedema Diagnosed?
Papilloedema is usually identified during a fundus examination when the optic disc margins appear blurred and the optic nerve head appears elevated. However, the underlying cause cannot be determined by looking at the fundus image alone. Visual acuity and visual field tests provide information about the extent to which the optic nerve has been affected. Optical coherence tomography may help monitor swelling at the optic nerve head. Blood pressure, neurological symptoms and medications being used should also be assessed. When necessary, the assessment is carried out together with relevant specialties such as neurology and neurosurgery.
Methods that may be used during the diagnostic process include:
- A comprehensive fundus examination.
- Visual field testing.
- Optical coherence tomography.
- Magnetic resonance imaging of the brain.
- Computed tomography.
- Imaging of the cerebral veins.
- Lumbar puncture in suitable patients.
Why Is Brain Imaging Important?
When papilloedema is detected, conditions that may increase intracranial pressure should be investigated. Magnetic resonance imaging of the brain may help assess masses, hydrocephalus or other structural changes. Computed tomography may be used when necessary. Vascular imaging methods may also be considered to investigate obstruction of the cerebral veins. The order in which examinations are performed is determined according to the patient's symptoms and general condition. Patients with urgent neurological findings should be assessed without delay.
When Is a Lumbar Puncture Performed?
A lumbar puncture is a procedure in which cerebrospinal fluid is collected from the lower back and its pressure is measured. This method may help assess increased intracranial pressure in some patients. When necessary, the collected fluid is also examined for infection or other conditions. However, lumbar puncture is not performed directly in every patient before brain imaging. A space-occupying lesion inside the skull or another condition that may make the procedure unsafe should first be ruled out. Whether the procedure is required is determined according to the neurological assessment and imaging findings.
How Is Papilloedema Treated?
Treatment of papilloedema is directed at the underlying cause of increased intracranial pressure rather than the swelling of the optic nerve itself. Cause-specific treatment is provided for patients with an intracranial mass, infection, haemorrhage or vascular occlusion. Conditions such as hydrocephalus may require procedures to regulate the circulation of cerebrospinal fluid. In idiopathic intracranial hypertension, pressure-lowering medications and weight management may be considered in suitable patients. More advanced surgical options may be considered if the risk of vision loss is high. The treatment plan is created through assessments by ophthalmology, neurology and any other required specialties.
Medications intended to reduce cerebrospinal fluid may be used in some patients. If vision is deteriorating rapidly, surgery involving the optic nerve sheath or procedures that provide fluid drainage may be considered. Different treatment methods involving the cerebral veins may also be considered in selected cases. The same medication or surgical method is not suitable for every patient. Using diuretic medication or changing an existing treatment without medical guidance may be harmful. The appropriate approach is determined according to the underlying condition and its effect on vision.
How Is Follow-up Planned?
Visual acuity and the visual field should be monitored regularly in patients diagnosed with papilloedema. Swelling at the optic nerve head may be monitored through fundus examinations and the necessary imaging methods. A reduction in headaches after treatment does not mean that the risk to vision has been completely eliminated. Changes in the visual field may continue in some patients even if their symptoms improve. The frequency of follow-up is determined according to the severity of papilloedema and the underlying cause. Regular assessment helps identify permanent optic nerve damage at an early stage.
Which Symptoms Require Urgent Assessment?
Severe or progressively worsening headaches, repeated vomiting and newly developed visual obscurations may require urgent assessment. Sudden vision loss, double vision or significant visual field loss are also important. These symptoms may also be associated with neurological conditions other than papilloedema. Emergency medical care should be sought, particularly if symptoms such as altered consciousness, loss of strength or speech impairment are also present. A routine examination appointment should not be awaited when papilloedema is suspected. You can contact me using the contact details on my website to arrange non-urgent follow-up and monitoring.
