papilledema

Papilledema is a, non-inflammatory passive swelling of the optic disc, produced by raised intra-cranial tension (ICT). It occurs as a result of interrupted axoplasmic flow in the optic nerve due to transmitted elevated cerebrospinal fluid pressure in the subarachnoid space around it. This in turn causes venous congestion. ·

. Papilledema (due to raised ICT) is one of the causes of "disc-edema", and they are not synonymous. The other causes of 'disc-edema' are mentioned later. Pathology is same in papilledema and disc-edema. The above definition is for the sake of convenience.

. Generally, unilateral causes of 'disc-edema' should be considered to be due to a local inflammation, vascular disorders, or compressive lesions in the orbit. ·

. Unilateral papilledema with optic atrophy on the other side, suggests a frontal lobe tumor or olfactory meningioma of the opposite side - the Foster-Kennedy Syndrome.

. In children below 2 years, papilledema is usually rarer.

. As a rule, papilledema does not develop

- if the optic nerve has already become atrophic,
- in congenital absence of arachnoidal sheath
- in opto chiasmatic arachnoiditis or other forms of basal meningitis due to tuberculosis etc.

Any intra-cranial tumor may induce papilledema. It is most evident with tumors in the posterior fossa which obstruct the aqueduct of Sylvius, and least with pituitary tumors. The site of the tumors is, thus, more important than its nature, its size and rate of growth.

Causes of papilledema

1. Pseudo-tumor cerebri.
2. Space-occupying intracranial lesions.
3. Microbial infection: meningitis, encephalitis.
4. Hypertensive encephalopathy
5. Intracranial vascular lesions: sub-arachnoid hemorrhage, sagittal sinus thrombosis, etc.
6. Head-injury - long standing contusions, carotid-cavernous fistula
7. Metabolic disorders: Addison's disease, , hypo-parathyroidism, etc.
8. Blood dyscrasias : leukemia, polycythemia, etc.
9. Choroidal plexus tumour by hypersecretion.
10. Miscellaneous; serum sickness, status epilepticus, sarcoidosis etc.

A. General symptoms :

1. Headache - bifrontal/occipitonuchal, worse in the morning and by coughing or straining. It may be less in early papilledema.
2. Vomiting without nausea and without loss of appetite.
3. Focal neurological deficit with changes in level of consciousness may be present.

B. Ocular symptoms:

1. Visual acuity remains fairly normal or decreased in established papilloedema and grossly affected in atrophic stage.
2. Amaurosis fugax - a transient, black out of vision for few seconds may be present in some patients usually in late stages due to enormous increase ICT.

Signs

1. Pupillary reactions are normal, until secondary optic atrophy has set in.
2. Ophthalmoscopy: The Ophthalmoscopic features in the different stages of the disease are:

a) Early papilledema:

Earliest change is disc hyperemia and dilated

capillaries. Blurring of disc margins, spontaneous

venous pulsation is absent (does not confirm

papilledema because it is not present in

20 % of normal population.)

Splinter hemorrhages at or just off the disc-margin.

(b) Established papilledema:

Disc margins become indistinct and central

cup is obliterated. Disc surface is elevated

above the retinal plane (more than + 3D (1mm) with direct ophthalmoscope). Peripapillary oedema.

[Paton's lines, present temporal to the disc].

Venous engorgement . Flame-shaped

hemorrhages and 'cotton-wool' spots around

the disc. Hard exudates in radiating pattern

around the macula, [macular star]

(c) Chronic papilledema or Vintage papilledema:

Disc edema resolves, but margins are blurred

Hemorrhagic and exudative components

gradually resolve. Optic disc appears pale like

a champagne cork. White spots - corpora amylacea

may be seen on the disc.

d) Atrophic papilledema

.Peripapillary retinal

vessels are attenuated

and sheathed.

.Dirty-white appearance

of the optic disc, due to

reactive gliosis - leading

to secondary optic

atrophy.


Normal F.F.A	Arterial phase of a F.F.A. shows marked Dilatation of the peripapillary capillaries	Venous phase of F.F.A shows leakage of dye from the vessels

Field changes

1. In early stage - there is no field defect.
2. In established stage - there is enlargement of the blind spot.
3. In chronic stage - there is associated peripheral constriction of the visual field with appearance of nerve-fiber bundle defects.
4. Finally, there is total loss of visual field.

Papilledema usually develops slowly but sometimes it may develop rapidly even in eight hours (subarachnoid hemorrhage). With timely and appropriate intervention, early and established papilledema completely resolve in few days to few weeks with total recovery of visual acuity and full visual fields.

Fundus Fluorescein Angiography[F.F.A.] is a useful tool in differentiating true and pseudopapilledema. Clinical picture is important for diagnosis.

B-Scan Biometry may be done when media is obscured to detect optic nerve head elevation.

Differences between papilledema and optic neuritis:

	Papilledema	Optic neuritis
1. History	headache and vomiting, initially no visual symptom.	sudden loss of vision; H/o fever, or upper respiratory tract infection.
2. Laterality	usually bilateral.	usually unilateral.
3. Visual acuity.	remains normal until late stage	severely reduced (6/60 or less)
4. Pain or tenderness of eyeball	absent.	may be present
5. Pupill	normally reacting	relative afferent pupillary defect (Marcus-Gunn's pupil).
6. Disc swelling	more than + 3D elevation in established case.	usually +2D to +3D elevation
7. Hemorrhage and exudates	more in established case.	relatively less
8. Visual fields	enlargement of blind spot and later gradual peripheral constriction	central or centro-caecal scotoma.
9. CT-scan or MRI	intra-cranial space occupying lesion may be detected.	demyelinating disorder may be seen.

CLINICAL CONDITION	FUNDUS PICTURE
Hypertensive retinopathy	Attenuated arteries, less venous distention, heightened vascular reflexes, A/V crossing changes, disc swelling, hemorrhages, and exudates are more diffuse and peripheral too Ensure that the blood pressure is recording, preferably by yourself.]
Central retinal vein occlusion (CRVO)	Typically presents with retinal vein tortuosity, disc swelling and hemorrhages even in the peripheral fundus; cotton wool spots are uncommon in nonischaemic CRVO, but usually present in ischaemic CRVO
Papilledema with Preretinal hemorrhages	If front of the macula, it gives rise to severe If front of the macula, it gives rise to severe If front of the macula, it gives rise to severe located in syndrome), in infants of subdural haemorrhage
Medullated or myelinated nerve fibers	White -yellow spots seen superiorly and inferiorly, better appreciated with red free filter. It is extension of myelination to the prelaminar portion of optic nerve fibres.
Pseudopapilledema of hypermetropia	Usually in children with moderate to high hypermetropia; no enlargement of blind spot. [Cycloplegic refraction instruction is of help].
Pseudopapilledema due to optic disc drusen	Abnormal vascular architecture; enlargement of the blind spot; may cause field defects, sometimes hemorrhages; calcification is seen on ultrasound; Optic disc drusen are hyaline deposits in the optic nerve head, typically demonstrable on pre-injection photographs -autofluorescence.
Epipapillary membrane (Bergmeister's papilla)	If the atrophy of the hyaloid artery is incomplete and the epipapillary membrane in front of the disc is dense enough, it may be misinterpreted as disc edema.

DIFFERENTIAL DIAGNOSIS

Optic nerve meningioma	Typically middle-aged women; CT/MRI shows irregular margins of mass and excludes glioma (negative optic nerve in contrast to the density of the tumor)
Infiltrative optic neuropathy	Consider hematological disorders such as lymphoma or leukemia, but also granulomatous infiltrative diseases (e.g. sarcoid, tuberculosis)
Hypotony	Postoperatively or following trauma; IOP in the range of 2-4 mmHg; mild swelling of disc and macula
Juxtapapillary choroiditis	Focal chorioretinitis next and usually temporal to the disc; the rest of the disc remains normal; cells in the vitreous; unlikely to be confused with papilledema which always begins on the nasal margin of the disc.
uveitis	May cause disc swelling, especially intermediate uveitis
Leber's optic atrophy	Rare; swelling and macular star due to juxtapapillary capillary dilatation without leakage on fluorescein angiography; frequently begins as unilateral papillitis but becomes bilateral soon after; disc atrophy follows a few weeks later; diagnosis by molecular genetics.
Neuropathy (AION)	A manifestation of giant cell arteritis; patient usually over 70 years of age; visual loss is sudden and in some cases bilateral; the visual loss is frequently accompanied by periocular pain and preceding headaches, jaw claudication and polymyalgia rheumatica; raised erythrocyte sedimentation rate; raised C-reactive protein. A temporal artery biopsy is often done to confirm diagnosis in view of the need for long-term steroids
Nonarteritic AION	Patient is 45-65 years of age (about 10 years younger than arteritic AION), otherwise healthy or with a history of systemic vascular disease such as hypertension; loss of vision is sudden, rarely bilateral and some may have diffuse periocular pain but otherwise painless; the fellow eye commonly has a small or absent optic cup; prognosis for visual rehabilitation is better than in arteritic AION; one third of patients develop AION in the second eye within two years.

MANAGEMENT:

Papilledema could be VISION THREATENING.

Though there are exceptions, the public and all doctors are well aware about the importance of an eye examination in a case of headache when related to visual work or when associated with visual disturbances like diplopia and vomiting.

When often patients visit ophthalmologists for headache, we rule out other causes of headache like refractive errors, ocular muscle imbalance, ocular inflammation and glaucoma in them .Later we specifically look at the optic disc for obtaining an insight to the cause of headache.

When it is a case of disc edema it is extremely important to know whether it is true disc edema or pseudopapilledema and whether we are dealing with a case of optic neuritis .

A careful history like hypertension, diabetes etc., taking into account the various causes should be elicited. It should also include drug history particularly overdosage of Vitamin A, oral contraceptives, anti psychotics and others.

A complete and thorough eye check up comprising of visual acuity, visual fields, refraction (with appropriate cycloplegic especially in children, and slit lamp examination of the fundus, vitreous, and macula.

We should also have an idea of the stage of papilledema.

Investigations:

Floresin angiography (FFA) will show leak in cases of disc edema. This test should be carried out only when doubtful as it only helps in differentiating true from pseudo papilledema but not optic neuritis from papilledema.

When ophthalmic cause is ruled out, an opinion by neurologist or neurosurgeon should be sought to establish the diagnosis.

MRI of the brain with or without contrast should be carried out.

Guarded LP for C.S.F analysis or for reduction of ICT during dire emergency with manometry.

Treatment:

If papilledema is due to intracranial cause then anti-edema measures and the underlying causes have to be detected and treated ( ATT for tuberculoma, withdrawal of oral contraceptives, withdrawal of antipsychotics, removal of intracranial SOL or shunting of associated hydrocephalus etc).

In benign ICT-Acetazolamide is the drug of choice especially the sustained release variety due to lesser side effects because of BD,OD or AD dosage.Regular variety has to be consumed 4 times a day and side effects like paraesthesia are more and reduces the compliance.Liver function tests and hemogram have to be done periodically. Most of the cases spontaneously resolve but some of them may continue to have headache and visual loss. When visual deterioration is detected despite adequate antiedema measures, a lumbo-Peritoneal or subtemporal decompression is done by the neurosurgeon.

Lately, Optic Nerve Sheath Fenestration is preferred and carried out by a team of E.N.T, Neuro and eye surgeons.

Transnasal endoscopic approach would be preferable these days because both optic nerve sheaths can be tackled in the same sitting, and the Optic canal can be directly approached and optic nerve sheath visualized. The risks are infection and transfer of heat while working with burr in the vicinity of optic nerve. Continuous irrigation with water will be of help. Appropriate and adequate coverage with antibiotics will reduce chances of infection.

Role of ophthalmologist in management during the course of papilloedema:

Combined team work and clear communication and cooperation amongst the treating doctors will do wonders for the patient. A multidisciplinary approach in fact, is mandatory.

Ophthalmologist should guide the neurophysician and neurosurgeons by carefully monitoring the visual acuity and color vision by Ishihara chart. However when patient has difficulty in perceiving colors like before, he / she is asked to report promptly.

Visual fields monitoring–The appearance of overall peripheral constriction in serial autoperimetry provides more valuable information rather than the fundus picture for florid stage going into chronic and atrophic. Visual acuity decreases after that. It is not advisable to wait until then. It could denote the ?commencement of irreversible damage of the axons in the optic nerve –This should ring an alarm and the ophthalmologist should warn the neuro faculty about the urgency of the situation to step up the antiedema measures or intervene surgically at the earliest.

The author would like to share some of the experiences with illustrating cases.

Case – 1 :

A fourteen year old female with complaints of headache for one year had consulted several doctors. A diagnosis of depression was made. Having got no relief she finally came down to Chennai. The neuro surgeon subjected her to investigations.

MRI showed SOL. Stereotactic biopsy and HPE confirmed it as a case of tuberculoma.

Neuro ophthalmic examination showed –Right eye BCVA 6/18, 16/16 color vision ,disc edema and hyperemia with peripapillary sheathing and macular exudates and normal visual fields. In the left eye the vision was hand movements, and mild pallor of the disc.

The clinical picture remained status quo with ATT and anti-edema measures. Ethambutol was deliberately avoided for its neuro toxicity on the optic nerves.

After that the right eye began to show peripheral constriction despite IV mannitol etc. Only few days later the VA dropped from 6/18 to HM in RE and no PL in LE (picture B).

Repeat MRI showed decrease of perilesional edema .

Following discussions, a decision to perform trans nasal endoscopic decompression bilaterally in the same sitting under GA was made and carried out after explaining the risk of loosing vision and possibility of developing infection. At the end of the surgery CSF was let out.


Schematic picture	Peroperative picture-the optic nerve sheath being fenestrated.

Though vision improved transiently to CFCF for 2 days she was PL –VE for 2 months. She then regained vision in Right eye to 6/6, visual fields full and could pursue her normal life and studies.

Please Note:

ONSF can be also be done transconjunctivally by the ophthalmologist on one side at a time. Surgery on one optic nerve can reduce the pressure on contralateral optic nerve .But T / N endoscopy was adopted because as mentioned earlier it gives best access to the optic canal with least injury to the optic nerve. While tackling the outer part of canal bone with burr, the heat generated can be lessened by continued irrigation. The inner part should be curetted.

Mitomycin - C application on the optic nerve sheath before the fenestration has found to maintain the patency of the fistula.

ONSF is nowadays being recommended for secondary causes of increased ICT too.

(A) visual fields of RE

(B)visual fields of LE

Case - 2:

A 15 yr old female had headache for 1 yr .Ophthalmic examination was done elsewhere only at the beginning. Since it was found to be normal she used to take analgesics for relief. Finally when she developed vomiting and swaying gait, choroidal plexus tumor in the CPA was diagnosed .Despite surgical, radiotherapy and antiedema measures, her papilledema rapidly progressed and VA deteriorated drastically in a week’s time .She is now with only CFCF angular in RE and no PL in LE.

A word of caution!

If the SOL is a choroidal plexus tumor, the rate of progression of papilledema is alarmingly rapid and accelerated so much so that the patient goes from florid to chronic and atrophic in no time and looses vision unless timely and appropriate management are rendered.

During radiotherapy for various intracranial space occupying lesions, ICT can raise due to cerebral edema. Concomitant anti edema measures will reduce the burden on the optic nerves.

Case -3:

A 30 yr old female was referred as a case of papilledema by neuro surgeon for neuroophthalmic examination. Slit lamp examination showed mild bilateral anterior uveitis. Sarcoidosis was suspected and confirmed. The disc edema and uveitis responded to oral prednisolone. Topical steroids and cycloplegic drops were also given. It was a case of B / L disc edema due to sarcoidosis.

Case-4:

A 55 yr old male was referred to as a case of papilledema for neuroophthalmic examination. He was being investigated for brain metastasis at a tertiary care hospital. His BP was recorded normal all through out by staff nurse. He was previously treated for malignancy in the neck successfully. But fundus examination showed arterial attenuation in addition to disc edema. The BP was personally recorded and found to be 220/160 mm Hg. MRI and CSF analysis were normal. It was a case of grade - 4 HYPERTENSIVE RETINOPATHY.

Case-5:

A 40 yr old female was referred for headache to us by medical oncologist. She was a known case of Recurrent B Cell Lymphoma of the lungs. O / E she was found to have neovascular glaucoma in LE . Fundus examination revealed partial block of both central retinal arteries and optic discs had blurred margins. Media was hazy in Left Eye. There was both central retinal artery and vein occlusion in the Right Eye. A diagnosis of infiltrative optic neuropathy was made. MRI of brain showed optic nerve thickening correspondingly. Radiotherapy helped in resolution of edema and improvement of vision.

Case-6:

A 10 yr old girl complained of severe headache and vomiting for few days . Her ophthalmic examination showed papilloedema in both eyes. Careful history revealed that the child was taking Vitamin A 50000 IU everyday for the preceding 3 months though she was advised the treatment only for few days. Discontinuation of Vit A reversed papilledema and relieved the symptoms. Similarly 40 yr old female from Calcutta, a teacher by profession was found to have papilledema and benign ICT. The antidepressant she was taking was the causative factor. She was alright in few days after she stopped taking the medicine.