PAPILLOEDEMA

The terms papilloedema and disc oedema look alike
and per se mean swelling of the optic disc. However,
arbitrarily the term ‘papilloedema’ has been reserved
for the passive disc swelling associated with
increased intracranial pressure which is almost always
bilateral although it may be asymmetrical. The term
‘disc oedema or disc swelling’ includes all causes of
active or passive oedematous swelling of the optic
disc.
Causes of disc oedema
1. Congenital anomalous elevation (Pseudopapilloedema)
2. Inflammations
Papillitis
Neuroretinitis
3. Ocular diseases
Uveitis
Hypotony
Vein occlusion
4. Orbital causes
Tumours
Graves’ orbitopathy
Orbital cellulitis
5. Vascular causes
Anaemia
Uremia
Anterior ischaemic optic neuropathy
6. Increased intracranial pressure
See causes of papilloedema
Etiopathogenesis of papilloedema
Causes. As discussed above, papilloedema occurs
secondary to raised intracranial pressure which may
be associated with following conditions:
1. Congenital conditions include aqueductal
stenosis and craniosynostosis.
2. Intracranial space-occupying lesions (ICSOLs).
These include brain tumours, abscess,
tuberculoma, gumma, subdural haemotoma and
aneurysms. The ICSOLs in any position excepting
medulla oblongata may induce papilloedema.
Papilloedema is most frequently associated with
tumours arising in posterior fossa, which obstruct
aqueduct of Sylvius and least with pituitary
tumours. Thus, the ICSOLs of cerebellum,
midbrain and parieto-occipital region produce
papilloedema more rapidly than the mass lesions
of other areas. Further, the fast progressing lesions
produce papilloedema more frequently and acutely
than the slow growing lesions.
3. Intracranial infections such as meningitis and
encephalitis may be associated with papilloedema.
4. Intracranial haemorrhages. Cerebral as well as
subarachnoid haemorrhage can give rise to
papilloedema which is frequent and considerable
in extent.
5. Obstruction of CSF absorption via arachnoid
villi which have been damaged previously.
6. Tumours of spinal cord occasionally give rise to
papilloedema.
7. Idiopathic intracranial hypertension (IIH) also
known as pseudotumour cerebri,is an important
cause of raised intracranial pressure. It is a poorly
understood condition, usually found in young
obese women. It is characterised by chronic
headache and bilateral papilloedema without any
ICSOLs or enlargement of the ventricles due to
hydrocephalus.
8. Systemic conditions include malignant
hypertension, pregnancy induced hypertension
(PIH) cardiopulmonary insufficiency, blood
dyscrasias and nephritis.
9. Diffuse cerebral oedema from blunt head trauma
may causes papilloedema
Unilateral versus bilateral papilloedema. Disc
swelling due to ocular and orbital lesions is usually
unilateral. In majority of the cases with raised
intracranial pressure, papilloedema is bilateral.
However, unilateral cases as well as of unequal
change do occur with raised intracranial pressure. A
few such conditions are as follows:
1. Foster-Kennedy syndrome. It is associated with
olfactory or sphenoidal meningiomata and frontal
lobe tumours. In this condition, there occurs
pressure optic atrophy on the side of lesion and
papilloedema on the other side (due to raised
intracranial pressure).
2. Pseudo-Foster-Kennedy syndrome. It is
characterised by occurrence of unilateral
papilloedema associated with raised intracranial
pressure (due to any cause) and a pre-existing
optic atrophy (due to any cause) on the other
side.
Pathogenesis. It has been a confused and
controversial issue. Various theories have been put
forward and discarded from time to time. Till date,
Hayreh’s theory is the most accepted one. It states
that, ‘papilloedema develops as a result of stasis of
axoplasm in the prelaminar region of optic disc, due
to an alteration in the pressure gradient across the
lamina cribrosa.’
Increased intracranial pressure, malignant
hypertension and orbital lesions produce disturbance
in the pressure gradient by increasing the tissue
pressure within the retrolaminar region. While, ocular
hypotony alters it by lowering the tissue pressure
within the prelaminar area.
Thus the axonal swelling in prelaminar region is
the initial structural alteration, which in turn produces
venous congestion and ultimately the extracellular
oedema. This theory discards the most popular view
that the papilloedema results due to compression of
the central retinal vein by the raised cerebrospinal
fluid pressure around the optic nerve.
Evolution and recovery. Papilloedema usually
develops quickly, appearing within 1-5 days of raised
intracranial pressure.
In cases with acute subarachnoid haemorrhage it
may develop even more rapidly (within 2-8 hours).
However, recovery from fully developed papilloedema
is rather slow. It takes about 6-8 weeks to subside
after the intracranial pressure is normalised.
Clinical features
[A] General features. Patients usually present to
general physicians with general features of raised
intracranial pressure. These include headache,
nausea, projectile vomiting and diplopia. Focal
neurological deficit may be associated.
[B] Ocular features. Patients may give history of
recurrent attacks of transient blackout of vision
(amaurosis fugax). Visual acuity and pupillary
reactions usually remain fairly normal until the late
stages of diseases when optic atrophy sets in.
Clinical features of papilloedema can be described
under four stages: early, fully developed, chronic and
atrophic.
1. Early (incipient) papilloedema
Symptoms are usually absent and visual acvity is
normal.
Pupillary reactions are normal.
Ophthalmoscopic features of early papilloedema
are (Fig. 12.11A): (i) Obscuration of the disc
margins (nasal margins are involved first followed
by the superior, inferior and temporal) (ii) Blurring
of peripapillary nerve fibre layer. (iii) Absence of
spontaneous venous pulsation at the disc
(appreciated in 80% of the normal individuals).
(iv) Mild hyperaemia of the disc. (v) Splinter
haemorrhages in the peripapillary region may be
present.
Visual fields are fairly normal.
2. Established (fully developed) papilloedema
Symptoms. Patient may give history of transient
visual obscurations in one or both eyes, lasting
a few seconds, after standing. Visual acuity is
usually normal,
Pupillary reaction remain fairly normal,
Ophthalmoscopic features (Fig. 12.11B): (i)
Apparent optic disc oedema is seen as its forward
elevation above the plane of retina; usually up to
1-2 mm (1 mm elevation is equivalent to +3
dioptres). (ii) Physiological cup of the optic disc
is obliterated. (iii) Disc becomes markedly
hyperaemic and blurring of the margin is present
all-around. (iv) Multiple soft exudates and
superficial haemorrhages may be seen near the
disc. (v) Veins becomes tortuous and engorged.
(vi) In advanced cases, the disc appears to be
enlarged and circumferential greyish white folds
may develop due to separation of nerve fibres by
the oedema. (vii) Rarely, hard exudates may radiate
from the fovea in the form of an incomplete star.
Visual fields show enlargement of blind spot.
3. Chronic or long standing (vintage) papilloedema
Symptoms. Visual acuity is variably reduced
depending upon the duration of the papilloedema.
Pupillary reactions are usually normal
Ophthalmoscopic features (Fig. 12.11C). In this
stage, acute haemorrhages and exudates resolve,
and peripapillary oedema is resorbed. The optic
disc gives appearance of the dome of a champagne cork. The central cup remains
obliterated. Small drusen like crystalline deposits
(corpora amylacea) may appear on the disc
surface.
Visual fields. Blind spot is enlarged and the
visual fields begin to constrict.
4. Atrophic papilloedema
Symptoms. Atrophic papilloedema develops after
6-9 months of chronic papilloedema and is
characterized by severely impaired visual acuity.
Pupillary reaction. Light reflex is impaired.
Ophthalmoscopic features (Fig. 12.11D)
It is characterised by greyish white discoloration
and pallor of the disc due to atrophy of the neurons
and associated gliosis. Prominence of the disc
decreases in spite of persistent raised intracranial
pressure. Retinal arterioles are narrowed and veins
become less congested. Whitish sheathing develops
around the vessels.
Visual fields. Concentric contraction of peripheral
fields becomes apparent as atrophy sets in.
Differential diagnosis
Papilloedema should be differentiated from pseudopapilloedema
and papillitis. Pseudopapilloedema is
a non-specific term used to describe elevation of the
disc similar to papilloedema, in conditions such as
optic disc drusen, hypermetropia, and persistent
hyaloid tissue. The differentiating points between
papilloedema, papillitis and pseudopapilloedema
(pseudopapillitis) due to hypermetropia are
enumerated in Table 12.2.
Treatment and prognosis
It is a neurological emergency and requires immediate
hospitalisation. As a rule unless the causative disease
is treatable or cerebral decompression is done, the
course of papilloedema is chronic and ultimate visual
prognosis is bad.
Feature Papilloedema Papillitis Pseudopapillitis
1. Laterality Usually bilateral Usually unilateral May be unilateral
or bilateral
2. Symptoms
(i) Visual acuity Transient Marked loss of Defective vision
attacks of blurred vision of depending upon
vision sudden onset the degree of
Later vision refractive error
decreases due to
optic atrophy
(ii) Pain and tenderness Absent May be present Absent
with ocular movements
3. Fundus examination
(i) Media Clear Posterior Clear
vitreous haze
is common
(ii) Disc colour Red and juicy Marked Reddish
appearance hyperaemia
Disc margins Blurred Blurred Not well defined
Disc swelling 2-6 dioptres Usually not Depending upon the
more than degree of
3 dioptres hypermetropia
(iii) Peripapillary oedema Present Present Absent
(iv) Venous engorgement More marked Less marked Not present
(v) Retinal haemorrhages Marked Usually not present Not present
(vi) Retinal exudates More marked Less marked Absent
(vii) Macula Macular star may be Macular fan may be Absent
present present
4. Fields Enlarged Central scotoma No defect
blind spot more for colours
5. Fluorescein angiography Vertical oval Minimal No leakage of dye
pool of dye leakage of dye
due to leakage