proptosis
proptosis
It is defined as forward displacement of
the eyeball beyond the orbital margins.
Though the word exophthalmos (out
eye) is synonymous with it; but
somehow it has become customary to
use the term exophthalmos for the
displacement associated with thyroid
disease.
CLASSIFICATION
Proptosis can be divided into following clinical
groups:
1. Unilateral proptosis
2.Bilateral proptosis
3. Acute proptosis
4. Intermittent proptosis
5. Pulsating proptosis
ETIOLOGY
Important causes of proptosis in each
clinical group are listed here:
A. Causes of unilateral proptosis
include:
1. Congenital conditions. These include:
○ Dermoid cyst,
○ congenital cystic eyeball, and orbital teratoma.
2. Traumatic lesions
3. Inflammatory lesions
4. Circulatory disturbances and vascular
lesions
5. Cysts of orbit
6. Tumours of the orbit
7. Mucoceles of paranasal sinuses
B. Causes of bilateral proptosis
include 1. Developmental anomalies of the skull:
craniofacial dysostosis e.g., oxycephaly (tower
skull).
2. Osteopathies
3. Inflammatory conditions: Mikulicz’s syndrome
and late stage of cavernous sinus thrombosis.
4. Endocrinal exophthalmos (eg;thyrotoxicosis).
5. Tumours: These include symmetrical
lymphoma or lymphosarcoma,
6. Systemic diseases: Histiocytosis,
systemicamyloidosis, xanthomatosis and
Wegener’s granulomatosis, thyroid diseases
C. Causes of acute proptosis.
It develops with extreme rapidity
(sudden onset). Its common causes are
: orbital emphysema, fracture of the
medial orbital wall, orbital haemorrhage
and rupture of ethmoidal mucocele.
D. Causes of intermittent
proptosis:
This type of proptosis appears and
disappears of its own, Its common
causes are: orbital varix, periodic orbital
oedema, recurrent orbital haemorrhage
and highly vascular tumours.
E. Causes of pulsating proptosis: It is caused by pulsating vascular lesions
such as caroticocavernous fistula and saccular aneurysm of ophthalmic artery.
Pulsating proptosis also occurs due to transmitted cerebral pulsations in conditions associated with deficient orbital roof. These include congenital meningocele or meningoencephalocele, neurofibromatosis and traumatic or operative hiatus.
Investigation of a case of
proptosis
I. Clinical evaluation
(A) History. It should include: age of
onset, nature of onset, duration,
progression, chronology of orbital signs
and symptoms.
(B) Local examination. It should be
carried out as follows:
1. Inspection. (i) To differentiate
proptosis from pseudoproptosis which is
seen in patients with buphthalmos, axial
high myopia, retraction of upper lid and
enophthalmos of the opposite eye. (ii) to
ascertain whether the proptosis is
unilateral or bilateral; (iii) to note the
shape of the skull;and (iv) to observe
whether proptosis is axial or eccentric.
2. Palpation It should be carried out for retrodisplacement of globe to know compressibility of the tumour, for orbital thrill, for any swelling around the eyeball, regional lymph nodes and orbital rim.
3. Auscultation It is primarily of value in searching for abnormal vascular communications that generate a bruit, such as caroticocavernous fistula.
4. Transillumination. It is helpful in
evaluating anterior orbital lesions.
5. Visual acuity. Orbital lesions may
reduce visual acuity by three
mechanisms: refractive changes due to
pressure on back of the eyeball, optic
nerve compression and exposure
keratopathy.
6. Pupil reactions. The presence of
Marcus Gunn pupil is suggestive of optic
nerve compression.
7. Fundoscopy. It may reveal venous
engorgement, haemorrhage,
papilloedema and optic atrophy.
Choroidal folds and opticociliary shunts
may be seen in patients with
meningiomas.
8. Ocular motility It is restricted in
thyroid ophthalmopathy, extensive
tumour growths and neurological deficit.
9. Exophthalmometry It measures protrusion of the apex of cornea from the outer orbital margin (with the eyes looking straight ahead).
Normal values vary between 10 and 21 mm and are symmetrical in both eyes.
A difference of more than 2 mm between the two eyes is considered significant.
The simplest instrument to measure proptosis is Luedde’s exophthalmometer . the Hertel’s exophthalmometer ( is the most commonly used instrument.
Its advantage is that it measures the two eyes simultaneously.
C) Systemic examination. A thorough
examination should be conducted to rule
out systemic causes of proptosis such as
thyrotoxicosis, histiocytosis, and primary
tumours elsewhere in the body
(secondaries in orbits).
Otorhinolaryngological examination is
necessary when the paranasal sinus or a
nasopharyngeal mass apears to be a
possible etiological factor.
II. Laboratory investigations
These should include: Thyroid function tests,
Haematological studies (TLC, DLC, ESR, VDRL test),
…. Casoni’s test (skin test to rule out hydatid cyst),.
Stool examination for cysts and ova, and
Urine analysis for Bence Jones proteins for
multiple myeloma.
III. Imaging Technique
(A) Non-invasive techniques
1. Plain X-rays.
2. Computed tomography scanning
3. Ultrasonography
4. Magnetic resonance imaging (MRI).
(B) Invasive procedures
1. Orbital venography
2. Carotid angiography.
3. Radioisotope studies.
IV. Histopathological studies ;The
exact diagnosis of many orbital lesions
cannot be made without the help of
histopathological studies,which can be
accomplished by following techniques.
1. Fine-needle aspiration biopsy
(FNAB).
2. Incisional biopsy.
3. Excisional biopsy.
MANAGEMENT OF PROPTOSIS REMOVE THE UNDERLYING CAUSES!!!!!!!!!!!!!!.