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!!!!!!!!!!!!!!.