EVALUATION OF A CASE OF PROPTOSIS

Dr $amarth Mishra

Exophthalmos is defined in dorland’s medical dictionary as an “abnormal protrusion of the eyeball; also labeled as proptosis

Henderson reserves the use of the word exophthalmos for those cases of proptosis secondary to endocrinological dysfunction.

Exophthalmos: Term is reserved for describing prominence of eyes secondary to thyroid disease.

Proptosis: Signifies protrusion of eyeball due to all other causes.

Dystopia: Displacement of globe in coronal plane. It may coexist with proptosis or enophthalmos

Exorbitism: This is caused due to decrease in the volume of orbit causing the orbital contents to protrude forwards. Should be differentiated from proptosis/exophthalmos.

exorbitism

Objective of clinical evaluation:

-Determination of probable etiology -Plan of imaging. -Plan of management.

Pseudoproptosis needs to be ruled out as false impression of proptosis which may be given by:

-High myopia( unilateral enlargement of globe)-Unilateral lid retraction.-Enophthalmos of C/L eye-Paralysis of extrinsic muscles.

Algorithm for approach to a case of proptosis:

History

Ocular & systemic examination

Specific examination of proptosis

Provisional diagnosis

Imaging

Revision of provisional diagnosis( if required)

Investigations

Confirmation by histopathological examination

Management plan( according to final diagnosis)

Monitoring course of disease

A) HISTORY:

A complete history should be recorded.

Evaluation of the patient with exophthalmos begins with a thorough ophthalmic and medical history.

When concomitant sinus disease or an intranasal source is suspected, a speculum or endoscopic intranasal examination is warranted

Time course of disease: acute( hours-days), subacute(weeks), chronic(months/years)

ACUTE: -traumatic: e.g orbital hematoma -infective: e.g orbital cellulitis

SUBACUTE: -inflammatory: e.g orbital inflammatory diseases, thyroid

orbitopathy. -neoplastic.

CHRONIC: -neoplastic, benign/malignant -inflammatory.

Progression: The proptosis my be progressive,static or waxing-waning.

Rare cases of intermittent proptosis are caused by dumb-bell dermoids,with components in the orbit & the temporal fossa.

Medical & systemic history: pt asked for h/o malignancy,weight loss,smoking.

Biological effects of disease: pain, swelling around the eye,diminished vision,watering, diplopia.

B) OCULAR EXAMINATION: Visual acuity: diminution d/t optic nerve compression,

corneal exposure.

Refraction: acquired hyperopia d/t mass indenting the posterior pole of globe, high myopia causing pseudoproptosis.

IOP: thyroid orbitopathy( d/t restriction of movt.), aretriovenous fistula (d/t elevated venous pressure)

Conjunctiva: chemosis (in severe inflammation), salmon colored patch (in lymphoma), dilated episcleral vessels (carotid cavernous fistula)

Eyelids: lid retraction,lid lag in thyroid orbitopathy, S-shaped lid thickening (neurofibromatosis),lagophthalmos

Cornea: exposure keratopathy.

Iris: lisch nodules. (neurofibromatosis).

Pupil: RAPD

Ocular motility limitations: direct muscle involvement by disease, mechanical limitation,compression of nerves, cavernous sinus thrombosis.

Fundus examination: optic disc edema, disc pallor, choroidal/ ILM folds.

MEASUREMENTS:

Asymmetry > 2mm or more b/w the eyes.

OR

Protrusion greater than-13-15mm in east asians-21mm in caucasian adults.-23mm in adult african-americans

Clinical methods for measurement of proptosis:

A) PLASTIC RULER: can measure proptosis from the lateral orbital rim to the corneal apex,holding the ruler parallel to ground.

B)LUEDDE’S EXOPHTHALMOMETER: has several advantages

-notch confirms to lateral orbital rim. -the scale starts from tip of instrument,where the notch

meets the lateral orbital rim.

-markings on both sides help to avoid parallax error. -luedde’s exophthalmometer is better than hertel’s if there is

facial asymmetry.

C) HERTEL’S EXOPHTHALMOMETER: m/c used. -it may use prisms or mirrors set at 45 degree angles. -it is best for serial follow up of patients.

D) NAUGLE’S EXOPHTHALMOMTER:

-In case of acquired or congential asymmetry of the lateral orbital rims a Hertel exophthalmometer is misleading

-This is an inferior & superior rim based instrument.

-may be used when the lateral orbital rim is not intact.

SOURCES OF ERROR IN EXOPHTHALMOMETRY:

A)failure to have pt look straight.

B)failure to have cross bar parallel to floor.

C)parallax error.

MEASURING PROPTOSIS ON A CT SCAN

HILAL AND TROKEL METHOD:

-In a mid axial CT scan image,a baseline between the tips of lateral orbital rims is drawn.

-a perpendicular from each corneal apex to this line is dropped & measured to scale.

if each line > 21mm or indicates

abnormality. if asymmetry >2mm b/w two

Quick clinical assessment of proptosis:

Worm’s eye view: looking up at pt from below,while pt tilts his head back.

Measurement of dystopia:

-In an eccentric or non axial proptosis, the horizontal & vertical dystopia of globe is to be measured.

-Horizontal dystopia :is measured by the distance from the midline of bridge of nose to the nasal limbus, compared bilaterally.

-Vertical dystopia :is measured by the superior or inferior deviation of the central corneal reflex of the proptotic eye from a horizontal line passing through the centre of normal eye.

CLINICAL ASSESSMENT OF THE MASS:

Inspection of face: may show characteristic features of cranio-synostosis, temporal fossa fullness in sphenoid ridge meningioma.

Palpation: The orbital mass may be palpable.

- mass is evaluated for the extent,border,size,consistency,tenderness,skin over the lesion & whether a finger can be insinuated b/w mass & bony orbital rim.

-most mass lesions which are large enough to extend across the midline of orbit are malignant.

-resistance to retro-displacement of the globe may indicate a tumor or thyroid orbitopathy.

LATERALITY ON INSPECTION: UNILATERAL PROPTOSIS: dermoid cysts,orbital teratoma,congenital cystic eyeball, Orbital hemorrhage,traumatic aneurysm, Cellulitis/abscess, cavernous sinus thrombosis TED,pseudotumour Varices,tumors,cysts.

BILATERAL PROPTOSIS: craniofacial synostosis,osteitis deformans,rickets TED,mickulicz syndrome Histiocytosis,amyloidosis,wegener’s granulomatosis, Tumors.

PULSATION:

-best detected on lateral view/ while using applanation tonometer.

-e.g arterio-venous fistula (high flow carotid-cavernous fistula), Aneurysms.

(dilated episcleral vessels in arterio-venous fistula) OR Due to transmitted pulsation through a defect in the bony orbital

wall.

e.g : Sphenoid wing dysplasia ( in neurobibromatosis), Meningo encephalocele, Herniation of frontal lobe of brain into orbit following

trauma.

AUSCULTATION: carotid-cavercous fistula bruit heard best by the bell of

stethoscope

- INVESTIGATIONS:

Imaging studies Thyroid function tests complete blood count

-CT scan[axial/coronal/sagittal](most useful) T3,T4,TSH blood culture

-MRI nasal culture

-ocular ultrasound(USG) casoni’s test, montoux test, -X ray urine analysis(bence jones

protein) c-ANCA,ACE,ANA-Carotid angiography biopsy/FNAC,

-orbital venography stool examination

-Visual fields/ hess chart

PROPTOSIS:

A) AXIAL B) ECCENTRIC

Axial proptosis: lesions of intraconal space arising from optic nerve or central space. E.g-optic nerve glioma

-optic nerve sheath meningioma

-cavernous hemangioma

-schwannoma

-neurofibroma

-orbital varix,hydatid cyst etc.

CAUSES OF ABAXIAL DISPLACEMENT OF GLOBE:

Downward displacement:

-fibrous dysplasia

-frontal mucocele

-subperiosteal hematoma

-lymphoma

-neuroblastoma

-neurofibroma

-schwannoma

-thyroid orbitopathy

Upward displacement of globe:

-Lacrimal sac tumour -lymphoma -maxillary sinus tumour -metastatic tumors

Lateral displacement of globe:

-Lacrimal sac tumors. -ethmoid mucocele metastatic tumors -lethal midline granuloma -nasopharyngeal tumors -rhabdomyosarcoma

Medial displacmenet of globe:

-Lacrimal gland tumors -sphenoid wing meningioma

Classification of causes of proptosis:

Infectious: Orbital cellulitis,Mucormycosis,subperiosteal abscess,gumma,Concurrent sinus disease

Inflammatory :Orbital inflammatory syndrome (orbital pseudotumor, benign orbital inflammation,IOIS),Thyroid orbitopathy,sarcoidosis,histiocytosis.

 

Vasculitis: Wegener granulomatosis,Churg-Strauss syndrome ,Poly arteritis Nodosa

Orbital vascular disease: Orbital varix (venous malformation) Orbital arteriovenous malformation (carotid-cavernous sinus fistula, arteriovenous malformation)

Trauma: Traumatic or iatrogenic orbital hemorrhage, Orbital blow out fractures, Facial fractures,retained foreign body

Pseudoproptosis (pseudoexophthalmos): Buphthalmos ,Contralateral enophthalmos ,Ipsilateral lid retraction ,Axial myopia ,Contralateral blepharoptosis.

Neoplastic : Leukemia,optic nerve Glioma,optic nerve sheath meningioma,leukaemia,retinoblastoma,neurofibroma,metastasis,rhabdomyosarcoma,lymphangioma, Lacrimal Lymphoma ,pleomorphic lacrimal gland adenoma.

EWING’S SARCOMA

MASSIVE HEAD ACTINOMYCETOMA WITH SEVERE BILATERAL PROPTOSIS

OPTIC NERVE SHEATH MENINGIOMA

OPTIC NERVE GLIOMA

LYMPHANGIOMA

RHABDOMYOSARCOMA

PFEIFFER SYNDROME:

CAVERNOUS HEMANGIOMA

CAROTID-CAVERNOUS FISTULA (ARTERIO-VENOUS FISTULA)

CAPILLARY HEMANGIOMA

KEY POINTS

The most common cause of bilateral proptosis is Graves disease.

Acute unilateral proptosis suggests infection or vascular disorder (eg, hemorrhage, fistula, cavernous sinus thrombosis).

Chronic unilateral proptosis suggests tumor.

Do CT or MRI and thyroid function testing when Graves disease is suspected.

Apply lubrication to exposed cornea.

THANK YOU..