Disease of the orbit Topic 21
Orbital diseases are ones that are concerned with structures in the orbits and how disorders affecting them, will affect the eye itself
They will be divided in the following division
- 1. Proptosis → forward displacement of the eyeball
- 2. Developmental → heredity abnormality of skull &facial bones
- 3. Orbital inflammations/infections
- 4. Graves ophthalmopathy
- 5. Orbital tumours & optic nerve involvement
a) Proptosis
When eyeball is pushed out beyond orbital margins ; exophthalmos (reserved for thyroid)
-Classification and aetiology
a) Unilateral Proptosis
- Congenital (teratoma,cystic eyeball), Traumatic lesion (orbital haem, intraorbital foreign body, traumatic aneurysm ) , inflammatory lesions (orbital cellulitis, abscess, thrombophlebitis, cavernous sinus thrombosis & chronic inflammatory)
- Vascular lesions , Cysts of orbit (haematic &hydatid cyst) , all types of tumours
b) Bilateral Proptosis
- Developmental anomalies of skull ( craniofacial dysostosis→ fusion to early but eye carries on growing thus protrudes )
- Osteopathies (rickets , acromegaly), Endocrinal exophthalmos, tumours (lymphosarcoma ,neuroblastoma), systemic diseases
c) Acute Proptosis
- Medial orbital wall fracture, orbital haemorrhage
d) Pulsating Proptosis → pulsating vascular lesions (caroticocavernous fistula)
Clinical course
- history with onset, signs and symptoms
- differentiate from pseudoptoptosis , check if uni or bilateral
- Palpation to check for regional lymph nodes, swelling &tumours
- Ocular motility → restricted in thyroid
- Exophthalometry → normal 10-21 mm and symmetrical
- Difference of 2mm is significant
- Systemic examination: check for thyroid function ,rule out hydatid cyst, stool examination to check for cysts and ova ,urine analysis to rule out multiple myeloma
b) Developmental anomalies of the orbit
- Abnormalities of skull and facial bones usually autosomal dominant
- The ocular features include Proptosis, strabismus , papilloedema and optic atrophy
- Craniosynostosis → premature closure of one or more cranial sutures
- Craniofacial dysostosis (crouton’s syndrome)→ all sutures closed early
- Hypertelorism → widely separated eyeballs resulting from widely separated &broad nasal bridge
c) Orbital inflammations
A. Acute
I. Pre-septal (periorbital) cellulitis
- Infection of subcutaneous tissue anterior to the orbital septum (not orbital disease but the valveless facial veins allow prespetal cellulitis to spread causing orbital cellulitis )
- Staphylococcus aurous/pyogenic→ via following skin laceration via blood
- Clinical: oedema of eyelids and periorbital skin but no orbital involvement
II. Orbital cellulitis/abscess → soft tissue involvement behind orbital septum
- it may progress to subperiosteal abscess or orbital abscess (behind eye, puss accumulation)
- aetiology→ penetrating injury or operation, extension from neighbouring structures (Para nasal sinuses, teeth, face, lids, intracranial & intraaorbital structures) (most common)
- Staph. Aureus(from skin), strept, pneumonia (sinus)