ORBIT المحجر

Bony Orbit Seven bones, arranged to form a pyramidal shaped space (orbit) which contains eye ball, EOM, Optic N., vessels, nerves and other connective tissue components. It has Base (anterior) & Apex (posterior) Medial 1. Maxillary b. +  ant. Lac. Crest Wall Frontal b. lacrimal 2. Lacrimal  post. Lac. Crest fossa 3. Ethmoidal (lamina paperacya) Ant. back * very thin, * blow out fracture, * ethmoidal sinus orbital cellulitis 4. Body of sphenoid

Floor 1. Maxillary bone (medially) 2. Zygomatic bone (laterally) 3. Palatine (posteriorly) • Infraorbital n. runs in groove, canal, foramen  lower lid • Maxillary sinus below * Blow out Fracture Lateral 1. Frontal bone (above) Wall 2. Zygomatic bone (below) 3. Greater wing of sphenoid (posteriorly) It separates the orbit from: 1. Temporal fossa (anterior) 2. Middle cranial fossa & temporal lobe (posterior) * Thickest wall

Roof Frontal bone, Lesser wing of sphenoid 1. Frontal sinus (within supraorbital rim) 2. Anterior cranial fossa & frontal lobe - Trochlea / Supra orbital notch / Fossa of lacrimal gland.

The bony orbit Walls

Superior Orbital Fissure Between roof & lateral wall Transmits structures passing between middle cranial fossa and the orbit 1. Oculomotor n. 2. Trochlear n. 3. Ophthalmic n. branches 4. Abducens nerve 5. Superior & inferior ophthalmic vein Inferior Orbital Fissure Between floor & lateral wall Transmits branches of maxillary nerve (infraorbital nerve, zygomatic nerve) from pterygopalatine fossa.

The Bony Orbit

Peri orbita .. At the orbital rim (margin) Optic Canal Transmits: 1. Optic nerve (+ CRA) 2. Ophthalmic artery Between orbit & middle cranial fossa The periosteum of the orbital wall is called: Peri orbita .. At the orbital rim (margin) It extends downward (up) within the lids until if fuse with the tarsal plate and called: Orbital Septum the orbital septum limits the orbit anteriorly..

Optic canal

Apex: Posterior part of whore the 4 walls converge.. Near the optic canal and posterior part of superior and inferior orbital fissures The 4 recti arise from a common tendinous ring at the apex & run forward along corresponding walls in the form of Cone around the optic nerve..

Orbital Apex & Tendinous Ring

Orbital Investigations: Orbital Symptoms 1. Proptosis. 2. Pain. 3. Ophthalmoplagia (EOM motility disorder). 4. Periorbtal changes (swelling, redness, chemosis). Orbital Investigations: 1. Orbital examination 2. Exophthalmometry 3. U/S 4. C.T. 5. MRI

Exophthalmometry

Proptosis (Exophthalmos): Forward protrusion of the eye ball.. (normally the corneal apex does not protrude in front of the orbital margins..) Differentiate it from pseudoexophthalmos E.g.: • lid retraction • contralateral enophthalmos • large eye ball  buphthalmos

Exophthalmos

Aetiology of the Proptosis: Examination: • Inspection • Ruler • Hertel exophthalmometer Aetiology of the Proptosis: 1. Endocrine  thyrotoxicosis 2. Inflammatory  orbital cellulitis 3. Tumors  *cyst *benign or malig. 1ry tumor * metastasis 4. Traumatic  retrobulbar hemorrhage 5. Vascular  * AV malformation *orbital varix *caroticocavernus fistula

Analysis of Proptosis: 1.  Axial  intraconal  Non axial (displaced)  extraconal  … 2. Bilateral proptosis  thyrotoxicosis 3. Unilateral proptosis  1.Thyrotoxicosis 2.Orbital Cellulitis 3.Tumours… etc 4. Rapid onset proptosis  Trauma  emphysema  hemorrhage 5. Intermittent exo. (positional)  orbital varicosity Commonest cause of exoph.  Thyrotoxicosis Commonest cause of exoph. In child orbital cellulitis

Unilateral Proptosis

Orbital Cellulitis Suppurative inflammation of the orbital soft tissue behind the orbital septum. It is either Extension from neighboring str. (sinuses) Trauma Comm. Micro.: *Strept. * Staph. * Pneumococci

Orbital Cellulitis

Orbital Cellulitis

Clinical features: 1. Swelling & redness of the lids. 2. Conjunctival chemosis 3. Exophthalmos 4. Pain 5. Diplopia 6. Constitutional symptoms 7. Vision may be impaired (optic neuritis)

Complications: 1. Orbital abscess 2. Panophthalmitis 3. Meningitis 4. Brain abscess 5. Cavernous sinus thrombosis

Treatment: ( Admission) 1. Systemic antibiotics child  Ampicillin + Cloxacillin adult  3rd generation cephalosporin + Metronidazole 2. Monitoring of optic nerve function (VA, pupils) 3. Investigation *WBC count *CT of orbit, brain & sinuses *LP if suspect meningitis 4. Surgical drainage, if: a. no response to antibiotics b. orbital abscess N.B. Preseptal cellulitis

Rhabdomyosarcoma The most common primary malignant orbital tumor in children Highly malignant, in its early stages may be mistaken as orbital cellulitis 7 years Present as rapidly progressive proptosis, other signs include: 1. palpable mass 2. ptosis 3. swelling & injection of overlying skin (but not hot)

Rhabdomyosarcoma

Investigations: Treatment: 1. Biopsy for diagnosis 2. Systemic assessment for metastasis by CXR, LFT, BMA, LP, skeletal survey.. Treatment: Local radiotherapy + chemotherapy IF no response  Exentration

Blow out fracture Floor  medial wall Trauma by an object whose size is larger than the diameter of the orbital inlet.  ↑ intraorbital pressure  transmitted force These will affect weak areas..

Signs & Symptoms: 1. Surgical emphysema, edema, echymosis 2. Diplopia (tethering of orbital contents, e.g.: inferior rectus) with restricted up movement. 3. enophthalmos, orbital fat necrosis 4. Anesthesia along the infra orbital n. distribution 5. Hypotropia 6. Intraocular damage (e.g.: hyphema)

Investigations: Treatment: CT of the orbit & maxillary sinus 1. Systemic antibiotics 2. Not blow the nose 3. Surgery  timing  indications  procedure

Blow out Fracture

Blow out Fracture

Blow out Fracture