[WinFlash] Q1=ORBIT^ ^ ^ANATOMY A1=1 Pyramidal, volume about 30 ml^2 Height about 34 mm, width about 39 mm, depth about 45 mm^3 Constricted anteriorly; maximum diameter 1 cm behind rim (equator of globe in this position)^4 Anterior opening roughly square^5 Medial walls parallel; lateral walls perpendicular to each other^6 Medial and lateral walls intersect at 45°^7 Orbital axis 22.5° to the sagittal plane^ Q2=Orbital Roof: A2=(a) thin: made up of frontal bone, lesser wing of sphenoid^(b) relations:^(i) superiorly--frontal sinus, anterior cranial fossa^(ii) anterolaterally--lacrimal gland depression^(iii) anteromedially--trochlear depression (4 mm behind rim); trochlear spine in 10% of skulls^(iv) anteriorly--supraorbital notch (1/3 from medial end)^ Q3=Medial Wall A3=Medial:^(a) very thin (0.2-0.4 mm); made up of frontal, maxillary, lacrimal, ethmoid, and body of sphenoid bones^(b) relations:^(i) medially--nasal sinuses and anterior ethmoidal artery and nerve^(ii) anteriorly--lacrimal fossa (anterior and posterior crests) (iii) superiorly--frontoethmoid suture (obliterated with age) (iv) posteriorly--optic canal Q4=Orbital Floor: A4= Floor:^(a) thin (0.5-1.00 mm); made up of maxillary, zygomatic, and palatine bones^(b) relations:^(i) inferiorly--maxillary sinus; infraorbital foramen 4 mm below, 1-3 mm from medial end^(ii) medially--fossa of inferior oblique insertion (inferolateral to nasolacrimal duct) Q5=Lateral Wall A5=Lateral:^(a) strongest, no relations to sinuses; made up of zygomatic bone and greater wing of sphenoid bone^(b) relations:^(i) anterolaterally--temporal fossa^(ii) posterolaterally--middle cranial fossa^(iii) superiorly--frontozygomatic suture (common site for^dermoids)^(iv) laterally--zygomatic foramina (zygomaticofacial and zygomaticotemporal nerves)^(c) lateral orbital Whitnail's tubercle, 11 mm below frontozygomatic suture; insertion of:^(i) lateral palpebral ligament ^(ii) lateral rectus cheek ligament ^(iii) levator aponeurosis^(iv) suspensory ligament of globe Q6=Orbital Contents A6=Contents^1 Globe^2 Orbital fat (intraconal and extraconal)^3 External ocular muscles^4 Nerves (II, III, IV, Va, VI, and sympathetic nerves)^5 Vessels (branches of ophthalmic artery, and superior and inferior ophthalmic veins)^6 Lacrimal gland Q7=Superior orbital fissure A7=1 About 2 cm long ^2 Relations:^(a) superiorly: lesser wing of sphenoid^(b) inferiorly: greater wing of sphenoid^3 Connects orbit with middle cranial fossa^4 Transmits III, IV, Va nerves, superior ophthalmic vein, and recurrent meningeal artery^5 Laterally occluded by dura and periosteum Q8=Inferior orbital fissure A8=1 About 2 cm long ^2 Relations:^(a) superiorly: greater wing of sphenoid bones^(b) inferiorly: palatifie/maxillary and zygomatic bones^3 Connects orbit with infratemporal and pterygopalatine fossae^4 Separated from superior orbital fissure by neck of sphenoid^5 Traversed by maxillary nerve^6 Transmits zygomatic nerve, sympathetic fibres, and venous anasto-mosis^7 Largely occluded by periosteum Q9=Branches of the ophthalmic artery^ ^ A9=1 Central retinal artery^2 Posterior ciliary arteries:^(a) about 15 short arteries ^(b) about 2 long arteries^3 Lacrimal artery^4 Recurrent meningeal branches^5 Muscular branches: anterior ciliary arteries^6 Supraorbital artery^7 Ethmoidal arteries: (a) posterior (b) anterior^8 Medial palpebral arteries: (a) superior (b) inferior^9 Terminal branches: (a) supratrochlear artery (b) dorsal nasal arteries Q10=Draw Apex Diagram A10=C:\Program Files\WINFLASH\Images\apex of orbit 2.jpg%Figure 2.1 Superior orbital fissure (schematic diagram)^Key:^Above annulus of Zinn: SOV = superior orbital vein; L = lacrimal nerve; F= frontal nerve; IV=fourth nerve^Through annulus of Zinn: IIIs=third nerve (superior division); NC=nasociliary nerve; IIIi=third nerve (inferior division); VI=sixth nerve^Below annulus ofZinn: IOV=inferior orbital vein^Muscles: LPS = ievator palpebrae superioris; SO = superior oblique; SR = superior rectus; MR = medial rectus; IR = inferior rectus; LR = lateral rectus Q11=Optic foramen^ A11=1 Transmits optic nerve and ophthalmic artery through sphenoid bone^2 Downward and outward at 36° to the midline^3 Lateral wall 5-7 mm^4 Roof 10-12 mm^5 Dura adherent to walls^6 Ophthalmic artery inferior then lateral to optic nerve^7 Medially: sphenoid sinus and posterior ethmoid air cells Q12=Periosteum^ A12=1 Lines orbit^2 Adherent at sutures and foramina^3 Binds down superior oblique tendon^4 Thickened at orbital rim at insertion of orbital septum^5 Divides to enclose lacrimal sac^6 Continuous over superior orbital fissure and inferior orbital fissure Q13=EMBRYOLOGY^ ^ A13=1 Ethmoid, sphenoid: from cartilage^2 Frontal, lacrimal: from membrane^3 Maxilla, palatine, zygoma: from first branchial arch Q14=ORBITAL SYMPTOMS^ ^ A14=1 Globe position^2 Lid appearance^3 Diplopia^3 Visual impairment^4 Pain Q15=ORBITAL SIGNS AND EXAMINATION^ ^ A15=1 Proptosis: measure with exophthalmometer from lateral orbital rim to corneal apex; normal <<20 mm; >2 mm difference between eyes significant; types:^(a) axial: intraconal (dysthyroid eye disease most common) (b) non-axial: extraconal (95% tumours) (c) dynamic properties:^(i) increase with Valsalva manoeuvre^(ii) pulsation^(iii) vascular lesion or defect in bony wall^2 Vision: may be impaired as a result of:^(a) optic nerve compression caused by raised intraorbital pressure (tight septurn) or direct pressure on, or infiltration of, the optic nerve; reduced colour vision an early sign^(b) raised intraocular pressure ^(c) exposure keratopathy ^(d) choroidal folds^(e) pseudohypermetropia^(f) field defects^3 Strabismus:^(a) ocular movements (-+globe displacement, restrictive or paralytic palsy)^(b) forced duction test (muscle tethering or contraction)^4 Palpation:^(a) lumps and local swellings (check lacrimal gland)^(b) tenderness^(c) retropulsion of the globe^5 Reduced sensation in branches of Va and Vb^6 Auscultation: listen for bruit (e.g. caroticocavernous fistula)^7 Slitlamp:^(a) tear film instability with exposure^(b) superior limbic keratoconjunctivitis associated with dysthyroid eye^disease^(c) conjunctival vessels^(i) arterialised (dural shunt)^(ii) tortuous at muscle insertion (dysthyroid eye disease)^(d) raised intraocular pressure particularly on upgaze^8 Ophthalmoscopy: (a) disc pallor (b) disc swelling^(c) opticociliary shunts^(d) choroidal folds^9 General examination Q16=CAUSES OF PSEUDOPROPTOSIS^ ^ A16=1 Ipsilateral:^(a) high myopia^(b) buphthalmos^(c) orbital asymmetry^(d) lid retraction^ ^2 Contralateral:^(a) enophthalmos^(b) ptosis^(c) microphthalmos^ Q17=CAUSES OF PULSATILE PROPTOSIS^ ^ A17=1 Caroticocavernous fistula^2 Large frontal mucocele^3 Meningoencephalocele^4 Arteriovenous malformation^5 Neurofibromatosis in children Q18=RADIOLOGICALVIEWS OFTHE ORBIT^ ^ A18=Superseded by ultrasound scans, computed tomography, and magnetic resonance imaging.^1 Caldwell's view: general view^2 Waters' view: orbital floor^3 Rhese's view: optic foramen^4 Lateral view/axial basal view: sinuses^ Q19=PHLEBOGRAPHY^ ^ A19=1 Not commonly used^2 Performed via frontal or angular vein^3 Outlines superior ophthalmic vein in 3 portions: (a) extraconal (b) intraconal above optic nerve (c) intraconal lateral to optic nerve^4 Apsidal veins connect with inferior ophthalmic vein^5 Inferior ophthalmic vein may not fill^6 Need to compare both sides^ Q20=ULTRASONOGRAPHY^ A20=1 Produced by a piezoelectric crystal; the transducer transmits and receives 1000 times/s; frequency range: 5-20 MHz^2 Propagation through tissues depends on velocity, absorption, and frequency^3 Ultrasound is refracted, reflected, and absorbed by ocular and orbital structures^4 Reflected sound returning along the path of the propagated beam is recorded^5 A-scan: one dimensional; time-amplitude study^6 B-scan: two dimensional; sectional view with a scanning transducer^7 Ultrasonic probe coupled to ocular structures, using, for example, 5% methyl cellulose or by immersion coupling using waterbath^8 Ocular diagnostic applications: (a) posterior vitreous detachment 0a) vitreous haemorrhage (c) retinal detachment^(d) massive preretinal fibrovascular proliferation^(e) intraocular tumours^(f) intraocular foreign bodies^(g) biometry^9 Orbital applications:^(a) high reflectivity:^(i) dysthyroid myopathy (ii) haemangioma (iii) neurofibroma^(b) low reflectivity:^(i) cyst^(ii) mucocele^(iii) varix^(iv) lymphoma Q21=COMPUTED TOMOGRAPHY^ ^ A21=1 Investigation of choice in most orbital disease^2 Pixel size governs definition (volume averaging)^3 Slices either thick (3 mm) or thin (1-5 mm) and either contiguous or stepped^4 Axial slices normally parallel to Reid's baseline (external auditory meatus to inferior orbital rim)^5 Optic canal views best at angle of 30° to baseline^6 Coronal and sagittal views possible; reformatted image quality depends on slice thickness and separation^7 Contrast depends on tissue density; Hounsfield scale grades contrast (-1000 -- air, 0 -- water, + 1000 = dense bone)^8 Intravenous contrast:^(a) enhancement of normal vascular structures:^(i) extraocular muscles (ii) lacrimal gland (iii) arteries and veins (iv) uveoscleral rim (b) essential extraorbital extension, e.g. intracranial (c) helpful with:^(i) venous thrombosis^(ii) cystic masses^(iii) optic nerve tumours^ Q22=MAGNETIC RESONANCE IMAGING^ ^ A22=1 Investigation of choice in most intracranial disease^2 Intensity of signal dependent on hydrogen proton density, andT~ andT2 relaxation times^3 Surface coils increase resolution of orbital pathology^4 Advantages over CT scan:^(a) no radiation^(b) no elaborated patient positioning^(c) less image degradation, e.g. dental fillings^(d) good optic canal, chiasma, and differentiating optic nerve from adjacent masses; also differentiating flowing from clotted blood and inflammatory lesion~^5 Disadvantages compared with CT scan: (a) patient motion artefacts (b) poor spatial resolution (c) no signal from calcification^(d) potential dangers with pacemakers and foreign bodies^(e) higher cost^ Q23=CONGENITAL ABNORMALITIES OF THE ORBIT^ ^ A23=1 Early suture closure:^(a) alt synostoses: may produce hydrocephalus^(b) oxycephaly:^(i) all sutures closed^(ii) tower skull^(iii) proptosis (50%), visual failure, exotropia^(c) brachycephaly: coronal suture closure^(d) Crouzon's disease^(i) brachycephaly and maxillary hypoplasia^(ii) hypertelorism: shallow orbits, proptosis, exotropia, optic atro-^phy, irregular dentition, hooked nose 2 Primary or secondary underdevelopment of the orbit:^(a) mandibulofacial dysostosis:^(i) hypoplasia of mandible and zygoma^(ii) shallow inferior orbital rim^(iii) lower lid abnormalities, anti-Mongoloid slant^(b) hypertelorism:^(i) early ossification of sphenoid wings^(ii) exotropia^(c) hydrocephalus: shallow orbits, optic atrophy^(d) micro-/anophthalmos: underdeveloped orbits^(e) buphthalmos: large orbit Q24=FACIAL FRACTURES OF THE ORBIT^ ^ A24=1 Le Fort III: separation of face from cranium^2 Le Fort II: separation of central block of face from skull^3 Malar fractures: fractures involving zygomaticofrontal process, zygo-matic arch, and maxilla; often displaced and requires open reduction^ Q25=BLOW OUT FRACTURES OFTHE ORBIT^ ^ A25=1 Orbital floor/medial wall fractures resulting from blunt trauma; trans-mitted forces result in deformation and fracture^2 Pure; do not involve rim^3 Complicated; involve rim^4 Pure floor fracture may be linear or punched out with or without prolapse or incarceration of orbital contents^5 Clinical features:^(a) suggestive history^(b) enophthalmos, although may have proptosis (c) hyper- or hypoaesthesia of infraorbital area (d) surgical emphysema^(e) limited ocular movements; may be due to:^(i) oedema or haemorrhage within extraocular muscle^(ii) nerve trauma^(iii) entrapment of tissues^(iv) hypoglobus or enophthalmos^(f) rise in intraocular pressure on upgaze^(g) nasal bleeding (unilateral)^6 Investigations:^(a) assess ocular position (exo4enophthalmos, hypoglobus) (b) field of binocular single vision, Hess (Lees) screen (c) CT scan (coronal sections):^(i) fluid level in sinuses^(ii) hanging drop sign^(iii) look for fracture of orbital rim and medial wall^(d) forced duction test^7 Management:^(a) conservative^(b) surgery: repair by 14 days after injury; extraocular muscle surgery^should be delayed; indications for surgery include:^(i) fracture involving the rim^(ii) linear fracture and tissue entrapment (iii) enophthalmos >3 mm or hypoglobus (iv) diplopia in primary position^(v) small field of binocular single vision^(vi) positive forced duction test^(c) principles:^(i) repair defect with bone or non-autogenous material^(ii) strabismus surgery may be required--inferior rectus recession^(adjustable), or reverse Knapp procedure Q26=OTHER ORBITAL FRACTURES^ A26=1 Orbital roof fractures: associated with sharp objects; danger of intracranial penetration and retained foreign bodies; blunt trauma to frontal area may result in linear fractures; these may involve the optic canal^2 Trochlear disinsertion:^(a) sharp trauma^(b) iatrogenic, e.g. while approaching ethmoidal artery in treatment of^epistaxis^ Q27=CAUSES OF ORBITAL HAEMORRHAGE^ ^ A27=1 May be subperiosteal or intraorbital^2 Causes:^(a) trauma: high risk of visual loss^(b) spontaneous: varices, lymphangioma (c) iatrogenic: retrobulbar injection^ Q28=CAROTICOCAVERNOUS FISTULA^ ^ A28=1 Causes:^(a) direct (communication between internal carotid artery and cavern-ous sinus)--usually trauma to sclerotic aneurysm (75%)^ ^ ^(b) dural (communication between dural branches and cavernous^sinus)--usually spontaneous (25%)^2 Clinical features:^(a) high flow:^(i) pulsating exophthalmos^(ii) bruit^(iii) diplopia (limited eye movements)^(iv) pain^(v) conjunctival congestion and chemosis^(vi) increased intraocular pressure^(vii) dilated conjunctival vessels, forehead veins, and choroidal^vessels (arterialisation)^(viii) visual impairment^(ix) optic nerve ischaemia^(x) intraocular hypoxia (rubeosis)^(b) low flow: as above but less severe^3 Prognosis: 5% spontaneous cure, 50% vision lost^4 Management:^(a) conservative^(b) neuroradiological balloon catheter embolisation^(c) internal carotid ligation^ Q29= Preseptal cellulitis:^ A29=(a) lid oedema, erythema, and tenderness^(b) orbital contents undisturbed^ Q30=Orbital cellulitis:^ A30=(a) features as above with reduced motility, proptosis, fever, and pain^(b) aetiology:^(i) spread from sinuses, dental abscess, or skin infec6on^(ii) direct infection following trauma or surgery^(iii) systemic infection^(c) causes:^(i) Staphylococcus aureus and Streptococcus spp. most common^(ii) Haemophilus influenzae in children <<3 years of age^(d) complica6ons:^(i) central retinal artery or vein occlusion^(ii) optic nerve inflammation^(iii) cavernous sinus thrombosis^(iv) brain abscess^(e) management:^(i) CT scan^(i0 blood culture^(iii) culture of any infectious site, e.g. conjunctiva, nasopharynx^(iv) high dose intravenous antibiotics^(v) nasal decongestants or sinus washout^(vi) surgical drainage of abscess Q31=3 Orbital abscess:^ A31=(a) may be intraorbital or subperiosteal^(b) associated with orbital cellulitis Q32=4 Cavernous sinus thrombosis:^ A32=(a) associated with orbital cellulitis^(b) marked limitation of motility, visual loss, palsies of III, IV, V, VI ^(c) bilateral extension; oedema over mastoid (emissary vein) ^(d) fever, prostration^(e) treatment: antibiotics, anticoagulants^(f) prognosis poor Q33=CHRONIC ORBITAL INFECTIONS^ ^ A33=1 Causes:^(a) tuberculosis^(b) syphilis^(c) fungal (Aspergillus and Mucor spp.)^ ^2 Signs:^(a) irreducible proptosis^(b) orbital apex syndrome (ptosis, visual loss, internal and external ophthalmoplegia) Q34=ORBITAL INFESTATIONS^ ^ ^ A34=1 Cysticercosis (larvae ofTaenia solium)^2 Trichinosis (Trichinella spiralis)^3 Hydatid disease (Echinococcus granulosus) Q35=DYSTHYROID EYE DISEASE^ ^1 Associations: A35= usua%1 Associations:^(a) hyper-/hypothyroidism although patient may be clinically euthyroid ^(b) thyroid acropachy, pretibial myxoedema (Graves' disease) ^(c) pernicious anaemia ^(d) myasthenia gravis ^(e) Addison's disease^(f) HLA association varies with different populations Q36=DYSTHYROID EYE DISEASE^ ^2 Aetiological theories:^ A36=(a) uncertainty over exact aetiology^(b) T cells active against common antigen (orbit and thyroid)^(c) antibodies may activate T and B cells (thyroglobulin, thyroid^microsomal, TSH receptor)^(d) T and B cells may activate orbital fibroblasts resulting in self perpetuating inflammation^(e) fibroblasts produce glycosaminoglycans that hydrate; fibrosis and^tethering may result Q37=DYSTHYROID EYE DISEASE^ ^3 Epidemiology A37= = 4:1; ^average age of onset 50 years; ^worse disease in smokers Q38=DYSTHYROID EYE DISEASE^ ^4 Werner classification = NO SPECS:^ A38=No symptoms or signs^ ^Only signs, e.g. lid retraction, lid lag, superior limbic keratoconjunctivitis^ ^Soft tissue swelling, e.g. lid oedema^ ^Proptosis:^(a) 21 mm taken as the upper limit of normal^(b) unilateral or bilateral^(c) septal tightness may play a role in preventing proptosis ^Extraocular muscle involvement; most commonly inferior rectus and medial rectus; infiltrative and restrictive following fibrosis ^ ^Corneal ulceration ^ ^Sight loss:^(a) corneal ulceration^(b) optic neuropathy^(c) raised intraocular pressure^(apart from the first 2 grades all the others are subdivided into absent, minimal, moderate, and severe) Q39=DYSTHYROID EYE DISEASE^ ^5 Histology:^ A39=(a) external ocular muscles: up to ×8 increased size as a result of^lymphocytic infiltrate; later necrosis and fibrosis^(b) orbital fat: proliferation and mucopolysaccharide deposits^ Q40=DYSTHYROID EYE DISEASE^ ^6 Investigations:^ A40=(a) thyroid function: T3, T4, TSH, and TRH test^(b) autoantibodies: including anti-thyroid microsomal, anti-thyroid^stimulating globulin^(c) B-scan ultrasound^(d) CT scan: enlarged muscles and exclude other orbital pathology; tendon insertions are always spared^(e) biopsy: rarely required as diagnosis usually evident^ ^ Q41=DYSTHYROID EYE DISEASE^ ^7 Management:^ A41=(a) assess thyroid status; treatment of thyroid disorder may worsen^ocular condition, e.g. radioiodine treatment^(b) corneal protection:^(i) lubricants^(ii) moist chamber^(iii) tarsorrhaphy (surgically or with botulinum toxin)^(c) intraocular pressure: reduce if raised^(d) systemic corticosteroids: for acute disease with optic nerve com-pression; immunosuppressive agents may be required (e) radiotherapy (2000 cGy)^(f) orbital decompression (up to 3 wall)^(g) external ocular muscle surgery and/or injection of botulinum toxin^into muscles^(h) lid retractor surgery-+ blepharoplasty Q42=PSEUDOTUMOUR^ ^ A42=1 Definition: non-specific, non-neoplastic, polyclonal inflammation affecting any or all soft tissue components^2 Clinical features:^(a) middle aged women most commonly affected^(b) clinical picture depends on predominant site of involvement:^(i) anterior (ii) lacrimal (iii) posterior (iv) diffuse (v) myositis (vi) orbital apex syndrome (vii) Tolosa-Hunt syndrome (viii) bilateral--30% are children^3 Histology: polyclonal cellular infiltration with variable amount of fibrosis and no evidence of vasculitis^4 Management:^(a) make histological diagnosis to exclude:^(i) lymphoma^(ii) polyarteritis nodosa, Wegener's granulomatosis, sarcoidosis, and Waldenstrom's macroglobulinaemia^(b) systemic corticosteroids^(c) radiotherapy Q43=ORBITAL TUMOURS^ A43=1 Primary: 70%^2 Direct spread: 23%^3 Distant spread: 4%^4 Systemic disease: 3%^ Q44=VASCULAR TUMOURS^ ^ A44=Most common primary benign tumours.^ ^1 Capillary haemangioma:^(a) present in infancy^(b) may be superficial (strawberry naevus), deep, or mixed^(c) dynamic proptosis^(d) initially increase in size; regress by 5 years^(e) may cause astigmatism, amblyopia, or disfigurement^(f) treatment by local injection of steroid or surgery^ ^2 Cavernous haemangioma:^(a) adults^(b) slowly progressive, unilateral proptosis^(c) intraconal with dilated cavernous; blood filled spaces within a^capsule^(d) treatment: surgical, excision^ ^3 Lymphangioma:^(a) rare; of unknown origin^(b) fluid filled cystic spaces; may involve conjunctiva, eyelids, orbit, and^oropharynx^(c) slow growing infiltrative lesions; may increase in size with upper respiratory tract infections; may haemorrhage (chocolate cysts) and present acutely^(d) treatment: large surgical debulking or drainage of chocolate cyst^ ^4 Varix:^(a) most common vascular abnormality^(b) non-pulsatile proptosis, which may have increase on a Valsalva^manoeuvre^(c) phlebolith on CT scan^ ^5 Haemangiopericytoma: very rare Q45=NEURAL TUMOURS^ ^ A45=1 Optic nerve glioma (juvenile pilocytic astrocytoma): (a) 4-8 years of age; 55% have neurofibromatosis (b) slowly progressive proptosis^(c) fusiform optic nerve enlargement (intradural growth)^(d) benign indolent hamartoma with astrocytic replacement of optic^nerve^(e) management usually conservative; surgical resection if tumour^extends into optic canal; radiotherapy useful if tumour intracranial 2 Meningioma:^(a) women > men, 40-50 years of age^(b) primary or from intracranial spread, e.g. sphenoid ridge^(c) slow growing, locally invasive^(d) early visual loss before onset of proptosis^(e) fundal signs:^(i) optic disc swelling^(ii) optic atrophy^(iii) opticociliary shunts^(f) histology: arises in arachnoidal tissue; syncytial arrangement of cells^with psammoma bodies^(g) Management is conservative or radical excision^3 Neurofibroma:^(a) associated with neurofibromatosis^(b) proliferation of Schwann cells, endoneural fibroblasts, and axons^within nerve sheath^(c) management: conservative or surgical debulking^ Q46=LYMPHOMA^ ^ A46=1 Age group: patients usually over 60 years of age^ ^2 Types: range from benign lymphoid hyperplasia (polyclonal) to lym-phoma (monoclonal)^ ^3 Usually isolated in the orbit but exclude systemic disease, e.g.: (a) systemic lymphoma (b) leukaemic deposits (c) plasmacytoma (d) myeloma^ ^4 Management:^(a) biopsy for histological classification^(b) staging:^(i) general examination^(ii) blood count and peripheral blood cell markers ^(iii) chest radiograph, whole body CT scan ^(iv) bone marrow aspiration ^(v) lymphangiography^(c) radiotherapy (10-30 Gy) usually adequate for isolated disease;^chemotherapy if systemic^ ^5 Prognosis: excellent for local disease Q47=MESENCHYMAL TUMOURS^ ^ A47=1 Benign: rare; of any orbital component; occasional sarcomatous change^2 Sarcoma associated with Paget's disease (! %) and orbital radiotherapy for retinoblastoma^3 Rhabdomyosarcoma:^(a) clinical features^(i) most common primary malignant tumour of children; arises in embryonal mesenchymal rests with potential to differentiate into striated muscle (ii) average age 7 years^(iii) rapid growth of mass in superonasal quadrant^(iv) non-axial proptosis^(v) may have inflammatory appearance^0a) types:^(i) embryonal--most common in orbit^(ii) alveolar^(iii) pleomorphic--rare in orbit^(iv) botyroid^(v) differentiated^(c) management:^(i) biopsy to confirm diagnosis^(ii) radiotherapy and chemotherapy^(d) prognosis: 90% five year survival if respond Q48=LACRIMAL TUMOURS^ ^ A48=I Fifty per cent are inflammations and lymphoid proliferations^2 Pleomorphic adenoma (benign mixed cell tumour): (a) tumour of epithelial origin^ ^(b) 20-60 years^(c) painless, usually with long history (> 1 year)^(d) palpable hard nodular mass^(e) non-axial proptosis; reduced ocular movements; astigmatism^(f) local pressure changes on CT scan (moulding)^(g) histology: components of epithelial, myoepithelial, and connective tissue; irregular tubular formation with double layer epithelium; myxoid stroma; pseudocapsule management: biopsy contraindicated; en bloc resection prognosis: good if removed without rupturing the pseudocapsule^ ^ ^3 Carcinoma:^(a) malignant tumours of epithelial origin^(b) painful, usually short history (<< 1 year)^(c) + sensory loss over distribution of lacrimal nerve^(d) local bony erosion on radiograph^(e) types: adenoid cystic, adenocarcinoma, and mucoepidermoid^(f) management:^(i) exclude infection with a 2 week course of antibiotics^(ii) biopsy if no improvement^(iii) radical local resection and radiotherapy^(g) prognosis poor Q49=LOCAL SPREAD FROM ADJACENT STRUCTURES^ A49=I Nasal sinus carcinomas:^(a) maxillary most common^(b) non-axial proptosis, epiphora, epistaxis, infraorbital anaesthesia^2 Neglected skin tumours:^(a) basal cell carcinoma^(b) squamous cell carcinoma^3 Extraocular spread:^(a) melanoma^(b) retinoblastoma^4 Intracranial meningioma^5 Nasopharyngeal carcinoma Q50=METASTATIC TUMOUR^ ^ A50=Any systemic carcinoma can metastasise to the orbit. Proptosis, pain, and bony destruction common to all.^1 Neuroblastoma:^(a) childhood^(b) 40% develop orbital metastases (c) acute proptosis and lid ecchymosis (d) urinary vanillylmandelic acid raised^2 Acute leukaemia: may be the present with deposit in orbit (chloroma)^3 Breast: most common metastasis in women; scirrhous carcinoma may develop enophthalmos^4 Bronchogenic carcinoma: most common metastasis in men^5 Order of frequency (site of spread): (a) breast (orbital fat) (b) lung^(c) prostate (bone)^(d) melanoma (extraocular muscle)^(e) gut^(f) kidney^ Q51=CYSTIC LESIONS^ ^ A51=I Dermoids:^ ^(a) clinical features:^(i) children^(ii) common, painless, slow growing^(iii) upper, outer quadrant most common^(iv) dermal structures trapped along suture lines during develop-ment; may extend intracranially^(b) complications:^(i) erosion to anterior cranial fossa^(ii) ulceration, infection, rupture, chronic sinus formation^(c) management: excision in all cases as leakage occurs resulting in^inflammation^ ^2 Mucocele of nasal sinuses:^(a) develops from chronic sinus infection with obstruction to draining ostium^(b) frontal and ethmoid sinuses most commonly affected^(c) may invade orbit leading to proptosis^(d) management involves drainage and obliteration of the sinus^ ^3 Lipoepidermoid:^(a) benign mass usually laterally with subconjunctival component^(b) may have cilia in conjunctival component^(c) management: conservative or excision of anterior element with care^not to damage lacrimal ducrules^ ^4 Cholesterol granuloma: post-traumatic; inflammatory reaction to dena-tured intradiploic haemorrhage Q52=Downward Globe Displacement A52=Thyroid^NF^Lymphoma^Fronatl mucocele^Fibrous Dysplasia^Neuroblastoma^Schwannoma^Subperiosteal hematoma Q53=Upward Globe Displacement^ A53=Max Sinus tumor^Lymphoma^Lac Sac Tumor^Metastatic tumor Q54=Lat Displacement A54=Ethmoid Mucocele^Nasopharyngeal Tumor^Lethal midline granuloma^met tumor^Lac Sac tumor Q55=Medial Globe Displacement A55=Lac fossa tumor^Sphenoid wing meningioma Q56=Freq of Lac Fossa Lesions A56=Dacryoadenitis 51%^Pleomorphic adenoma 18%^Reactive lymphoid hyperplasia 9%^Adenoid cystic carcinoma 7%^Dacryops (epithelial cyst) 5%^Lymphoma 4%^Mucoepidermoid carcinoma 3%^Pleomorphic adenoma 2%^Plasmacytoid lesions 1% Q57=Lesions associated with bone destruction A57=Repartive granuloma^Aneurysmal bone cyst^Ewing's sarcoma^Wegner's Granulomatosis^Osteosarcoma^Fibropsarcoma^Histiocytosis X^Plasmaytoma^Sinusitis^Metastatic tumors^Sinus and nasopharyngeal tumors Q58=Calcified Orbital lesions A58=Phlebolith^Orbital varix^Lymphangioma^Thrombosed AV shunt^Chronic Inflammation^Malignant Lac Gland Tumors^Optic Nerve Sheath meningioma^Dermoid cyst^Mucocele walls^Fibro-osseous tumors Q59=Cystic Lesions of Orbit A59=Dermoid cysts^Conjunctival cysts^Sweat gland cysts^Microphthalmos with cyst^lacrimal gland cyst^lymphangioma^scwannoma^infectious abcesses Q60=Frequency of Vascular Lesions A60=Cav hemagioma 50%^Cap hemangioma 18%^Hemagiopericytoma 13%^Lymphangioma 10%^Orbital Varicies 5%^other 5% Q61=Frequency of Lymphoid Lesions A61=lymphoma 51%^reactive and atypical lymphoid hyperplasia 35%^leukemia 5%^plasma cell dyscrasias 5%^histiocytoses 4% Q62=Frequency of Neurogenic Lesions A62=sphenoid wing meningioma 30%^ON glioma 22%^NF 19%^schwannoma 14%^ON meningioma 11%^other 4% Q63=Origin of Metastaic tumors A63=breast 53%^prostate 11%^GI 11%^lung 4$^sarcoma and other 21% Q64=Lac Gland Evaluation A64=Schirmer's -- w/o Anesthesia 15mm <<40 yo, 10mm >40 yo^with 10mm << 40yo, 5mm >40yo^ ^Lacrima syringing^hard stop (duct) vs soft stop (canaliculus)^no reflux/ no resist --> patent^some reflux/some resist --> anat patet, physiological stenosed^all reflux --> obstructed^ ^Jones Test^I -- 5mins FA in nose cotton swab -- inaccurate^Ie -- endoscope with cobalt blue filter 95% accurate to see ^II -- irrigate with clear fluid -- FA +ve --> lower sac/duct system^FA -ve --> upper (canalicular) system ^ ^DCG -- Dacryocystography^Uses^for complete obst. when site cannot be determined clinicallly^incomplete obst when cannot localixze area of stenosis^suspect lac sac tumor to visualize filling defect^in adnexal disease to visualizr compression/deflection of sac/duct^ ^with viscous oil=macroDCG^with water soluble=digital subtraction DCG^ ^DOES NOT EVALUATE PHYSIOLOGIC FUNCTION^ ^CT or CT-DCG^U/S esp biomcroscopy^endoscopy -- nose^ ^Lac scan^PHYSIOLOGIC TEST^technetium-99m pertechnatate^pinhole collimater of gama camera^extent of stenosis from physilogic standpoint^lid/punctal malpositions -- evaluate flow of tears^small rad dose