Plastics/Orbit Flashcards
What divides the orbital and palpebral lobe of the lacrimal gland
Lateral horn of the levator aponeurosis
accessory lacrimal glands
Krause - superior and lower conj fonix Wolfring - Upper lid superior tarsal border
Drainage system anatomy
punctal opening .3mm, ampulla 2mm and perpendicular to lid margin Canaliculus 8-10mm Valve of rosenmuller, 90% of the time these merge into a common canaliculus lacrimal sac is about 12-15mm vertically, the duct exits at valve of hasner under the inferior turbinate 25-30mm posterior to the to the lateral margin of the anterior nostril.
Approach to tearing
Either overproduction or impaired drainiage.
Over production of tears
Neurologic (VII abberant regeneration - crocodile tears) Ocular Surface Lid and Lash Malposition Inflammation (uveitis)
Blocked drainage
Punctal malposition - laxity/ectropion Pump Failure - CNVII palsy Punctal senosis - toxic meds (, trauma, radiation, autoimmune) Canaliculitis (think actinomyces) NLDO - Congenital vs. Aquired (Primary involutional stenosis), Secondary (infection/tumour)
Test for laxity, how many mm= positive distraction Snap Back test, how long hanging out without blink = positive snap
8mm, 6 sec
Dye disappearance ?Jones 1 test ?Jones 2 test
dye still there at 5 min = probable blockage Jones 1 = put fluorescein in the eye, use a q-tip to see if you recover any from the nose Jones 2 = put fluorescein in the, flush the punctum and now see if you get fluorescein on your nose q-tip
Which bacteria are responsible for canaliculuitis
Actinomyces (anerobic gram + bacilli, sensitive to Pen, sulfur granules) , fusarium and nocardia
U/s high reflectivity
Anything calcified in the eye: - Choroidal osteoma - ONH drusen - RB, retinocytoma - phthisis Orbital hemangioma Dermoid maybe (if it has bone/teeth in it)
Orbital hemorrhage
Trauma Orbital surgery Bleeding diathesis Retro-bulbar anaesthetic injection Vascular tumors (varix, hemangioma, lymphangioma)
Proptosis - broad categories
Orbital mass/inflammation Orbital hemorrhage Axial proptosis (e.g. high myopia) Lid retraction Contralateral enophthalmos
Proptosis in childhood (broad categories)
Orbital mass/inflammation Orbital hemorrhage Axial proptosis (e.g. high myopia, congenital glaucoma) Lid retraction Contralateral enophthalmos
Enlarged EOM
Thyroid Myositis, IOI Hematoma/bruising Mets to muscle Inflammatory infiltration (e.g. sarcoid?) CCF
Bilateral proptosis
Thyroid Axial length Bilateral lid retraction CCF Inflammatory (wegener, sarcoid, IOI, myositis) Structural (craniofacial) Neoplastic (lymphoma, leukemia, neuroblastoma, mets, glioma)
Pseudo-proptosis
Lid retraction Contralateral enophthalmos Contralateral ptosis High axial length (myopia, cong glaucoma) Assymetric orbit size (e.g. craniofacial disorders)
Pulsatile proptosis
Brain: (sphenoid wing gone) - mucocele - encephalocele - NF1 - removal of orbital roof (surgical) - lytic bone lesions (?) Vascular - CCF - dural cavernous fistula - varix
Hyperostosis
Fibrous dysplasia Ossifying fibroma paget’s disease
Lytic skull lesions
Metastatic dz Histiocytosis X (Langerhans histiocytosis)
Triad of proptosis, lytic bone lesions, DI
Hand Schuller Christian Dz (type of histiocytosis X)
Bloody tears
Canalicular/NLD: - trauma - tumor - infection - inflammation - iatrogenic (after probing, DCR) - foreign body
T1 vs T2 - how to tell apart
Vitreous is dark on T1 (think when you go into a room, it’s always dark to begin with - i.e. T1)
Which MRI is best for MS?
T2
Lid retraction/lid lag
Thyroid Aberrant regeneration 3rd Myaesthenia Congenital fibrosis CN7 palsy Iatrogenic (after ptosis/bleph repair) Parinaud’s dorsal midbrain syndrome Contralateral ptosis (herring’s law)
Calcified orbital mass
Dermoid Cavernous hemangioma Meningioma Phlebolith
Enophthalmos
Pseudo - other side proptotic Breast Ca mets (only orbital met to cause enophthalmos) Floor # Phthisis Trauma (ruptured globe)
Cystic orbital lesions
Dermoid Epidermoid Pleimorphic adenoma
Blue cell tumor
B-cell lymphoma: - MALT - diffuse large B cell - Merkel cell Leukemia Neuroblastoma Rhabdomyosarcoma RB Ewing’s sarcoma Wilm’s tumor (kidney)
5 types of adenoid cystic ca (on histology)
(CBC, ST) - Tubular - Sclerosing - Comedo - Cribiform - Basaloid
Sinus things that come to the orbit
- Mucocele - Burkitt’s lymphoma - scc, mucoepidermoid ca
DDx of major orbital inflammation
Infectious Inflammatory - IOI - Sarcoid - Wegener - RA - SLE - PAN - GCA
Orbital metastatic tumors
Adults: Breast, lung, ovary Kids: neuroblastoma, Ewing’s sarcoma
6 paraneoplastic syndromes in the eye
MAR CAR BDUMP Eaton Lambert Horner’s Opsoclonus
5 cancers that give paraneoplastic syndromes
Lung ca Breast Ovary Neuroblastoma Melanoma (there are others)
Orbital neural tumors
Schwannoma Glioma Meningioma
Orbital mesenchymal tumors
Fibrous histiocytosis Rhabdo Fibrous dysplasia Ossifying fibroma Liposarcoma, fibrosarcoma, chondrosarcoma, osteosarcoma
Orbital lymphoid tumors
Benign lymphoproliferative hyperplasia Lymphoma: - MALT - CLL - follicular - large B cell - Burkitt’s lymphoma
Xanthogranuloma (4 syndromes)
JXG Necrobiotic xanthogranuloma Erdheim Chester Adult onset xanthugranuloma
Sources of orbital cellulitis
Trauma Extension from skin Extension from sinus dz Extension from lacrimal drainage system (canaliculitis, dacryocystitis) Dental Endogenous