Plastics/Orbit Flashcards Preview

ChM > Plastics/Orbit > Flashcards

Flashcards in Plastics/Orbit Deck (99):
1

What divides the orbital and palpebral lobe of the lacrimal gland

Lateral horn of the levator aponeurosis

2

accessory lacrimal glands

Krause - superior and lower conj fonix Wolfring - Upper lid superior tarsal border

3

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.

4

Approach to tearing

Either overproduction or impaired drainiage.

5

Over production of tears

Neurologic (VII abberant regeneration - crocodile tears) Ocular Surface Lid and Lash Malposition Inflammation (uveitis)

6

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)

7

Test for laxity, how many mm= positive distraction Snap Back test, how long hanging out without blink = positive snap

8mm, 6 sec

8

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

9

Which bacteria are responsible for canaliculuitis

Actinomyces (anerobic gram + bacilli, sensitive to Pen, sulfur granules) , fusarium and nocardia

10

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)

11

Orbital hemorrhage

Trauma Orbital surgery Bleeding diathesis Retro-bulbar anaesthetic injection Vascular tumors (varix, hemangioma, lymphangioma)

12

Proptosis - broad categories

Orbital mass/inflammation Orbital hemorrhage Axial proptosis (e.g. high myopia) Lid retraction Contralateral enophthalmos

13

Proptosis in childhood (broad categories)

Orbital mass/inflammation Orbital hemorrhage Axial proptosis (e.g. high myopia, congenital glaucoma) Lid retraction Contralateral enophthalmos

14

Enlarged EOM

Thyroid Myositis, IOI Hematoma/bruising Mets to muscle Inflammatory infiltration (e.g. sarcoid?) CCF

15

Bilateral proptosis

Thyroid Axial length Bilateral lid retraction CCF Inflammatory (wegener, sarcoid, IOI, myositis) Structural (craniofacial) Neoplastic (lymphoma, leukemia, neuroblastoma, mets, glioma)

16

Pseudo-proptosis

Lid retraction Contralateral enophthalmos Contralateral ptosis High axial length (myopia, cong glaucoma) Assymetric orbit size (e.g. craniofacial disorders)

17

Pulsatile proptosis

Brain: (sphenoid wing gone) - mucocele - encephalocele - NF1 - removal of orbital roof (surgical) - lytic bone lesions (?) Vascular - CCF - dural cavernous fistula - varix

18

Hyperostosis

Fibrous dysplasia Ossifying fibroma paget's disease

19

Lytic skull lesions

Metastatic dz Histiocytosis X (Langerhans histiocytosis)

20

Triad of proptosis, lytic bone lesions, DI

Hand Schuller Christian Dz (type of histiocytosis X)

21

Bloody tears

Canalicular/NLD: - trauma - tumor - infection - inflammation - iatrogenic (after probing, DCR) - foreign body

22

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)

23

Which MRI is best for MS?

T2

24

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)

25

Calcified orbital mass

Dermoid Cavernous hemangioma Meningioma Phlebolith

26

Enophthalmos

Pseudo - other side proptotic Breast Ca mets (only orbital met to cause enophthalmos) Floor # Phthisis Trauma (ruptured globe)

27

Cystic orbital lesions

Dermoid Epidermoid Pleimorphic adenoma

28

Blue cell tumor

B-cell lymphoma: - MALT - diffuse large B cell - Merkel cell Leukemia Neuroblastoma Rhabdomyosarcoma RB Ewing's sarcoma Wilm's tumor (kidney)

29

5 types of adenoid cystic ca (on histology)

(CBC, ST) - Tubular - Sclerosing - Comedo - Cribiform - Basaloid

30

Sinus things that come to the orbit

- Mucocele - Burkitt's lymphoma - scc, mucoepidermoid ca

31

DDx of major orbital inflammation

Infectious Inflammatory - IOI - Sarcoid - Wegener - RA - SLE - PAN - GCA

32

Orbital metastatic tumors

Adults: Breast, lung, ovary Kids: neuroblastoma, Ewing's sarcoma

33

6 paraneoplastic syndromes in the eye

MAR CAR BDUMP Eaton Lambert Horner's Opsoclonus

34

5 cancers that give paraneoplastic syndromes

Lung ca Breast Ovary Neuroblastoma Melanoma (there are others)

35

Orbital neural tumors

Schwannoma Glioma Meningioma

36

Orbital mesenchymal tumors

Fibrous histiocytosis Rhabdo Fibrous dysplasia Ossifying fibroma Liposarcoma, fibrosarcoma, chondrosarcoma, osteosarcoma

37

Orbital lymphoid tumors

Benign lymphoproliferative hyperplasia Lymphoma: - MALT - CLL - follicular - large B cell - Burkitt's lymphoma

38

Xanthogranuloma (4 syndromes)

JXG Necrobiotic xanthogranuloma Erdheim Chester Adult onset xanthugranuloma

39

Sources of orbital cellulitis

Trauma Extension from skin Extension from sinus dz Extension from lacrimal drainage system (canaliculitis, dacryocystitis) Dental Endogenous

40

Lacrimal gland tumors

Infectious Inflammatory: sarcoid, Wegener, idiopathic, Sjogren's, PAN, GCA Neoplastic benign: pleimorphic adenoma Neoplastic malignant: malignant mixed tumor, adenoid cystic ca Systemic syndromes: Sjogren, Muciklz (sarcoid)

41

Orbital vacular tumors

Cavernous hemangioma Capillary hemangioma Lymphangioma Varix Hemangiopericytoma AV fistula (CCF, DCF)

42

Subperiosteal orbital abscess - indications for surgical drainage in children

- >9 years old - ON involvement - frontal sinusitis - non-medial location of abscess - large abscess - recurrent/chronic infection - dental source - gas on CT (anaerobic)

43

Punctal stenosis - risk factors

Female Age Trauma Inflammation (OCP, SJS) Tumor

44

Most common orbital mets in men and women

Women: breast Men: lung

45

Canalicular stenosis - risk factors

Female Age Trauma Infection Inflammation Tumor Radiation, dacryolith, allergy, canaliculitis

46

NLDO obstruction ddx

Congenital Trauma Infection Tumor (lymphoma, SCC, mucoepidermoid) Nasal polyp, nasal cancer Sinuz dz Granulomatous inflammation (sarcoid, wegener)

47

Risks of retro-bulbar anaesthesia

Retro-bulbar hemorrhage Globe perforation ON damage Brainstem anaesthesia

48

What are the symptoms of brainstem anaesthesia

Decreased RR LOC Hypotension, decreased HR

49

How do you manage brainstem anaesthesia

Supportive. Call code, intubate, etc. ABC's

50

Ddx of retro-orbital mass (behind the globe)

Glioma Meningioma Abscess Inflammatory (IOI, other) AV fistula, varix Mets

51

Ddx of supero-nasal orbital mass

Most likely: Mucocele, encephalocele Sinus carcinoma Less common: Dermoid, epidermoid Vascular Inflammatory

52

Ddx of infero-nasal orbital mass

Dacryocystitis Mucocele Canalicular/NLD/sac tumor

53

Ddx of supero-lateral orbital mass

Dermoid Epidermoid Lipodermoid Enlarged lacrimal gland (inflammation, tumor, infection)

54

Ddx of bilateral orbital proptosis

TED Axial myopia Bilateral lid retraction Metastatic disease (not breast) Bilateral vascular or other tumors Bilateral CCF

55

Which sinus is first to aerate

Ethmoid

56

When does the frontal sinus aerate

6 years old

57

When does the sphenoid sinus aerate

Puberty

58

Which is the largest sinus

Maxillary

59

Where does the annulus of zinn originate from

Peri-osteum

60

What tissue does the orbital septum come from

Peri-osteum

61

What 3 things are behind the septum

- orbital lobe of lacrimal gland - lateral canthal tendon - SO trochlea

62

Where does the septum insert into the levator (relative to the tarsus)

2-5 mm above tarsus (in asians, somewhere further down on the tarsus)

63

Where does the levator insert into the tarsus

Inferior half of tarsus on the anterior surface

64

How long is the levator

40 mm

65

How long is the levator aponeurosis

15-20 mm

66

What is the correlate in the lower lid of Whitnall's ligament

Lockwood ligament

67

What is the correlate in the lower lid of the levator aponeurosis

capsulopalpebral fascia

68

What is the correlate in the lower lid of Muller's

Inferior tarsal muscle

69

How tall is the tarsus in the upper lid? Lower lid?

10 mm upper 4 mm lower

70

What bone is fractured in a tripod #

Zygoma in 3 places. (so no IR entrapment)

71

How many LeFort's are there and what is each one

I - maxilla above teeth, no orbital involvement II - orbital floor III - orbital floor, med + lateral walls, +/- optic canal

72

What are the signs of thyroid eye disease

Lid retraction Lid lag Proptosis Decreased EOM/diplopia Corneal exposure keratitis Decreased lacrimation (inflammation of lacrimal gland) ON compromise Conj injection, congested vessels

73

What is the order of muscle involvement in TED

I'M SLO inferior > medial > superior > lateral > obliques

74

How long does the eye need to be quiet for in TED before you can offer strab surgery

6 months

75

What is the order of surgeries in TED

decompression then strab then lids

76

How long does radiation take to work in TED

2-4 weeks So if it's an acute problem (ON compromise), can't rely on radiation to quickly get it done

77

What are your options for treating the hyperthyroidism in TED

Anti-thyroid meds (methimazole, PTU) Radiation (RAI) Surgical (thyroidectomy)

78

What are your options for treating optic neuropathy in TED

Steroids (not for acutely severe dz) Radiation (takes 2-4 weeks) Decompression (most effective)

79

What are your options for treating exposure keratitis in TED

Lubrication, plugs, moisture chamber goggles, etc Tarsorrhaphy Amniotic/gunderson flap for severe

80

What workup should you do for orbital lymphoma (bx proven)

Check systemic LN's (on exam) Bone scan, Bone marrow bx CBC, SPEP CT chest/abdo Refer to heme/onc

81

What are the signs of Wallenburg's lateral medullay syndrome and what vessel obstruction causes this

PICA obstruction - ipsilateral Horner - ipsilateral facial decreased pain/temp - contralateral trunk decreased pain/temp - nystagmus, skew - dysarthria, dysphagia, dysphonia - ataxia

82

What are the pituiary hormones (ant and post)

FLAT PIG, OA Anterior: - FSH - LH - ACTH - TSH - Prolactin - GH Posterior: - Oxytocin - ADH

83

What are the features of JXLR? Visual prognosis? FA findings?

Macular schisis in NFL Sometimes peripheral retinoschisis Vitreous cells, syneuresis, hemorrhage Hyperopia 20/200 range Fa = CME that doesn't leak

84

What do oblate and prolate mean

Describes an oval ball. Depends on the axis that it spins on. Oblate = like a lentil (short and fat, spinning axis is short) Prolate = like a football (long spinning axis)

85

What are the path features of BCC

- nests of basaloid cells - peripheral pallisading - retraction of nests from surrounding stroma - little cytoplasm - rare mitotic figures

86

What are the path features of SCC

- atypical nests of squamous cells - infiltrating past BM into dermis - inter-cellular brides - perineural and lymphatic invasion

87

What are the signs and symptoms of OIS on exam and how do you treat

Symptoms: pain and decreased Va Signs: conj injection K edema AC rxn may have NVI, NVG retinal MA's delayed choroidal and retinal filling on FA Investigate with carotid doppler Endarterectomy

88

How do you do a gram stain

"VIAS" Cyrstal violet x 60 sec Iodine x 60 sec Alcohol x 5 sec Safranin x 60 sec (rise in between each one)

89

What are the features of anterior segment ischemia on exam? How do you treat it? How do you prevent it?

Pain and decreased Va Conj injection, maybe edema K edema AC rxn Rx with steroids Avoid by never doing 4 muscle surgery If you really have to, some say you can avoid it if you wait like 10 years before operating on the 4th muscle (but this doesn't seem to be consistent in the literature)

90

What machine uses the Badal principle

Lensometer

91

What are two ways to estimate Va through a dense cataract

PAM Laser interferometry (two bright dots and creates an interference pattern)

92

What are the signs of malignant hyperthermia

First: Muscle rigidity Respiratory acidosis (high CO2) / metabolic acidosis Then: High temp High HR High RR

93

How do you treat malignant hyperthermia

- stop operating - IV dantrolene - hypertenvilate with 100% O2 - cooling blanket - cooled IV NS - calcium, bicarb, glucose

94

How do you treat Bartonella

Oral doxy

95

What are the features of bartonella infection

Parinaud's (granulomatous follicular inflammation, lymph node) Neuro-retinitis (ON inflammation + macular star) Chorioretinitis

96

Explain the optics of a slit lamp (same as operating microscope)

You --> astronomical telescope --> inverting prism --> galilean telescope --> pt's eye

97

How does a Hruby lens help you see the fundus? What about handheld lenses (78, 90). What about Goldmann 3 mirror?

Cornea is high plus, so would never let you see beyond the anterior vitreous. 3 options to see farther: - contact lens to neutralise K power (Goldmann) - high minus lens to diverge the light a lot (hruby) - hand-held lens creates an astronomical telescope (inverted image - e.g. 78, 90)

98

Explain the optics of a lensometer

Target object Known lens (Badal lens) Unknown lens then astronomical telescope then your eyes (observer) The target object moves such that, after it's light passes through teh badal lens and the back vertex of the unkonwn lens, the light emerges parallel. This light then goes into the little astronomical telescope at the eyepiece, which you look into. Moving the object is linearly related to power of the unknown lens. It's linear because of the Badal lens.

99

How does a keratometer work? What are the 2 different kinds and how do they differ?

Keratometer works on the principal that the cornea is a reflecting surface of known index of refraction. It takes an object and it's reflected image, uses the relative sizes of the two to figure out the reflecting power. From there you can back-calculate to the radius of curvature (if you know the index of refraction which is the same for all eyes), and from that figure out the refractive power. It only measures the central 3 mm of the cornea. There are 2 designs: - Hemholtz - fixed object size, measures the image size - Javal-Schiotz - changes object size to get a known image size You always have to line up 2 images which is beacuse of a 'doubling prism' that it uses - something to do with minimising the effect of the person moving their eye, shaking, etc during the keratometry measurement.