Ocular Disease Flashcards
What slit lamp technique is used to evaluate corneal clarity?
Sclerotic scatter
What is the set up for sclerotic scatter?
60 degrees
Light at the limbus
Parallel piped beam
Naked eye
Which slit lamp technique is used to estimate depth?
Optic section
Which slit lamp technique is used to evaluate corneal endothelium?
Specular reflection
What type of illumination is used to evaluate non-opaque corneal lesions?
Indirect illumination
What filter is used to help detect Fleischer rings?
Cobalt blue - no NaFl
-iron rings appear black
Which has a worse prognosis, alkali burns or acidic burns? Why?
Alkali burns - they raise tissue pH, breaking down fatty acids in the cell membrane for faster penetration
What is the most common cause of alkali burns?
Calcium hydroxide
In a burn, limbal blanching is an indicator of what?
Ischemia
What is the typical sign of a corneal abrasion?
Corneal defect w/o underlying SEI
Hyphema is usually a result of trauma to what structures?
Iris or ciliary body
What exam procedures are contraindicated in a pt with hyphema?
Gonio
Scleral depression
-until 1 months post injury
What is hyphema?
Blood in the AC
What is a Vossius ring?
Pigment ring on the anterior lens, typically due to trauma (iris touching lens)
What may cause an increase in IOP in a pt with hyphema?
RBCs clogging the TM
How should pts with significant hyphema be instructed to sleep?
Head elevated at 30 degrees
If an idiopathic hyphema presents to you, what tests should be ordered?
CBC
Prothrombin time (PT/PTT)
Sickle cell screen
Ask about NSAID use
In orbital wall fractures, what muscle is most likely trapped, causing diplopia in what gaze?
Inferior rectus
Upgaze
When may gonioscopy be performed after an orbital fracture?
4 weeks after (same for scleral depression)
Commotio Retinae is typically due to trauma, and is a disruption of what parts of the retina?
RPE and PR outer segments
How long does commotio retinae take to resolve?
Typically 24-48 hours
What is Berlin’s edema?
Commotio retinae in the macula
Commotio retinae may or may not be accompanied by what two other conditions that often result from trauma?
Retinal hemorrhages
Choroidal rupture
What is iridodialysis?
Disinsertion of the iris root from the ciliary body
What type of glaucoma may occur following iridodialysis?
Angle recession glaucoma - possible TM damage
What does iridodialysis typically look like on SLE?
Peripheral iris hole, best seen with retroillumination
Purtscher’s retinopathy is commonly associated with what?
Chest-compressing trauma
What characterizes Purtscher’s retinopathy?
Diffuse retinal hemorrhages
Exudates
CWS
What is the typical appearance of choroidal rupture?
Single or multiple areas of subretinal hemorrhage, usually within the temporal posterior pole
Crescent shaped tears concentric to the ONH
Choroidal rupture is associated with a long term risk of development of what?
CNVM at the margins of the tear
Which ocular structure weakens with age, and may allow orbital fat to prolapse?
Septum
Severe prolapsed orbital fat may be a contributing factor to what ocular surface condition?
Exposure keratopathy - lid malposition
What is the typical demographic and time period of preseptal cellulitis?
Children/young adults
Winter months
What are the top 3 causes of preseptal cellulitls?
Ocular infection (hordeolum, dacryocystitis) Systemic infection (URI, middle ear infection) Skin trauma (insect bite, wound)
What are the signs of preseptal cellulitis?
Eyelid edema Erythema Ptosis Warmth No pain-mild tenderness Hard eyelid bump NO orbital congestion
What are the 4 most common causes of orbital cellulitis?
Sinus infection (ethmoid)
Orbital infection (dacryoadenitis, dacryocystitis)
Orbital fracture
Dental infection
What is the most common bacterial culprit of orbital cellulitis in adults?
Staph aureus
What is the most common bacterial culprit of orbital cellulitis in kids?
Haemophilus influenzae
What are the symptoms of orbital cellulitis?
Red eye Pain Decreased VA Headache Fever Malaise Reduced color vision APD Proptosis Diplopia Pain on EOM EOM restriction
What are the signs of orbital cellulitis?
Eyelid edema
Redness
Orbital cellulitis can result in what other conditions?
Cavernous sinus thrombosis
Brain abcess
Meningitis
What is the other name for Thyroid Eye Disease?
Graves’ disease
What is the typical demographic of TED?
Female (8:1)
30-40s
What is the strongest risk factor for developing TED/Graves?
Smoking
What is the pathophysiology of Graves/TED?
Autoimmune disorder
TSH antibodies attacking EOMs and orbital tissue, causing thickening and compressing the optic nerve
What are the symptoms of Graves’?
Prominent eyes Chemosis FBS Tearing Photophobia Pain Diplopia Decreased VA Color vision loss
What are the signs of Graves’?
Uni or bilateral proptosis Upper lid retraction Eyelid erythema and edema Conj/caruncle injection and edema Decreased coloar vision EOM restriction APD
In Graves’, IOP may be elevated in what gazes?
Primary
Upgaze
What is the most common cause of unilateral or bilateral proptosis in middle-aged patients?
Thyroid eye disease
What is the NO SPECS grading system of TED?
N - No signs/symptoms
O - Only signs, no symptoms
S - Soft tissue involvement (lid edema, conj chemosis)
P - Proptosis
E - EOM involvement (diplopia)
C - Corneal involvement (SPK, SLK, ulcer)
S - Sight loss (nerve compression)
What is the order of muscles affected first in TED?
Inferior rectus
Medial, superior, and lateral recti
What is Von Graefe’s sign?
Upper eyelid lag during downgaze
What is Dalrymple’s sign?
Staring eye - lid retraction
What is Kocher’s sign?
Globe lag compared to lid movement when looking up
What tests can be used for TED diagnosis?
Forced ductions CT/MRI Exophthalmometry VF for optic nerve compression T3/T4/TSH
Carotid-Cavernous fistula results from an abnormal communication between what?
Arterial and venous systems
Carotid-cavernous fistula most commonly results from what?
Closed head trauma
What is the clinical triad of carotid-cavernous fistula?
Chemosis
Pulsatile proptosis
Ocular bruit
What causes the carotid-cavernous fistula triad?
High pressure blood from carotid building in the cavernous sinus, impeding the return of venous blood back to the cavernous sinus
Beyond the typical triad, what are the other signs of carotid-cavernous fistula?
Episcleral venous congestion Periorbital tissue swelling Elevated IOP Diplopia (CN 3, 4, or 6 palsy) Loss of lid/face sensation on affected side (CN 5 palsy)
What is the most common benign orbital tumor in adults?
Cavernous hemangioma
What is the typical demographic for cavernous hemangioma?
More common in females
30-50’s
What characterizes cavernous hemangioma?
Progressive, painless, unilateral proptosis
Where does a cavernous hemangioma typically arise?
Within the muscle cone
What is the most common benign orbital tumor in children?
Capillary hemangioma
What is the most common primary pediatric orbital malignancy?
Rhabdomyosarcoma
What sign does rhabdomyosarcoma produce?
Progressive unilateral proptosis
What is the most common secondary pediatric orbital malignancy?
Neuroblastoma
What is the most common intrinsic tumor of the optic nerve?
Optic nerve glioma
Infant cases of optic nerve glioma are associated with what in 30-50% of cases?
Neurofibromatosis type 1
What is the most common benign brain tumor?
Meningioma
What is the typical demographic of a meningioma?
Middle aged women
What is the typical demographic of lymphoma?
50-70 years old
What are the characteristics of lymphoma?
APD
Insidious progressive proptosis
VA loss
What is a neurofibroma?
Benign, yellow-white tumor of astrocytes
What is the typical demographic of a neurofibroma?
Young to middle-aged adults
Where is a neurofibroma typically seen on a CT?
Superior orbit
What is a neurilemmoma?
Benign tumor of Schwann cells
A neurilemmoma is most commonly found in what age group?
Young to middle aged