The Eye Flashcards
What is proptosis? What can it lead to?
Inc in orbital contents that displaces eye; can lead to corneal ulcers or infection from exposure to air
What are 2 orbital inflammatory diseases?
- Thyroid disease like Graves
- Idiopathic orbital inflammation
What happens to the eye in Graves disease?
Does this affect adipose tissue?
Enlargement of extraocular muscles w non-granulomatous inflammation
Note: Adipose tissue is NOT inflammed
What happens to the eye in idiopathic orbital inflammation/psuedotumor?
Does this affect adipose tissue?
Lymphocytes, plasma cells, eosinophils infiltrate
Orbital fat and tendons are replaced by fibrosis
What are the 3 things present in idiopathic orbital inflammation that differentiates it from Graves disease?
IOI will include eosinophils, adipose tissue (fibrosis), and chronic inflammatory cells
What causes orbital inflammatory disease? (3)
- Sinus infection that spreads to orbit esp in immunosuppressed or DKA pts
- Granulomatosis e polyangiitis (Wegners)
- Sarcoid: May produce bilateral granulomatous inflammation secondary to penetrating injury
What are 2 unique signs of sarcoid in orbital inflammatory disease?
- “Mutton fat” in anterior segment (keratic precipitates on cornea)
- “Candle wax drippings” on ophthalmic exam, perivascular inflammation of retina
Where does eye get dispalced when lacrimal gland is involved?
Inferiorly and medially
Two common neoplasms of the orbit?
Mostly vascular in origin
- Capillary hemangioma (infancy & early childhood)
- Cavernous hemangioma (adults)
What is blepharitis?
What is chalazion?
- Blepharitis: Chronic inflammation of eyelid margin
- Chalazion: Lipid extravasated into tissue provokes granulomatous response -> Lipogranuloma
Two common neoplasms of the eyelid?
- Basal cell carcinoma
- Sebaceous carcinoma
What is the most common malignant tumor of periocular skin?
Basal cell carcinoma
- More common in younger pts w sun-exposed skin
What are some characteristics of a BCC tumor?
- Pearly nodules
- Telangiectatic vessels
- Central ulcer
- Rolled edges
Common histo in BCC?
Nests of cells that show peripheral palisading
- Look for blue coloring below the epidermis
What is one way to differentiate between a chalazion and a sebaceous carcinoma?
Chalazion should not return after removal; if it does, think sebaceous carcinoma
How do sebaceous carcinomas spread?
What is a histo characteristic?
Rolls through BM and spreads in epidermis (intraepithelial or bowenoid spread)
Foamy cytoplasm
What stain would you use for a sebaceous carcinoma?
Oil Red O (fat stain)
Where are common sites of metastasis for a sebaceous carcinoma?
Regional lymph nodes, lung, liver, brain & skull
What will be histo characteristics of squamous cell carcinoma?
Full thickness atypia w loss of polarity and keratin pearls in substantia propria
What is a common type of lymphoma in the eye/conjunctiva?
B-cell lymphoma
Where is a common site of lymphatic spread w tumors in the eyelid or conjunctiva?
Parotid and submandibular nodes
Generally, what are pingueculas & pterygiums?
Submucosal elevations of the conjunctiva d/t actinic damage (sun)
Between pingueculas & pterygiums, which can lead to cancer
Pingueculas can lead to SCC or melanoma
Pterygium are unlikely to lead to cancers
Between pingueculas & pterygiums, which can impair vision?
Pterygiums can lead to visual impairment; encroaches on cornea in a wing-like fashion– excise when it threatens visual axis
Pingueculas do not lead to visual impairment
Where do we the following grow:
- Junctional nevus
- Compound nevus
- Intradermal nevus
- Junctional: Epidermal nests that grow along dermo-epidermal junction
- Compound: Grow into underlying dermis as nests or cords
- Intradermal: No more epidermal nests
Immature vs mature nevi?
- Immature superficial nevi are larger, produce melanin, grow in nests
- Mature nevi are deeper in basal layer, smaller, produce little or no pigment, grow in cords
What do you stain corneal tissue with?
PAS to the basement membrane
What is important to note about regeneration of Descemets membrane?
What happens to it with age?
What can we note about it with Wilson’s disease?
Does not regenerate; if you damage, you will need a corneal transplant
Thickens with age
Copper deposits here to form Kayser-Fleischer ring
Why is the corneal stroma difficult to repair?
Lacks blood vessels and lymphatics (why it’s transparent!)
- Leads to lack of rejection
- Vascularization of cornea will opacify it; VEGF antagonists can be used to prevent this
What is a hypopyon?
Exudate and cells leaking from iris and ciliary body into anterior chamber (think infection OR retinoblastoma)
Most common bacteria that cause infection in the eye?
S. aureus, S. pneumoniae, P. aeruginosa, Enterobaceriaceae
What is a common cause of acanthamoebia keratitis?
Contact lenses that are not properly disinfected
- Can cause permanent visual impairment and blindness in healthy persons
Corneal degenerations vs dystrophies:
Unilateral or bilateral?
Degenerations are often unilateral but can be bilateral
Dystrophies can be either
Corneal degenerations vs dystrophies:
Inflammatory?
Degenerations can be caused by inflammation (or maturity or disease)
Dystrophies are not caused byinflammation
Corneal degenerations vs dystrophies:
Characteristics of where they affect, etc
Degenerations are often peripheral and asymmetric; can be deposition, thinning, vascularization, etc; very broad term
Dystrophies affect selective corneal layers or multiple layers; progressive over time
- Deposition of abnormal material
Corneal degenerations vs dystrophies:
Familial?
Degenerations are typically not familial
Dystrophies are familial (rare)
What are the two types of band keratopathies?
- Calcific band keratopathy: Calcium deposition in Bowman layer
- Actinic band keratopathy (aka Climatic droplet keratopathy): D/t chronic exposure to high amount of ultraviolet light
What is keratoconus and what disorders is it associated with?
What is the treatment?
Cornea bows out into more of a cone shape
- A/w Downs, Marfans, and other atopic disorders
Can be corrected with rigid contact lenses
Histo of keratoconus? What stain do you use?
Thinning of the cornea with breaks in Bowman later
- Use PAS to highlight BM
What is Fuchs dystrophy?
Descemet’s membrane is diffusely thickened w focal anvil-shaped excrescences of BM material protruding into anterior chamber; endothelial cells are sparse or absent
What is pseudophakic bullous keratopathy?
Dec in endothelial cells following cataract surgery
What is primary angle closure glaucoma?
Iris attaches to lens to block passage of aqueous humor from posterior to anterior chamber; pressure building in posterior chamber causes iris to bow forward which occludes trabecular meshwork
What is neovascular glaucoma?
Membrane grows over surface of iris which smooths surface; membrane contracts and blocks trabecular meshwork
- Closed angle glaucoma
What is exfoliation syndrome of the lens? Why is this significant with aging
Since the lens is closed system, when epithelium sloughs off it stays inside the system
- Lens size increases w age
What are some risk factors for cataracts?
- DM
- Wilson’s
- Atopic dermatitis
- Drugs (esp corticosteroids)
- Radiation
- Trauma
What is a posterior subcapsular cataract?
Migration of the lens epithelium posterior to the lens equator
What is phacolysis? What disorder can this lead to?
HMW proteins leak thru lens capsule and clog trabecular meshwork
- Leads to inc intraocular pressure which leads to phacolytic glaucoma (secondary open angle glaucoma)
What is open angle glaucoma?
What is the most common secondary cause of this?
There is no blockage to trabecular meshwork, instead there is an inc resistance to aqueous outflow which in intraocular pressure
Pseudoexfoliation is most common form; deposition of fibrillary material throughout anterior segment
What happens to the nerve fiber layer and the ganglion cell layer in glaucoma?
Both become atrophic
What are anterior synechiae?
Adhesions between iris and trabecular meshwork
What causes an anterior subcapsular cataract?
Dec aqueous humor leads to fibrous metaplasia of lens epithelium
How can you prevent formation of synechiae in pts w intraocular inflammation?
Induction of pupillary dilation and cycloplegia (paralysis of ciliary muscles)
What is endophthalmitis?
Inflammation in vitreous humor (can be exogenous like wound or endogenous)
What is panphthalmitis?
Interior inflammation involving the retina, choroid, sclera, can extend into orbit
What parts make up uvea?
Iris, choroid, ciliary body
What are some things that can cause posterior segment uveitis?
Frequently involved retinal pathology
- Infection (like pneumocystis carinii)
- Idiopathic (like sarcoid)
- Autoimmune (sympathetic ophthalmia)
What is sympathetic ophthalmia?
What cell types are involved?
How long does it take to happen?
Tx?
Damage to one eye affects both eyes
+ eosinophils, no plasma cells
Can occur weeks to years after injury
Systemic immunosuppressive agents and possible enucleation of eye
What is the most common intraocular malignancy in adults and where does it typically metastasize?
Melanoma that metastasizes to the uvea, esp choroid
What can cause uveal melanoma and how is this similar to melanoma found elsewhere?
GNAQ1 and GNAA11
- Nevi may have these mutations that rarely transform to melanoma
BAP1 predisposes to uveal melanoma among others, need genetic events for dev of melanoma
No link to UV light, no BRAF mutation
What is the prognosis with epithelioid melanoma?
BAD
Where does uveal melanoma metastasize to first?
Liver thru hematogenous spread (skips lymph nodes)
- However can spread thru sclera to conjunctiva and into lymphatics
How do outcomes compare with melanoma in the iris, ciliary body, choroid?
Melanomas in the iris tend to follow a more indolent course whereas melanomas of the ciliary body and choroid are more aggressive
Tx for uveal melanoma?
No effective treatment for metastatic melanoma
No difference in survivability with radiation vs enucleation
MAPK inhibitors have shown some effectiveness in clinical trials
What are Clark’s level and Breslow thickness in melanoma?
Clark: Anatomic level of invasion
Breslow: Thickness of tumor– important indicator for prognosis
What is retinal detachment?
Separation of neurosensory retina from RPE
What is retinitis pigmentosa?
Hereditary retinal degeneration that affects rods and cones or RPE
Blood supply of vitreous humor? What happens if there is persistent fetal vasculature?
Avascular
Persistent fetal vasculature will lead to retrolental mass; hemorrhage and neovascularization will lead to opacification of vitreous
What are “floaters” that come with age?
When the vitreous liquefies and collapses
What is posterior vitreous detachment?
Vitreous separates from neurosensory retina d/t aging (liquification)
This isn’t too bad or worrisome– unlike retinal detachment
What is rhegmatogenous retinal detachment?
Nonrhegmatogenous retinal detachment?
Full-thickness retinal defect (“retinal break”)
Non- is when there is no retinal break; a/w choroidal tumors & malignant HTN
What are reattachment options for retinal detachmnet?
- Scleral buckling
- Vitrectomy (last choice)
What is proliferative vitreoretinopathy?
Complication; epi-retinal or sub-retinal membrane formation
What does the common adventitial sheath affect with retinal arteriolosclerosis?
Retinal arterioles and veins share this sheath so in arteriolosclerosis, arteriole may compress vein at points where the vessels cross
Which intraocular vessels are damaged in malignant HTN?
Retinal and choroid vessels are damaged
What is a macular star?
Spoke-like arrangement of exudate in the macula in malignant HTN?
What can damaged choiriocapillaries lead to?
Lead to damaged RPE, which leads to exudate accumulating, which leads to retinal detachment
What are Elschnig spots?
Focal choroidal infarcts from damaged choroidal vessels
What are cytoid bodies?
Accumulation of mitochondria at the swollen ends of damaged axons; found in the nerve fiber layer infarct of a “cotton wool spot”
What is proliferative diabetic retinopathy?
New vessels sprouting from optic nerve head or surface of retina; referred to as “neovascular membrane”
What is non-proliferative diabetic retinopathy? What are some features you will see? (4)
BM of retinal blood vessels thicken
- Microaneurysm
- Macular edema
- Exudates
- Micro-occlusions (inc VEGF and intraretinal angiogenesis)
What are some complications of diabetic retinopathy? (4)
- Hemorrhage from neovascularization
- Posterior vitreous detachment
- Retinal detachment
- Neovascular glaucoma
What are some treatment options for diabetic retinopathy?
- Ablating nonperfused retina by laser photocoagulation or cryopexy (causes regression of both retinal & iris neovascularization)
- Injection of VEGF inhibitors into the vitreous has been used to treat diabetic macular edema & retinal neovascularization
What is retinopathy or prematurity (aka retrolental fibroplasia)?
The lateral aspect of the retinal periphery is incompletely vascularized but the medial aspect is vascularized
What causes retinopathy of prematurity (aka retrolental fibroplasia)?
Premature or LBW infants are treated with oxygen. This causes immature retinal vessels in the lateral periphery to constrict rendering the retinal tissue distal to this zone ischemic
- Neovascularization forms between vascularized and avascular peripheral retina –> fibrovascular proliferation into vitreous leads to tractional retinal detachment
What are the 2 forms of age-related macular degeneration?
Dry and wet
Both are a result of damage to the macula (required for central vision)
What is dry age-related macular degeneration?
No neoangiogenesis; vision loss may be severe –> deposits in Bruch membrane –> atrophy of RPE
What is wet age-related macular degeneration?
Choroidal neovascularization; vessels penetrate thru the Bruch membrane beneath RPE
What is the treatment for dry and wet age-related macular degeneration?
Dry: No treatment
Wet: Inject VEGF antagonists into vitreous
What are the two main retinal neoplasms?
- Retinoblastoma
- Retinal lymphoma
On what chromosome is the mutation for retinoblastoma? What can be said about normal gene suppression of RB alleles?
13q14
One normal gene will suppress RB allele; one abn gene is unstable & may lead to mutation of normal gene w loss of suppression
Is retinoblastoma typically unilateral or bilateral?
RB arising in context of germline mutation are often bilateral
Common sites of RB metastasis?
Brain & bone marrow
In which disorder do we see Flexner-Wintersteiner rossettes?
Retinoblastoma
What is the prognosis of RB adversely affected by?
Extraocular extension & invasion of optic nerve & choroidal invasion
Tx of RB?
Chemoreduction then laser of cryoplexy obliteration
What is anterior ischemic optic neuropathy? What are some examples that can lead to this?
Spectrum of injuries to optic nerve varying from ischemia to infarction
- Inflamed vessels, emboli, thrombosis, temporal arteritis
- Transient partial interruptions to blood flow in optic nerve (transient loss of vision)
- Total interruptions in blood flow (optic nerve infarct)
How is papilledema r/t vision?
Inc intracranial pressure –> Bilateral swelling of optic nerve head –> –? retina laterally displaced; can lead to bilateral vision loss
- Acute papilledema is not a/w vision loss
What is normal-tension glaucoma?
Small group that develops visual field and optic nerve changes typical of glaucoma but with normal intraocular pressure
Define the following:
- Buphthalmos
- Megalocornea
- Staphyloma
- Buphthalmos: Inc in intraocular pressure in infants which leads to diffuse enlargement of the eye
- Megalocornea: Enlargement of the cornea
- Staphyloma: Inc intraocular pressure in adults leading to thinning of sclera
What is optic neuritis? What disorder does this a/w?
Loss of vision secondary to demyelination of optic nerve
- Occurs w multiple sclerosis
What is phthisis bulbi?
“End-stage eye”
- Trauma, intraocular inflammation, chronic retinal detachment, and many other conditions can give rise to an eye that s both small (atrophic) and internally disorganized
