Eye Flashcards
What can be a complication of proptosis?
- Chronic corneal ulcer and/or infection from exposure to air
What is the most common cause of unilateral or bilateral exophthalmos?
- Graves
What causes exophthalmos in Graves?
- Enlargement of the extraocular muscles with non-granulomatous inflammation (tendons and adipose not inflamed)
- Increased glycosaminoglycans
- Endomysial fibrosis
What are some complications of Graves?
- Visual loss due to compression of optic nerve
- Corneal complications due to exposure
What happens in idiopathic orbital inflammation (pseudotumor)?
- Lymphs, plasma cells, and eosinophils infiltrate
- Orbital fat and tendons replaced by fibrosis
Where around eyes does idiopathic orbital inflammation affect?
- Lacrimal only
- Extraocular muscles
- Tendon capsule
- Fascial layer
How is Graves distinguished from pseudotumor?
- In pseudotumor, the tendons and adipose have fibrosis
What are some causes of orbital inflammatory disease?
- Sinus infection can spread
- Granulomatosis with polyangiitis
- Sarcoid
What is seen in sarcoid that causes orbital inflammatory disease?
- Systemic disease
- Granulomatous uveitis
- Sympathetic ophthalmia
What do you see on ophthalmic exam in sarcoid?
- “Mutton fat” in anterior segment and keratic ppt
- “Candle wax drippings” on ophthalmic exam, perivascular inflammation of retina
What is blepharitis?
- Chronic inflammation of eyelid margin
What is a chalazion?
- Lipid extravasated into tissue provokes granulomatous response –> lipogranuloma
What are some neoplasms that affect the eyelid?
- Basal cell carcinoma
- Sebaceous carcinoma
- Melanoma
- Kaposi sarcoma
Who mainly has basal cell carcinoma of the eyelid?
- Younger patients with a lot of sun exposure
- Lower eyelid most common location
What does basal cell carcinoma of the eyelid look like?
- Pearly nodules
- Telangiectatic vessels
- Central ulcer (rodent ulcer)
- Rolled edges
What is a sebaceous carcinoma?
- Common as squamous cell carcinoma of eyelid
- Chalazion that returns after treatment
What is seen in sebaceous carcinoma?
- Pagetoid spread –> intraepithelial spread
- Nuclei larger, increased pleomorphic, hyperchromatic and more atypical than BCC
What stain is used to help identify sebaceous carcinoma?
- Oil Red O –> fat stain but only used on frozen tissue
Where do sebaceous carcinomas most likely to metz too?
- Regional LN (parotid and submandibular)
- Lung
- Liver
- Brain
- Skull
What are sebaceous carcinomas associated with?
- Muir-Torre syndrome –> skin tumors in association with internal cancers
What is the palpebral conjunctiva?
- Tightly tethered to tarsus
- Papillary folds with allergic and bacterial conjunctivitis
What is the fornix?
- Contains accessory lacrimal tissue and lymphoid tissue
What does the fornix contain?
- Pseudostratified columnar epith rich in goblet cells
What is seen in viral conjunctivitis?
- Enlarged lymphoid follicles
What is the bulbar conjunctiva?
- Covers the surface of the eye
What epithelial covers the bulbar conjunctiva?
- Non Keratinizing stratified squamous
What are some causes of conjunctival scarring?
- Chlamydia trachomatis
- Exposure of the ocular surface to caustic alkalis or as a sequela to ocular cicatricial pemphigoid
- Dry eye –> reduction in number of goblet cells
- Iatrogenic damage –> drug and/or surgery
What is a pinguecula?
- Limbus, small yellowish submucosal elevation near iris
What causes a pinguecula?
- Thin epithelium
- Fragmented stromal collagen
- Basophilic degeneration
- May contain sun induced SCC or melanoma
Does a pinguecula affect vision?
- NO
What is a pterygium?
- Similar to pinguecula but encroaches on the cornea in winglike fashion
What is seen in conjunctival melanoma?
- Unilateral and in fair complexion individuals in middle age
What mutation is a big cause of conjunctival melanoma?
- BRAF V600
What is a precursor lesion of conjunctival melanoma?
- Primary acquired melanosis, with atypia
- 50-90% when untreated develop melanoma
What are some causes of blue sclera?
- Scleritis thins sclera
- Increased intraocular pressure thins sclera
- Osteogenesis imperfecta
- Congenital melanosis oculi, accompanied by periocular cutaneous pigmentation –> nevus of ota
Why is a corneal transplant able to be done so often?
- Lacks blood vessels and lymphatics
What are some reasons for a corneal transplant rejection?
- Loss of endothelial cells and subsequent corneal edema
What is a hypopyon?
- Exudate and cells leaking from iris and ciliary body vessels into anterior chamber
What are some bacteria that can infect the cornea?
- S. aureus
- S. pneumoniae
- P. aeruginosa
- Enterobacteriaceae
What is acanthamoebic keratitis?
- May lead to corneal ulcers or even blindness
- Most often in people who wear contact lens and do not properly disinfect their lenses
How can people prevent acanthomoebic keratitis?
- Use hydrogen peroxide based solutions
What is the treatment for acanthamoebic keretitis?
- No single medication eliminates both trophozoite and cystic forms
- Corneal transplant
What is granulomatous amoebic encephalitis? What does it cause?
- Often in immunosuppressed patients
- Amoebae enter body through open wound
- Can cause massive brain swelling resulting in death
What is seen in herpes simplex virus keratitis?
- Dendrite –> linear arborizing pattern of opacification and swelling of epithelial cells
- Infected cells may coalesce to form multinucleated giant cells
What does a giemsa stain reveal in HSV keratitis?
- Intranuclear viral inclusions
How does HSV keratitis affect descemets membrane?
- Granulomatous reaction –> histologic hallmark
What are some causes of corneal degenerations?
- Inflammation, maturity, or systemic disease
- May see deposition, thinning, or vascularization
How do you differentiate between corneal degenerations and dystrophies?
- Degenerations are not familial while dystrophies are
What is calcific band keratopathy?
- Calcium deposition in bowman layer
What is the source of calcific band keratopathy?
- Chronic uveitis, especially with juvenile rheumatoid arthritis
What causes actinic band keratopathy?
- Chronic exposure to high amount of UV light
- Extensive solar elastosis develops in superficial layers of corneal collagen in sun-exposed interpalpreal fissure
What is keratoconus associated with?
- Downs
- Marfans
- Atopic disorders
What is keratoconus?
- Progressive bilateral centra ectasia of cornea with anterior protrusion of cornea
- Causes irregular astigmatism that is NOT correctable with glasses
What can help correct keratoconus?
- Rigid contact lenses
What is the histologic hallmark of keratoconus?
- Thinning of the cornea with breaks in the bowman layer
What is fuchs dystrophy?
- Descemet’s diffusely thickened with focal anvil-shaped excrescences of basement membranes material protruding into anterior chamber
What is seen in fuchs dystrophy?
- Endothelial cells sparse or absent –> leading cause of bullous keratopathy
What is pseudophakic bullous keratopathy?
- Decrease in endothelial cells following cataract surgery
What is the most common cause of corneal transplants in the US?
- Fuchs dystrophy
What is a cataract?
- Lenticular opacities that may be congenital or acquired
What are some risk factors for cataracts?
- DM
- Wilson disease
- Atopic dermatitis
- Drugs
- Radiation
- Trauma
What is nuclear sclerosis?
- Age related cataracts typically results from opacification of the lens nucleus
What is a posterior subcapsular cataract?
- Migration of the lens epithelium posterior to the lens equator
What is phacolysis?
- HMW proteins form liquefied lens cortex leaks through the lens capsule, may clog the trabecular meshwork and increases intraocular pressure
- Form of secondary open angle glaucoma
What is glaucoma?
- Collection of diseases with distinctive changes in the visual field and in the cup of the optic nerve
What is glaucoma most associated with?
- Increased intraocular pressure
What are some risk factors of glaucoma?
- Age
- Race
- Family history
- DM
- HTN
- Trauma
- Prolonged corticosteroid use
What is open angle glaucoma?
- Complete open access to trabecular meshwork
- Increased resistance to aqueous outflow causing increased intraocular pressure
What is angle closure glaucoma?
- Peripheral zone of iris adheres to trabecular meshwork which physically impedes outflow of fluid
What are the two types of open angle glaucoma?
- Primary –> angle is open and few structural changes
- Secondary –> Pseudoexfoliation most common form; deposition of fibrillary material throughout anterior segment
What are the two types of angle closure glaucoma?
- Primary –> pupillary block; iris bombe
- Secondary –> pathologic membranes over iris causing occlusions
What is seen in primary angle closure glaucoma?
- Increased intraocular pressure damages lens epithelial which causes opacities, plus corneal edema and bullous keratopathy
What is seen in secondary angle closure glaucoma?
- Chronic retina ischemica (increase in VEGF) –> neovascular glaucoma
What is an anterior synechiae?
- Adhesions between iris and trabecular meshwork
What do anterior synechiae cause?
- Increased intraocular pressure causing optic nerve damage
- Anterior subcapsular cataract –> decreased aqueous causing fibrous metaplasia of lens epithelial
What is a posterior synechiae?
- Adhesions between iris and anterior surface of lens
What is endophthalmitis?
- Inflammation in vitreous humor
What are some causes of endophthalmitis?
- Exogenous –> originating in environment that gains access to interior of eye
- Endogenous –> enters hematogenously
What could suppurative inflammation of the vitreous humor cause?
- A few hours of it could cause irreversible retinal injury
What is panophthalmitis?
- Interior inflammation also involving retina, choroid, sclera, and extends into orbit
What is uveitis?
- Any type of inflammation involving uvea (iris, choroid, and ciliary body)
What are some causes of posterior segment uveitis?
- Infection (P. carinii)
- Idiopathic
- Autoimmune
What is seen in granulomatous uveitis?
- Sarcoidosis
- “Candle wax drippings”
What is sympathetic ophthalmia?
- Noninfectious uveitis limited to eye
- Bilateral granulomatous inflammation of all components of uvea –> no plasma cells and eosinophils
- Complicates penetrating eye injury
What is the treatment for sympathetic ophthalmia?
- Systemic immunosuppressive agents
What is the most common primary intraocular malignancy in adults?
- Uveal melanoma
What are some deposits of uveal melanoma?
- No link to UV light
- Genetic events are required for development of melanoma
What are some mutations seen in uveal melanoma?
- GNAQ and GNA11 GPCRs
- May have something to do with BAP1 on chr 3
What is the worst kind of uveal melanoma?
- Epithelioid –> spherical, greater cytological atypically
What is seen in epithelioid melanoma?
- Large nuclei
- Prominent nucleoli
- Infiltrating plasma cells and lymphs
Where is the first place uveal melanoma metz to?
- Livers hematogenously
What is retinal detachment?
- Separation of neurosensory retina from retinal pigment epithelium
What is retinitis pigmentosa?
- Hereditary retinal degeneration –> X-linked rec
- Age of onset correlates with inheritance pattern
What does retinitis pigmentosa affect?
- Rods and cones of RPE
What happens when the vitreous liquifies?
- Collapses and causes floaters
What is posterior vitreous detachment?
- Posterior hyaloid separates from neurosensory retina due to aging
What is rhegmatogenous retinal detachment?
- Full thickness retinal defect?
How is rhegmatogenous retinal detachment treated?
- Scleral buckling –> application of strips of silicon to the surface of the eye
- Vitrectomy –> removal of vitreous material (last resort)
What is a non rhegmatogenous retinal detachment?
- Retinal detachment without retinal break
- Retinal detachments associated with choroidal tumors and malignant hypertension
What is retinal arteriolosclerosis?
- Thickened arteriolar walls appear narrowed
- Color of the blood column varies from bright red to copper to silver
What can happen in retinal arteriolosclerosis?
- Arteriole may compress the vein at points where vessels cross due to sharing a common adventitial sheath
- This venous stasis may precipitate occlusions of the retinal vein branches
What happens in malignant hypertension?
- Retinal and choroid vessels damaged
- Macular star is seen
What is the macular star seen in malignant hypertension?
- Poke-like arrangement of exudate in the macula
What are elschnig spots?
- Damaged choroidal vessels causing focal choroidal infarcts
What are cytoid bodies that may be seen in malignant hypertension?
- Accumulation of mitochondria at the swollen ends of damaged axons
- Found in the nerve fiber layer infarct of a “cotton wool spot”
What is the main histologic hallmark of diabetic retinopathy?
- Thickening of the basement membrane of the par plicata of the ciliary body
What occurs in non-proliferative diabetic retinopathy?
- Basement membrane of retinal blood vessels thickened
- May have microaneurysms
- Macular edema –> may cause vision loss
- Exudates
- Micro-occlusions
Where do the exudate accumulate in diabetic retinopathy?
- Outer plexiform layer, due to vascular changes
What occurs in proliferative diabetic retinopathy?
- New vessels sprouting from optic nerve head or surface of retina
- “Retinal neovascularization” –> new branches breach internal limiting membrane of retina
What are some complications of diabetic retinopathy?
- Hemorrhage from neovascularization
- Posterior vitreous detachment
- Retinal detachment
- Neovascular glaucoma
What is the treatment for diabetic retinopathy?
- Ablating nonperfused retina by laser photocoagulation or cryopexy regression of both retinal and iris neovascularization
- Injection of VEGF inhibitors into vitreous have been used
How does retinopathy of prematurity occur?
- In premature infants who are treated with oxygen, immature retinal vessels in the temporal retinal periphery constrict, rendering the retinal tissue distal to this zone ischemic
What are some complications of retinopathy of prematurity?
- Neovascularization of retina and vitreous –> proliferation of new vessels between vascularized and avascular peripheral retina
- Fibrovascular proliferation into vitreous causing tractional retinal detachment
What is dry age related macular degeneration?
- No neoangiogenesis
- Vision loss may be severe
- No treatment
What is wet age related macular degeneration?
- Choroidal neovascularization
- Tx –> inject VEGF antagonists into vitreous
What gene and chromosome is responsible for retinoblastomas?
- RB on Ch 13
- Only one gene is sufficient in suppresses mutant genes but since it is so bad, the mutant gene is expressed
Where do retinoblastomas typically spread?
- Brain
- Bone marrow
- RARELY to the lungs
What association is seen with trilateral retinoblastoma?
- Pinealoblastoma
What does a retinoblastoma look like histologically?
- Round, oval, or spindle shaped hyperchromatic nuclei with scant cytoplasm
- Necrosis with calcification and perivascular cuffs of viable tumor cells
What rosettes are seen in retinoblastomas?
- Flexner-Wintersteiner –> central lumen lined by columnar tumor cells that contain peripherally oriented nuclei
What determines prognosis with retinoblastomas?
- Affected by extraocular extension and invasion of optic nerve and choroidal invasion
What is the treatment for retinoblastomas?
- After chemoreduction, tumors may be obliterated with laser treatment or cryopexy
What are some secondary effects of retinoblastomas?
- Pseudohypopyon
- White reflex
- Proptosis
What is anterior ischemic optic neuropathy?
- Spectrum of injuries to the optic nerve varying from ischemia to infarction
- Transient partial interruptions of blood flow cause transient loss of vision
- Total interruption is due to optic nerve infarct
What happens to the optic nerve in an infarct?
- Does not regenerate so vision loss is permanent
What should you think about if there is bilateral swelling of optic nerve?
- Increased intracranial pressure
What should you think about if there is unilateral papilledema?
- Compression of the nerve
What is normal tension glaucoma?
- Small group that develops visual field and optic nerve changes typical of glaucoma with normal
What is buphthalmos?
- Increased intraocular pressure in infants causing diffuse enlargement of eye
What is optic neuritis?
- Loss of vision secondary to demyelination of optic nerve
- Seen in MS
What is phthisis bulbi?
- End stage eye –> eye is small and internally disorganized
- Could be due to trauma, intraocular inflammation, chronic retinal detachment
