Eye Pathology part 1 Flashcards
Define Proptosis
Increased ORBITAL contents so the eye is displaced and the eyelid cannot cover it
If the eye is inferior and medially displaced due to Proptosis, where is the issue?
Lacrimal gland
If the eye is axially (straight forward) displaced due to Proptosis, where is the issue?
Optic Nerve
What is the most common cause of Proptosis?
Thyroid Disease = Graves
With Thyroid Disease (Graves), what is enlarged in order to cause Proptosis?
Enlargement of the extra-ocular muscles ONLY
With Thyroid Disease (Graves), what molecule is increased with the enlargement of the extra-ocular muscles that is causing proptosis?
Increased Glycosaminoglycans
Another cause of Proptosis is Idiopathic Orbital Inflammation (pseudotumor). What cells infiltrate the orbit?
Inflammatory cells + Eosinophils!
Another cause of Proptosis is Idiopathic Orbital Inflammation (pseudotumor). What does fibrosis replace in the orbit that differentiates it from Graves Disease?
Fibrosis replaces the orbital fat and tendons!!
– Graves disease only affects the extra-ocular muscles!
Sarcoid can also affect the orbit. It involves what type of inflammation and what 2 items on an opthalmic exam?
Granulomatous inflammation
- Mutton fat
- Candlewax drippings
Neoplasms of the orbit are mostly of ____ origin. List 2 and the age group that they affect.
Vascular origin
- Capillary Hemangioma = KIDS
- Cavernous Hemangioma = ADULTS
Chronic inflammation of the eyelid?
Blepharitis
What is a Chalazion and what part of the eye does it affect?
Lipogranuloma (lipid into the tissue)
– Affects the EYELID
What are the 2 most common neoplasms that affect the EYELID?
- Basal Cell Carcinoma
2. Sebaceous Carcinoma
What is the most common malignancy of the eyelid?
Basal Cell Carcinoma
Basal Cell Carcinomas often affect younger individuals with sun-exposed skin. What location of the eyelid is affected and what are the attributes of the carcinoma?
Lower eyelid
- Pearly nodule
- Telangiectasia
- Central ulcer
- Rolled edges
A pearly nodule with telangiectasia, a central ulcer and rolled edges is likely what neoplasm on the eyelid?
Basal Cell Carcinoma
What do the cells of a Basal Cell Carcinoma show histologically?
Peripheral Palisading
If a Chalazion returns after treatment on the eyelid, what is the likely neoplasm?
Sebaceous Carcinoma
Sebaceous Carcinomas commonly occur on what location of the eyelid and what type of spread do they have?
Upper eyelid
- Pagetoid spread = intraepithelial spread
With Sebaceous Carcinomas of the eyelid, the nuclei are more atypical than a BCC. What stain do you need and what attribute is detectable in the cytoplasm?
Oil red O stain
– Vacuolization of the cytoplasm
Where do Sebaceous Carcinomas of the eyelid often spread?
Regional lymph nodes
= Parotid and Submandibular nodes
What cell type is very abundant in the Conjunctiva?
Goblet cells
What infection can produce significant scarring of the Conjunctiva?
Chlamydia Trachomatis
Dry eye affects the conjunctiva. Describe how it arises.
- Conjunctival scarring decreases the number of Goblet cells
- Decreased Goblet cells = Decreased mucin
- Decreased mucin = Decreased adherence of aqueous tear film
What are 2 unique lesions that can affect the conjunctiva after sun damage?
Pinguecula
Pterygium
How do Pinguecula and Pterygium lesions look on the Conjunctiva?
Small, yellowish submucosal elevations
On the conjunctiva, where do Pingueculas usually arise?
At the limbus
What type of growth differentiates a Pterygium from a Pinguecula on the conjunctiva?
Pterygium encroaches onto the cornea in a wing-like fashion
A small, yellowish submucosal elevation of the conjunctiva that is encroaching onto the cornea in a wing-like fashion is likely a?
Pterygium
Due to Pterygiums encroaching onto the cornea, what symptom will be present with them that is not present with Pingueculas?
Visual impairment
What are 2 common neoplasms that affect the conjunctiva?
Squamous Cell Carcinoma – HPV 16/18
Melanoma
Melanoma on the Conjunctiva usually involves what mutations?
BRAF v600 mutations
Nevi (moles) can affect the Conjunctiva. Describe Junctional, Compound, and Intradermal Nevi.
Junctional - epidermal melanocyte nests along dermoepidermal junction
Compound - melanocyte nests in dermis and epidermis
Intradermal - melanocyte nests only in dermis
What can compound nevi of the conjunctiva contain?
Cysts
Immature superficial nevi grow how? Mature deeper nevi grow how?
Immature superficial = nests
Mature deeper = cords
What are the layers of the Cornea?
- Bowman layer
- Stroma
- Descemet Membrane
What is unique about the stroma layer of the cornea?
NO blood vessels/lymphatics
– Transparent but hard to repair
If copper deposits occur in the eye with Wilson’s disease, where do they get deposited?
Descemet membrane of the cornea
With a corneal transplant, what is there a lack of and why?
Lack of rejection!
– Stroma lacks blood vessels
If exudate leaks from the iris/ciliary body into the anterior chamber, what is that called? – cornea affected
Hypopyon
Acanthamoeba can affect the Cornea. What symptom will occur and in what patients?
Permanent visual impairment
= contact lens wearers with poor hygiene of lenses and hands
What infection may occur in the cornea of contact lens wearers with bad hygiene?
Acanthamoeba
Herpes Simplex Virus Keratitis can also affect the Cornea. What type of pattern is the opacification and swelling of the cornea? If chronic, what reaction will take place and where?
Dendrite-linear pattern
– Granulomatous reaction at the Descemet’s membrane
What causes corneal degenerations?
Inflammation
What are 3 types of Corneal Degenerations?
- Calcific band keratopathy
- Actinic band keratopathy
- Keratoconus
Calcific Band Keratopathy of the Cornea
(Corneal degeneration)
- Calcium is deposited in Bowman layer of the cornea
Actinic Band Keratopathy of the Cornea
(Corneal degeneration)
- Collagen becomes yellow due to UV light exposure
Keratoconus of the Cornea
(Corneal degeneration)
- Bilateral central thinning and anterior protrusion
Keratoconus results in what type of vision and what is the treatment?
Irregular astigmatism
– Rigid contact lenses is the treatment
Bilateral central thinning of the cornea with anterior protrusion
Keratoconus
Corneal degeneration
With Keratoconus, where are the breaks in the cornea?
Bowman layer
What causes Corneal Dystrophies and how do they occur?
Deposition of abnormal material
– FAMILIAL occurrence
What is a type of Corneal Dystrophy?
Fuchs Dystrophy
Fuchs Dystrophy of the Cornea
Descemet’s membrane is thickened with guttata (drop-like) material protruding into anterior chamber
Descemet’s membrane is thickened with drop-like material protruding into the anterior chamber of the eye
Fuchs Dystrophy (corneal)
