Chapter 29: The Eye Flashcards
Many blinding conditions that result from pathologic angiogenesis (i.e., corneal neovascularization and diabetic retinopathy) can be sucessfull treated using what?
VEGF antagonists
Proptosis of the eye is representative of which kind of lesions within the orbit?
Space-occupying lesions
Enlargement of the lacrimal gland from inflammation or neoplasm produces proptosis which displaces the eye in which direction?
Inferiorly and medially
What are the 2 most common primary tumors of the optic nerve and what type of proptosis do they produce?
- Gliomas (especially pilocytic astrocytomas) and Meningiomas
- Axial proptosis (eye bulges straight forward)
Axial proptosis is an important clinical manifestation of which thyroid disorder?
- Graves disease —> Exophthalmos
- Enargement of the extra-ocular muscles w/ increased glycosaminoglycans
Uncontrolled sinus infections may spread to the orbit as an acute bacterial infection, this occurs most commonly in which patients?
Immunosuppressed or DKA (mucormycosis!)
________-related disease should be excluded before declaring an orbital inflammation to be idiopathic
IgG4-related disease
The presence of necrosis and degenerating collagen along with vasculitis in orbital inflammation should raise the suspicion of which disease?
Wegener granulomatosis
Idiopathic orbital inflammation is characterized histologically by?
Chronic inflammation and variable degrees of fibrosis
Which immune cells are typically part of the inflammatory infiltrate associted with idiopathic orbital inflammation?
Lymphocytes and plasma cells; occasionally eosinophils
What is the origin of the most frequently encountered primary neoplasms of the orbit?
Vascular in origin (capillary hemangioma of infancy and early adulthood, lymphangioma (children), and cavernous hemangioma (adults))
Which 4 orbital masses are encapsulated?
1) Cavernous hemangioma
2) Pleomorphic adenoma of the lacrimal gland
3) Dermoid cyst
4) Neurilemmoma
Drainage system of the sebaceous gland obstructed at the eyelid margin is called?
Blepharitis
What is the most common malignancy of the eyelid?
Basal cell carcinoma
Basal cell carcinoma tends to more commonly affect which 2 areas of the eyelid?
- Lower eyelid
- Medial canthus
When lipid extravasates into surrounding tissue and provokes a granulomatous response producing a lipogranuloma in the eyelid, this is known as?
Chalazion
Sebaceous carcinoma of the eyelid has a predilection for ______ spread and tends to spread first to the _______ and _______ nodes
Sebaceous carcinoma of the eyelid has a predilection for intraepithelial spread and tends to spread first to the submandibular and parotid nodes
What are the morphological characteristics of a basal cell carcinoma of the eyelid?
- Pearly nodules, telangiectatic vessles, central ulcer (“rodent ulcer”), rolled edges
- Peripheral palisading
*Pearly w/ depressed central area
Sebaceous carcinoma of the eyelide is most commonly seen in which gender/age?
What ethnicity is at higher risk?
- Woman >40 yo
- Asians
_______ spread of sebaceous carcinomas may mimic Bowenoid actinic keratosis in the eyelid and carcinoma in situ in the conjunctiva
Pagetoid
What is the morphology of the neoplastic cell cytoplasms seen in sebaceous carcinoma of the eyelid?
“Foamy” cytoplasm
Which stain is considered the best for the diagnosis of sebaceous carcinomas of the eyelid?
Oil-Red-O staining of fresh-frozen tissue
Which tumor is seen in the eyes of AIDS patients and if present in the eyelid appears purple, but will appear bright red if in the conjunctiva?
Kaposi Sarcoma
Granulomas associated with systemic sarcoidosis may be detected in which part of the conjunctiva?
Conjunctival fornix
Primary lymphoma of the conjunctiva is most likely to develop in what part?
Fornix
Infection by which organism may produce significant conjunctival scarring?
Chlamydia trachomatis (trachoma)
Dry eyes (xeropthalmia) results from a deficiency in the aqueous component of the tear film generated by?
Accessory lacrimal glands embedded within the eyelid and fornix
A reduction in the number of which cells associated with the conjunctiva leads to a decrease in surface mucin, which is essential for the adherence of the aqueous components of tears to the corneal epithelium?
Goblet Cells
Submucosal growth of fibrovascular CT that migrates onto the cornea in a winglike fashion is known as?
Pterygium
A small, yellowish submucosal elevation appearing astride the limbus, but not invading the cornea, is known as what?
Pinguecula
Pterygium and Pinguecula are a result of what?
Sun exposure (actinic damage)
Squamous papilloma and conjunctival intraepithelial neoplasia may be associated with the presence of which virus?
HPV types 16 and 18
What is the significance of Mucoepidermoid Carcinomas of the conjunctiva?
Follow an aggressive course
Squamous neoplasms and melanocytic neoplasms and their precursors tend to develop at which part of the conjunctiva?
Limbus
Pigmented lesions (nevi) of the conjunctiva most likely represent?
Melanomas or melanoma precursors
Conjunctival melanomas typically develop through a phase of intraepithelial growth termed?
Primary acquired melanosis with atypia
What is the most common primary intraocular tumor in adults?
Uveal melanoma
Where s the first evidence of metastasis of uveal melanomas typically seen due to its almost exclusively hematogenous spread?
Liver
What are the 2 oncogenes associated with Uveal Melanomas?
GNAQ and GNA11
Which conditions may give the sclera a “blue” appearance?
- Following episodes of scleritis may become thin, brown color turns blue from the Tyndall effect
- Thinned in eyes with high intraocular pressure; lesion known as staphyloma
- Osteogenesis imperfecta
- Due to heavily pigmented congenital nevus of underlying uvea, condition known as congenital melanosis oculi; accompanied by periocular cutaneous pigmentation is known as nevus of Ota
What makes up the major refractive surface of the eye?
Cornea and overlying tear film - not the lens
What is Myopia and why does it develop?
- Short-sightedness – can see near, trouble seeing far
- Images falls in front of the retina
- Eye is too long for its refractive power
What is Hyperopia and why does it develop?
- Far-sightedness – can see far, trouble seeing near
- Image falls behind the retina
- Eye that is too short for its refractive power
Which stain is used to highlight the basement membrane of the cornea?
PAS
Which features of the cornea contribute to high rates of success with corneal transplantation?
Lacks blood vessesl and lymphatics
Risk of corneal graft rejection increases with what?
What type of graft rejection is most common?
- Increases w/ stromal vascularization, inflammation and invasion
- Non-immunologic graft rejection = more common
Corneal vascularization may accompany what pathologies and how can it be treated?
- Corneal edema, inflammation, and scarring
- VEGF antagonists
The corneal endothelium is derived from which primitive cell lineage?
What does it rest on?
- Neural crest cells
- Corneal endothelium rests on its basement membrane, Descemet mebrane
What is the site of copper deposition in the Kayser-Fleischer ring of Wilson disease?
Descemet membrane (corneal basement membrane)
Infection with which bacteria may cause corneal ulceration (keratitis)?
- Staphylococcus aureus
- Streptococcus pneumoniae
- Pseudomonas aeruginosa
- Enterobacteriacea
Which viruses and protozoa can cause corneal ulceration (keratitis)?
- Herpes simplex and herpes zoster
- Acanthamoeba
Chronic herpes simplex keratitis is associated with what morphological finding in the cornea?
- Granulomatous reaction involving the Descemet membrane
- Infected cells may coalesce to form multinucleated giant cells
In keratitis, dissolution of the corneal stroma may be accelerated how?
Activation of collagenases within corneal epithelium and stromal fibroblasts (aka keratocytes)
What is the pattern of injury of corneal degenerations and are the familial?
- Can be unilateral and bilateral
- Typically nonfamilial
What is the pattern of injury of corneal dystrophies and are they familial?
- Typically bilateral
- Hereditary
What occurs in Calcific band keratopathy?
May complicate what condition?
- Deposition of calcium in the Bowman layer = Corneal degeneration
- May complicate chronic uveitis, especially in chronic juveline rheumatoid arthritis