Ocular Pathology 1 Flashcards
Corneal Edema
Cornea is opaque — you can’t see into the eye
Cataracts
Lens is opaque – should be able to see Iris around the lens
What can cause Corneal Opacity?
- Corneal Edema
- Corneal Deposits
What can cause Corneal Edema?
- Injury to epithelium (ulceration)
- Injury to endothelium
- Keratitis
What are 3 examples of Injury to endothelium in Corneal Edema?
- Corneal Endothelial Dystrophy
- Increased IOP (Glaucoma)
- Immune mediated
What is it called when young budding capillaries are present in cornea?
Keratitis
What can you use to detect a ulceration of the corneal epithelium?
Fluorescine dye
How does the Fluorescine dye work?
It sticks to the STROMA
NOT the epithelium
Where is the edema coming from in a ulcerated cornea?
Tear Film (outerworld)
What is neovascularization?
Keratitis - leaky capillaries
What is the condition called when you have tiny blood vessel growing into the cornea from the limbus?
Keratitis / Neovascularization
How do p get Corneal Endothelial Dystrophies?
- Inherited; Breed predilections
- Old age change
T/F:
Corneal Endothelial Dystrophies endothelial degeneration is of unknown cause
TRUE
________: Bilaterally symmetrical foci of opacity which progress to diffuse opacity
Corneal Endothelial Dystrophies
Puppy that survived the acute phase of infectious__________________; immune complex deposition in corneal endothelium. Blue Eye…
Canine Hepatitis (CAV-1 infection)
Canine Adenovirus is the classic cause of
“Blue Eye”
Corneal Endothelial Dystrophy
What is the most common DZz of the lens?
Cataract
Swelling/Degeneration of lenticular fibers results in
Opacity
What does the lends do in response to injury?
Fibers swell/take on water > fiber fragmentation & disintegration
Hyperplasia & Fibrous Metaplasia of lens epithelium
When do you categorize a cataract as “Hypermature”?
When it gets to be so wrinkled and white – loss of lenticular fibers n the inside so the lens is shrinking and the capsule is wrinkling up on itself and mineralization
Which of the following would NOT result in a cataract?
A.Radiation
B.Increased IOP (Glaucoma)
C.Endophthalmitis
D.Hereditary defect in lenticular metabolism
E.Diabetes mellitus (high glucose in aqueous)
F.Trauma
G.None of the above
G- None of the above
How do you examine the back of eye? (Tepedum, optic nerve, vessles that supply the retina)
Fundic exam
-Decreased vascularity
-Optic Disc Atrophy
-Changes in Tapetal Reflection
All of these are indications of…
Retinal Degeneration (& Atrophy)
If you’re loosing retinal tissue, will the tapetum become more reflective or less reflective?
MORE REFLECTIVE, because the retina is usually covering. This is why the owner will see flashes more
What are causes of Retinal Degeneration & Atrophy?
- Old age
- Progressive Retinal Atrophy (PRAs)
- Sudden Aquired Retinal Degeneration
- Toxicity
- Metabolic Def- Taurine, Vit A
- Increased IOP
- Retinal Detachment
What are the 2 Inherited metabolic defects of photoreceptor cells that cause retinal degeneration & atrophy?
Progressive Retinal Atrophy
and
Sudden Acquired Retinal Degeneration
What can be the result of Enrofloxacin toxicity?
Aquired blindness
Loss of photoreceptors and outer nuclear & plexiform layers
Mdx: Retinal atrophy and degeneration
What are indicators to remove the eye for histopathology?
- Painful eye
- Something in eye that is going to affect animal as a whole or /other eye
What are the 2 main mechanisms as to why p can have detached retina?
Cells accumulating under retina
(WBC,RBC, Neoplasia cells)
OR
Traction
Inflammation in back of eye. Usually between cilliary bodies.
Hypertension p and p who are a HBC are at risk for…
Retinal detachment (hemorrhage)
Whenever you have retinal detachment, either exudative or tractional, what is it usually due to?
INFLAMMATION!
Hemorrhage and Neoplasia are the exceptions
What is it called when there are fibrious adhesions between ciliary bodies?
Cyclitic Membrane
What’s the consequence of retinal detachment?
Retinal Degeneration and Atrophy because they don’t have nutrients from neighboring cells
Retinal pigmented epithelium are important for…
nourishing the photoreceptor cells. If retina separates, degen and atrophy of retina
Golden retriever - glaucoma
pic
How does glaucoma happen?
Increased IOP, occurs when theres too much aqueous humor. ITS BAD because 2ndary lesions will occur.
What lesions might a glaucomic eye have?
- Opacity
- Retinal degen and atrophy
- Cataracts
How is aqueous humor produced?
By the ciliary body and flows through posterior chamber through the pupil into the anterior chamber to the filtration angle where the iris meets the cornea
When there is a malformation of the filtration angle, it is congenital. What is this called?
Goniodysgenesis
Goniodysgenesis is a detectable malformation of the trabecular meshwork that will result in…
Primary Gluacoma
T/F:
In dogs, Goniodysgenesis is inherited and common
TRUE
How does spontaneous lens luxation lead to glaucoma?
It will block the filtration angle and lead to glaucoma if the obstruction isn’t removed.
Primary Glaucoma is caused by…
a congenital malformation/developmental abnormality of the filtration angle – not formed properly
Primary Glaucoma is common inherited condtion in the…
Dog
Matilda the cat is an example of primary or secondary Glaucoma?
Secondary— way more common than primary in domestic animals
Anything that obstructs the pupil or trabecular meshwork can result in….
Secondary Glaucoma
Give examples of causes of Secondary Glaucoma:
Exudate, Lens Luxation, Posterior Synechia, Peripheral Anterior Synechia, or Compression of the filtration angle
The Iris can adhere to the lens or it can adhere to the cornea. What do we call it when it adheres to the lens? Adheres to the cornea?
Lens- Posterior Synechia
Cornea- Anterior Synechia
either can result in Glaucoma
What does the term Peripheral Anterior Synechia mean?
More severe Anterior Synechia
What does Buphthalmos mean?
Enlargement of the globe
With corneal edema- if the expansion is super quick the desimis membrane will bust apart at the seams. As a result we would see..
Striae where the desimis membrane is coming apart
Pressure atrophy on the retina. When this pressure is so severe and theres pressure on the optic nerve head, what can be a result of this?
Optic Disc Cupping
** we can see histologically OR in part of a Fundic Exam
Is the retina is atrophic, we can get secondary…
Optic nerve atrophy
Glaucoma can result in a…
Cataract
T/F
Lens luxation can cause glaucoma, but it can also be a result of glaucoma
True, because if the globe is expanding, the zonule fibers that hold the lens in place can rupture and the lens won’t move around
If the blood supply to the iris is impeded in a case of Glaucoma, what can be the result?
Iris Atrophy
What is it called when a iris looks “Moth Eaten”
Iris Atrophy
Ayfakent Crescent (lack of lens)
Lens is no longer in a central position, it has migrated down
What is the term used for “Inflammation of the Eyelid”
Blepharitis
What is “Chalazion”?
Granulomatous inflammation directed against meibomian gland
What is “Stye”?
Common name for a bacterial infection of hair follicle or meilbomian gland (usually Staph aureus)
What are Meibomian Glands?
Modified sebaceous glands that are at the margins of the eye lids – they are important for providing an oil component of the tear film
What does the term “Chemosis” mean?
Severe conjunctival edema
Hyperemia Swelling/Edema Discharge Chemosis Pigmentation
Are all gross features of…
Conjunctivitis
T/F
Hyperemia alone does not necessarily indicate conjunctivitis
TRUE
Do primary infections usually cause conjunctivitis?
No, primary pathogens causing conjunctivitis is usually rare. But there are exceptions
What is the exception with Primary causes of conjunctivitis?
CATS!
Herpesvirus 1
Chlamydophilia felis
Mycoplasma felis – can normally be there OR secondary pathogen
If we have a severe conjunctivitis case clinically, will we biopsy?
NOPE! Bc the cause will not be histopathological evident. All the pathologist will be able to say is its a chronic lymphocytic conjunctivitis no matter what agent started it.
What will present as a nodular mass between the junction of the cornea and sclera?
Nodular Granulomatous Episcleritis
What are some DDX for this nodular mass on the eye?
Neoplasia
Nodular Granulomatous Episcleritis
Abscess
Histologically, what would Nodular Granulomatous Episcleritis look like?
Granulomatous keroconjunctivitis
What could cause this granulomatous inflammation?
Bacteria or fungi OR is it Collie?!
What’s an immune mediated condition of collies? Often Bilateral!
Nodular Granulomatous Episcleritis
Edema Epithelial Regeneration Neutrophil Mediacted Stromal lysis Neovasularization Stromal Fibrosis
Coreal response to injury
If the corneal epithelial surface isn’t all eroded all the way through, what speed will it regenerate?
Very rapidly since the basement membrane is intact
If the corneal epithelial is eroded all the way through/deep defect – ULCER, what speed will it regenerate?
There has to be repair of the stroma before the cells can fill the gap
If there is chronic/persistent injury _______ _____ may occur.
Cutaneous Metaplasia of the cornea - epithelium transform– like skin lacking hair follicle. it will no longer be transparent
What bacteria love to be opportunistic in corneal ulcers?
Pesudomonas aeuginosa
What primary pathogen will cause keratitis?
Moraxella bovis – causing Infectious Keratoconjunctivitis of cattle
