Ocular Path Flashcards
What are the two main causes of corneal opacity?
Corneal edema
Corneal deposits
What are causes of corneal edema?
Injury to epithelium (ulceration)
Injury to endothelium
- corneal endothelial dystrophy
- increased IOP (glaucoma)
- immune mediated
Keratitis- neovasculrization with leaky capillaries
How can you visualize a corneal ulcer?
Flourescein dye
What causes the “blue eye” seen in puppies infected with canine hepatitis ?
Diffuse corneal edema due to immune complex deposition
What do you call blood in the anterior chamber of the eye?
Hyphema
What is usually the source of hyphema?
Blood vessels in the uvea or retina
What is retinal hypertensive vasculopathy?
Protein deposits in the blood wall
-> hypertension see in cats
A dog in the clinic presents with corneal opacity..
You can see blood vessels within the sclera due to production of the eye. What is the probable cause of the corneal opacity?
Glaucoma
What is he cause of primary glaucoma ?
Goniodysgenesis-> detectable malformation of trabecular meshwork (blocking drainage angle)
What is secondary glaucoma?
Anything that obstructs the pupil or trabecular meshwork
- exudate (endophthalmitis)
- lens luxation
- posterior synechia
- peripheral anterior synechia
- compression of filtration angle
Retinal degeneration and atrophy, optic disc cupping, and optic nerve atrophy are all consequences of ____________
Glaucoma
What is a cataract?
Swelling/degeneration of lenticular fibers-> opacity
What is the response of the lens to injury?
Hydronic swelling of injured fibers -> fiber fragmentation and disintegration
Hyperplasia and fibrous metaplasia of lens epithelium
Posterior lens epithelial migration
What is the response of the lens to chronic injury?
Shrinking and wrinkling of lens capsule and mineralization
T/F: lenticular sclerosis can occur due to senile change
Yes..
Lens differentiate throughout life -> cataract common in old dog
What are indications of retinal degeneration and atrophy?
Decreased vascularity
Optic disc atrophy
Changes in tapetal reflection
What are causes of retinal degeneration and atrophy?
Senile change Inherited metabolic defect of photoreceptor cells Toxicity Metabolic deficiencies Increased IOP Retinal detachment
Histology shows lost photoreceptor and outer nuclear and plexiform layers of the retina
What is your MDx?
Retinal atrophy (and degeneration)
What are causes of retinal detachment?
Choroiditis, retinitis
Hemorrhage
Neoplasm
Trauma
What is retinal detachment? What will the the consequence of this?
Separation between neural and pigmented layers
Rentals degeneration and atrophy
What is your MDX?
On conjunctiva..
Hyperemia
Swelling/edema
Discharge
Chemosis
Conjunctivitis
What is chemosis?
Severe conjunctival edema
What are the causes of conjunctivitis ?
Primary pathogens are rate (except in cats)
What pathogens of cats cause conjunctivitis?
Herpesvirus
Chlamydophilia felis
Mycoplasma felis
For an eye that has..
conjunctivitis, purulent discharge, and corneal edema..
What is the most likely cause? A.glaucoma B. Corneal endothelial dystrophy C. Antigen-antibody complex disease D. Corneal ulceration
D. Corneal ulceration
What is the response of the cornea to injury?
Edema Epithelial regeneration Neutrophil mediated stromal lysis Neovascularization Stromal fibrosis
T/F: if the cornea is eroded, epithelial regeneration can occur rapidly
True
If the cornea is ulcerated, _______________ repair must proceed epithelial regeneration
Stromal
A chronically injured corneal may result in ____________ which is a combination of keratinization, epithelial hyperplasia, pigmentation, subepithelial fibrosis, and vacularization
Cutaneous metaplasia
What primary pathogen of cattle causes keratitis
Moraxella bovis (pink eye/ keratoconjunctivitis)
What are the possible etiologies of keratitis?
Trauma Bacteria Chlamydia/mycoplasma Virus Drying and desiccation Idiopathic
German shepherds get what type of idiopathic keratitis
Chronic superficial keratitis (Pannus)