Ocular Flashcards
What is the circulatory disorder present in this puppy?
Corneal edema
What are the three general causes of corneal opacity?
Injury to epithelium
Injury to endothelium
Keratitis (Conreal inflammation)
What is the consequence of injury to corneal epithelium?
Corneal ulceration
What the the possible causes of injury to corneal endothelium?
Corneal enothelial dystrophy
Increased IOP (Glaucoma)
Immune-mediated
What is the primary cause of keratitis?
Neovascularization with leaky vessels
What is the diagnosis?
How did you come to that conclusion?
Corneal ulceration
Uptake of the fluorescent stain
What is the diagnosis?
Kertitis - note the neovascularization from the limbus visible grossly over the iris
When you see corneal opacity that is due to endothelial injury, would you expect to see this unilaterally or bilaterally?
Bilateral in most cases
What is the primary differential in a young puppy with bilateral diffuse corneal edema?
What is the common name for this finding?
Previous acute infection with infectious canine hepatitis (Canine Adenovirus 1)
Blue eye
What is hyphema?
What is the source?
What are your two primary rule outs for why it is present?
Blood in the anterior chamber of the eye
Typically the uvea or the retina
Primary vascular lesion vs. disorder of hemostasis
What is a serious potential consequence of hyphema?
Can block ocular drainage causing increased IOP
What is seen in the photo below?
Retinal hypertensive vasculopathy
A 6 year old dog comes into your clinic and this is what you see. They are painful, epiphora is present.
What is morphologically wrong?
What is your primary differential diagnosis?
Cataracts
Glaucoma (increased IOP)
What is the cause of PRIMARY glaucoma?
What species is this common in?
Goniodysgenesis - a detectable malformation of the trabecular meshwork
Dogs
What the hell does this pink smash show us?
Goniodysgenesis
Which is more common, primary or secondary glaucoma?
Secondary
What is the cause of secondary glaucoma?
Give some examples.
Anything that obstructs the pupil or trabecular meshwork
Exudate (Endophthalmitis)
Lens luxation
Posterior synechia
Peripheral anterious synechia
Compression of the filtration angle
What are some consequences of glaucoma?
Buphthalmos (Bulging eyes)
Retinal degenration & atrophy
Optic disc cupping
Optic nerve atrophy (loss of ganglion cells)
Cataract
Lens luxation
Iris atrophy
What is the most common disease of the lens?
What is its pathologic process?
Cataract
Swelling/Degeneration of lenticular fibers
What is the MDx?
What is the cause?
Lenticular (nuclear) sclerosis
Senile change
What are the possible causes of retinal degeneration & atrophy?
Senile change
Inherited metabolic defect of photoreceptor cells (Progressive retinal atrophy / SARD)
Toxicity
Metabolic deficiencies - taurine, vit. A
Increased IOP
Retinal detachment
What are the causes of retinal detachment?
Which is the most common?
Choroiditis, retinitis
Hemorrhage
Neoplasm
Trauma
Most common - inflammation (choroiditis, retinitis)
When the retina detaches, which two layers are separated?
The neural and pigmented layers
What is the primary consequence of retinal detachment?
Retinal degeneration and atrophy
What are the gross features of conjuctivitis?
Hyperemia
Swelling/edema
Discharge
Chemosis
Pigmentation
What is chemosis?
Severe conjunctival edema
True or false - Hyperemia alone is enough to indicate conjunctivitis.
False
MDx?
Suppurative conjunctivitis
What are the three primary pathogenic causes of conjunctivitis in cats?
Herpesvirus (FHV-1)
Chlamydophilia felis
Mycoplasma felis - normal resident or secondary pathogen
How does the cornea respond to injury? (5 ways)
Edema
Epithelial regeneration
Neutrophil mediated stromal lysis
Neovascularization
Stromal fibrosis
If eroded, epithelial regeneration is very rapid. However, if ulcerated what must preceed epithelial regeneration?
Stromal repair
In the presence of chronic/persistent injury, what may occur in the cornea?
Cutaneous metaplasia
MDx?
Cutaneous metaplasia due to chronic corneal injury
What are some possible etiologies of keratitis?
Give some examples of each.
Trauma
Bacterial (Pseudomonas aeruginosa/Moraxella bovis)
Chlamydia/Mycoplasma
Viruses (IBR, MCF, FHV-1)
Fungi (Aspergillosis, mucormycosis)
Drying and dessication (Keratoconjunctivitis sicca)
Idiopathic
What does keratomalacia mean?
What is it?
What is the cause?
Melting ulcer
Necrosis of corneal epithelium and stroma
Usually rapdily progressing bacterial or fungal infection
MDx?
What is that exactly?
Next step?
Descemetocele
Melting ulcer has melted down to the edothelium and is at risk for rupture of the globe
Emergency referral to specialist.
What is phthisis bulbi?
End stage eye - shrunken/atrophic, scarred/fibrotic eye.
What is corneal sequestrum and what is it frequently confused with?
Happens in cats mostly. Localized area of necrosis of the epithelium and anterior stroma from severe corneal injury.
Confused with Corneal pigmentation.
What is the pathogenesis of KCS?
Immune-mediated (most commonly) or other injury to lacrimal glands –> decreased tears and/or change in composition of tears –> drying out of cornea/conjunctiva –> chronic irritation
MDx?
Hypopion/Anterior uveitis
What is anterior uveitis vs. posterior uveitis?
Anterior - iridis (iris) and cyclitis (ciliary body)
Posterior - choroiditis (choroid)
What is endophthalmitis?
Inflammation of uvea, retina, and vitreous
What is Panophthalmitis?
Endophthalmitis PLUS corneal and scleral inflammation
What are the 3 general causes of uveitis?
Give some examples
Hypersensitivity - Feline idiopathic lymphoplasmacytic uveitis; Equine recurrent uveitis
Infectious - FIP; systemic mycoses; perforation corneal ulcers; penetrating injuries (secondary infections)
Lens induced - releasing proteins causing inflammation
MDx?
Keratic precipitates and rubeosis iridis
MDx?
Corneal ulcer, corneal edema, and hypopyon
MDx
Posterior synechia
(And a cataract)
What is the consequence of a Pre-iridal fibrovascular membrane?
PIFM –> Closed drainage –> Glaucoma
What are some consequences of uveitis? (there is a lot)
Synechia (fibrous adhesions)
PIFM (Pre-iridal fibrovascular membrane)
Cataracts - inadequate aqueous flow or posterior synechia
Lens luxation
Glaucoma
Retinal detachment
Phthisis bulbi
WTF is going on here?
Cataract with dyscoria
Dyscoria indicated by scalloped edge which is the iris is stick to the lens
What are other names for Equine recurrent uveitis?
Periodic ophthalmia
MOON BLINDNESS
Iridocyclitis
What is the most common cause of blindness in equids?
What is it caused by?
Moon Blindness or equine recurrent uveitis
Caused by hypersensitivity to previous systemic infection, particularly Leptospira interrogans
What is lens-induced uveitis?
What are the two types?
Which is worse?
Inflammatory response to lens protein
Phacolytic - leakage of lens proteins from hypermature cataract
Phacoclastic - rupture of the lens
Phacoclastic is more severe
What do you see here?
What is it indicative of?
Rubeosis
Anterior uveitis
What are some major causes of retinitis?
Neurotropic viral infections (rabies, distemper)
Visceral larval migrans (Toxocara canis, Baylisascaris)
What is a major cause of synophthalmos or cyclopia in lambs?
Veratrum californicum ingestion on day 14 of gestation
What are three major causes of developmental anomalies?
Genetic defect
In utero infection - BVD, Bluetongue, border disease, akabane, panleukopenia, classical swine fever
In utero exposure to teratogens
The fuck?
Lamb with inherited microphthamlia
Dude, seriously, what the actual fuck is this?
How bad is it?
Corneal dermoid
Iz bad, requires surgical intervention
What’s wrong with this?
Posterior lens luxation
What’s this?
Anterior lens luxation
How can lens luxation occur?
Trauma, inflammation (severe uveitis), glaucoma
What is the pupillary membrane?
Vascular tunic which supplies the lens during early development, usually regresses with age
What is this?
(No, not Eye of the Jew)
Persistent pupillary membrane
What is this developmental anomaly?
Iris hypoplasia
What is this weird shit?
Iris coloboma
What is shown in the image below?
How can this happen?
Retinal dysplasia
A wide array of retinal injury to the embryonic eye (BVD, bluetongue, canine parvo), or as an inherited condition
What cell type is proliferating?
Diagnosis?
Melanocytes
Iris melanoma
What is the most common intra-ocular neoplasm?
Who does it happen most commonly in?
Benign or malignant?
How can you tell this is it?
Diffuse Iris melanoma
Most commonly in cats (esp. with yellow eyes)
Most are malignant (benign in dogs)
Raised lesions with a velvet looking surface on the iris, +/- distortion of the iris/pupil
What are the most important prognostic indicators for melanocytic neoplasms?
Species and location
In regards to canine melanomas of/around the eye, which are benign and which are malignant?
Haired skin of eyelid - Benign
Conjunctiva - malignant
Ciliary (iridociliary) adenoma/carcinoma:
Who is it in?
Benign/Malignant?
Secondary concerns?
In dogs more than cats
Most are benign -behave benign even if histologically malignant
Secondary glaucoma, hyphema, retinal detachment
Intraocular sarcoma-
Who gets it?
Benign/Malignant?
Pathogenesis?
Unique to cats (rare)
Malignant.
Arises after ocular trauma, probably derived from lenticular epithelium –> wide invasion throughout eye, including down optic nerve
Can have distance metastasis following enucleation
What is the most common metastasis involving the eye, especially in cats?
What’s it look like?
Uveal lymphoma
Thickening/pallor of uvea; difficult to differentiate from uveitis
What’s up with that right eye?
This is a chicken, what’s your diagnosis?
Ocular lymphoma
Marek’s disease (gray eye)
What’s dis?
Meibomian (sebaceous) adenoma
Diagnosis?
Corneal squamous cell carcinoma
Dx?
Breed specific?
Associated with?
What’s another possible Ddx?
Corneal lipidosis
No, but breed predilections
Associated with hyperlipidemia
Ddx - early corneal (endothelial) dystrophy
What are Florida Spots?
Who gets them?
Tropical Keratopathy
Cats
How does corneal pigmentation occur?
Derived from entrapped uvea
Repsponse to injury
