neural ectoderm

surface ectoderm

neural crest cells

strands of tissue in front of the pupil

pupil looks obscure

+/- patent vessels

Signalment=Basenji, Collie

persistance of the vascular tissue from the optic n.

looks like strands of tissue behind the pupil

common

congenital bilateral chorioretinal hypoplasia

 +/- coloboma

diagnosis=tiny retinal vessels, can see sclera through the affect vessels

signalment=autosomal recessive in Collies

congenitally small eye (usually malformed)

Signalment=common in dogs

microphthalmia

phthisis bulbi

notch like defect in the optic n.

associated with vision problems

diagnosis=optic disk looks like it is out of focus from the rest of the retina

a piece of the eyelid is misplaced onto the superficial cornea

treatment: superficial keratectomy

eyelid is too large

may lead to lagopthalmos

predisposed to corneal ulceration

Signalment=brachycephalic breeds

treatment=eyelid tuck (narrows the size of the eyelid opening)

shallow orbit

Signalment=brachycephalic breeds

cilia/eyelid are growing from the meibomian gland

the hair is directed toward the eye

leads to corneal ulceration/conjunctival irritation

Signalment=85% of american cocker spaniels

treatment=use cryosurgical probe to follicle

inversion of the lid margin/periocular skin

leads of corneal ulceration/conjunctival irritiation

signalment=breeds with excessive skin

treatment=resect the eyelid skin adjacent to the eyelid margin

this is common in newborn sheep and horses

due to high water content in the skin

suppurative (bacterial) inflammation of the eyelid?

diagnosis=looks like white micro-abscesses in the eyelid

treat with topical antibiotics

granulomatous inflammatory nodule from retained meibomian gland secretions?

treat with surgical debridment

staph

poxvirus

dermatophytes

Demodex

Habronema

immune mediated allergic reaction

meibomian gland adenoma

benign melanoma

papilloma

malignant

locally invasive

squamous cell carcinoma

white cats are most at risk

squamous cell carcinoma

(malignant, locally invasive)

sarcoid

(common, variable malignancy, oncogenic virus transmitted by face flies)

squamous cell carcinoma

(malignant, locally invasive)

mucous membranes

goblet cells

lympoid follicles

conjunctival hyperemia

engorgement of the bulbar conjunctival vessels, moves with a Q tip, superficial

scleral hyperemia

engorgement of scleral vessels, does not move with a Q-tip, deep

serous

mucoid

purulent

FHV-1*

chlamydia spp

mycoplasma spp

What is the most common conjunctival neoplasia in horses, cattle, and cats?

what are some of the predisposing factors?

squamous cell carcinoma

predisposing factors are UV-light

angiosarcoma

lymphoma

hemangioma

hemangiosarcoma

localized or diffuse primary scleral connective tissue inflammation

treatment=steroids

benign and slow growing

the more progressed forms can invade the corneal and iridocorneal angle

congenital laxity of the connective tissue anchoring the third eyelid

the eyelid flips out and is inflammed?

treatment is eyelid repositioning

prolapse of the third eyelid

"cherry eye"

squamous cell carcinoma*

lymphoma

fibrosarcoma

lacrimal/nasolacrimal opening doesn't open all the way

signalment=certain small breed dogs are predisposed

nasolacrimal duct inflammation

caused by a foreign body or bacterial conjunctivitis

causes euphoria and purulent discharge

flushes out when the duct is canalized

immune mediated suppurative or mononuclear inflammation of the lacrical gland

chronically it can lead to keratorconjunctivitis sicca

dacryoadenitis in dogs in commonly due to what?

cats?

rats?

dogs-bilateral and immune mediated

cats-FHV-1, usually bilateral

rodents-due to coronavirus

loss of transparency

corneal metaplasia

ulceration

edema

vascularization

inflammatory cell infiltrate

pigmentation

fibrosis

metabolic infiltrate

whitish-blue diffuse opacity that obscures the iris

aqueous humor accumulation in the cornea

superficial

from the conjunctival vessels

can see the vessels crossing the limbus

associated with superficial ulcers and dry eye

deep

from sclearal vessels

can not see vessels crossing the limbus

associated with deep corneal disease or uveitis

flat

homegenous

dense

lipid of calcium

(most likely lipid)

conjunctival vascular injection

miosis and ciliary body spasm

this is a true reflex to corneal injury

the iris contracts

the ciliarly muslces constrict (causes pain)

the is a reflex response to corneal injury

releases inflammatory mediators and cytokines

associated with inflammation

-epithelial wound healing

1 mm/day regeneration

sliding of cells

-stromal wound healing

slow, incomplete, new collagen production, generally not transparent

predisposed to secondary bacterial infection

1. can be secondary to any underlying condition (chronic irritation, altered lipid/Ca metabolism)

2. dystrophy (hereditary stromal lipid deposits caused by a defect in lipid metabolism in the cornea)

3. can be secondary to hyperlipidemia

note: dystrophy is usually centrally located and hyperlipidemia is usually peripherally located

hereditary stromal lipid deposits

caused by a defect in lipid metabolism in the cornea

usually centrally located

age related decline in endothelial cell density

clinical signs include progressive corneal edema, and vision loss

signalment=older dogs, Bostons, Chihuahuas, Dachshunds

treatment=corneal transplant

caused by excessive UV damage to the cornea, which leads to immune mediated vascularization and pigmentation of the cornea

type of non-ulcerative keratitis

common at high altitides and close to equator

there is the presence of lymphocytes and plasma cells in the lesion (follicle formation and infiltration)

type of non-ulcerative keratitis

degeneration and black discoloration of the center of the cornea

forms secondary to FHV-keratitis (pigmented porphyrins in the tear film attach to the dead cornea)

Signalment=brachycephalic cats

treatment=keratectomy

type of non-ulcerative keratitis

immune mediated

types of cells found are lymphocytes, plasma cells, and eosinophils

treatment=topical corticosteroids

eosinophilic keratitis

inhibits wound healing

inhibits the immune response

primary trauma/infection or dessication

secondary microbial infection

progressive stromal loss

epithelial loss

stromal loss

descemetocele

corneal perforation

the iris and fibrin move forward to plug a wound in the cornea

formation of anterior synechia

persistance of underlying disease

microbial infection

refractory/indolent epithelial ulcer

epithelial non-adherence to the basement membrane

can see a rim of nonadheredt epithelium around the ulcer

common in older dogs (Boxers) and horses

what causes corneal ulcearation in goats?

(keratoconjunctivitis AKA pink eye)

degernate strands of the iris

scalloped pupillary margins

patients have reduced pupillary light reflex

signalment=older dogs

ddx=neuro problem

degeneration of the epithelial layer on the back of the iris

iris breaks free and floats around in the anterior chamber

looks translucent, semi-opaque

usually asymptomatic

hyperpigmentation of the iris

looks like freckles

common in older cats

ddx=iris melanoma

iris melanosis if flat

iris melanoma is raised

pain

redness

swelling of the iris

loss of function

blood-ocular-barrier breakdown

spasm of iris and ciliary muscles

blepharospasm

photophobia

corneal edema

breakdown of the blood-ocular barrier

miosis (poor response to mydriatic agents)

hypotony

low intra ocular pressure

due to decreased aqueous humor production

aqueous flare

fibrin in the eye

hypopyon or keratic precipitates

hyphema

turbid aqueous

due to protein and cells

trauma (blunt or penetrating)

corneal or scleral injury

systemic microbial infection

immune mediated

more specifically:

canine adenovirus

lens induced uveitis

uveodermatologic syndrome

chronic idiopathic anterior uveitis

this is a type of lens induced uveitis

caused by penetrating trauma or laceration of the capsule that leads to severe uveitis

treatment=remove the lens

lesion involves pan-ueitis and dermal depigmentation

not life threatening but poor visual prognosis

signalment=artic circle breeds

treatment=systemic immunosuppresive drugs and topical anti-inflammatories

benign melanoma (98%)

ciliar body adenoma/adenocarcinoma

generally benign (mets are rare)

slow growing

can cause secondary glaucoma

malignant (60%metastaic to lungs and abdomen)

raised, progressively coalesing

worry about mets when IRC angle is involved

treatment=remove the eye to eliminate the pain

lymphoma

formation of cataract

displacement

any opacity in the lens

eventual fragmentation and liquification of the lens which leads to secondary uveitis

treatment=remove the lens OR replacement with prosthetic lens

ddx:lenticular (nuclear) sclerosis

remove the lens

or

replace it with prosthetic

incipitient

immature

mature

hypermature

stage of cataract development:

dark stop on tapetal reflection

no vision loss

stage in cataract development:

cataract takes up part of the lens

there is still some light on tapetal reflection

stage in cataract development:

lesion involves the entire lens

no tapetal reflection

total loss of vision

stage in cataract development:

liquification of the lens fibers and protein leaks out

eventual phacolytic uveitis

normal, progressive, age related process

compaction and hardening of the lens fibers

looks translucent but not opaque

there is light scattering but no obstruction of the tapetal reflection

may be confused with a cataract

genetic (alteration in lens metabolism)

trauma

diabetes mellitus

nutritional (puppies and kittens)

secondary to retinal degeneration

hyperglycemia

hexokinase pathway is overwhelmed

alternative pathway (aldose reductase)

end product is sorbitol

sorbitol is trapped in the lens

swelling of the lens

toxic byproducts are produced because of the retinal degeneration

these toxins interfere with lens metabolism

this is a result of lens displacement

looks like there is no lens behind the pupil area

can cause secondary glaucoma and uveitis

damage to the lens zonules

caused by:

(hereditary) wimpy zonules

secondary to uveitis in cats and horses

age related degeneration of the zonules

trauma (uncommon)

neural retina

optic nerve

nonpigmented ciliary epithelium

posterior chamber

pupil

anterior chamber

IRC angle

venous collecting vessels

systemic circulation

alterations in IRC angle that causes obstruction to outflow

bilateral progressive disease

#1 anterior uveitis (swelling of the uveal tissues in the angle or extensive posterior synechiae)

lens luxation (pupillary block or vitreous in the angle)

intumescent cataract

intraocular neoplasia

hyphema

corneal edema (damage to the corneal epithelium due to the high pressure)

conjunctival and scleral hyperemia

paralysis of the iris musculature (dilated and non-responsive pupil)

closed IRC angle

retinal atrophy (neuronal cell death)

optic nerve cupping or posterior bowing

buphthalmia (enlarged globe)

corneal scarring

sclera

choroid (vessels look like spokes on a wheel)

retinal pigmented epitheilum (deep to the retina)

sensory retina (translucent tissue)

tapetum

non tapetal fundus

retinal vessels

photoreceptors

rods/cones

bipolar cells

ganglion cells

appears depigmented in the nontapetal fundus due to the loss of retinal pigmented epithelium

the areas of this may be diffuse or focal

lesion is thinning or absence of the sensory retina

tapetal necrosis

RPE hyperpigmentation

this appears whitish in the nontapetal fundus

involves thickening to the sensory retina

acute inflammation (CAV-1, FIP, Toxo, mycotic)

retinal dysplasia (not progressive)

edema

neoplasia

multifocal vesicles

bilateral, symetrical, linear folds

rosettes on histopath

congenital in labs and cocker spaniels

ROSETTES ARE PROLIFERATION OF PHOTORECEPTORS

separation between the RPE and sensory retina due to accumulation of exudate*, blood, edema, or liquid vitreous

hyporeflective fundus

whitish discoloration of nontapetal fundus

folding of the retina

giant retinal tear

inflammation

hypertension

hyperviscosity

polycythemia

atrophy/degeneration of sensory retina

anemia

glaucoma

occulsive vascular disease

hypotension

vascular problem

inflammation

bleeding disorder

neoplasia

inflammation

neoplasia

dark discoloration

hyporeflectivity

atrophy and hypoplasia

collie eye anomaly

congenital hypoplasia

coloboma

cupping (due to glaucoma)

atrophy/loss of myelin

inflammation

excess myelin

edema

papilledema

coloboma

neoplasia

cellulitis or bacterial abscessation

could come from adjacent tissues like oral cavity, nasal cavity, sinuses

malignant

locally invasive

usually primary to orbital tissues