Path 1 - Eye 1

drraythe's version from 2016-05-02 00:21

Eye dzs

Question Answer
Neuroectoderm does what? Ectoderm does what?Neuroectoderm: Paired invaginations which form optic vesicles → optical cup → Retina
Ectoderm: Lens placode invaginates → lens vesicle → Lens
Congenital inclusion cyst is?Entrapment of epith. cells in cornea
Trichiasis is?Rubbing of eyelashes against the eye surface
What is CYCLOPIA? What should you know about it?Single medial globe (day 14 veratrum alkaloids)
Whats is SYNOPHTHALMIAIncomplete separation or early fusion of globes
What is a COLOBOMA? How does this happen?GAP/NOTCH/FISSURE of the eye
Failure of fusion of OPTIC CUP (embryonic fissure), which leads to an outpouching of neuroectoderm (scleral ectasia)
WHAT IS COLLIE EYE ANOMALY (CEA)? WHO gets this?Anomaly of MESENCHYME where there is improper development of optic cup leading to an abnormal retina & choroid. It is Inherited (Collies & Shetland Sheepdogs)
***What are the malformations/lesions of COLLIE EYE ANOMALY? What are the sequale?Abnormal Choroid & Retina (bc optic cup didn't develop right) which leads to *Chorio-retinal dysplasia/hypoplasia & Ectasia of Optic Disc/Sclera
Sequale are retinal degeneration & detachment & intraocular hemorrhage
To remember this:
C - (collie) Chorio-retinal dysplasia/hypoplasia
E - (eye) Ectasia of Optic Disc & Sclera
A - (anomaly) Abnormal Choroid & Retina
PERSISTENT PUPILLARY MEMBRANE → what is going on here?Delayed or incomplete ATROPHY of Anterior Perilenticular Vascular Network leads to bloodless strands crossing pupil
May obstruct vision & lead to corneal opacity
BLEPHARITIS is?Inflammation of the eyelids
What is a HORDEOLUM? What are the sequale?STYE!!
SUPPURATIVE ADENITIS of various eye lid glands
Persistent inflammation → GRANULOMATOUS response (HORDE of PUS on your EYELID)(eyelid pimple)
What are the 2 types of Hordeolum? (What glands are associated?)(1) Internal Hordeolum, Meibomian gland
(2) External Hordeolum, Moll (apocrine) & Zeis (sebaceous)
2nd MOST COMMON TUMOR OF CANINE EYELID? Benign or malig?MELANOCYTOMA, universally benign
***What is a CONJUNCTIVAL DERMOID composed of? Sp diffs?SKIN elements (**HAIR & sweat glands) on the CONJUNCTIVA!
Common in dogs (St. Bernard/Dalmatian) & cattle (Hereford)-inherited
The diff is:
(DOGS) LATERAL canthus & lateral limbus (the border of the cornea & the sclera)
(CATTLE) medial canthus, eyelid, 3rd eyelid
What is a Pterygium?BENIGN raised wedge-shaped GROWTH of conjunctiva
AQUIRED INFECTIOUS DZS of the conjunctiva are most common in who?Cats & Cattle
What are 2 viral dzs which cz CONJUNCTIVITIS???BOTH ARE HERPES!!!
***BACTERIA which infect the conjunctiva?*IBK “pink eye” Moraxella bovis**
Mycoplasma felis/gatae
Chlamydia psittaci
Parasites which infect the conjunctiva?THELAZIASIS (cattle/horses)
Habronema (horses)
(Oestrus ovis (sheep) )
Necrotic scleritis HAS COLLAGENOLYSIS
NODULAR GRANULOMATOUS EPISCLERITIS (NGE) aka? Where does it occur? What is going on?Aka "Collie Granuloma”, “Ocular Nodular Fasciitis”, “Fibrous Histiocytoma
It occurs in the LAMINA PROPRIA (loose CT layer just under epi. in MMs)
In dogs specifically the lamina propria of the conjunctiva
It is a nodular accumulation of macrophages & there is NO COLLAGENOLYSIS
What is Necrotic Scleritis? Whats going on?Immune mediated dz & there IS COLLAGENOLYSIS
What is the order of animals where neoplasms are most to least common?CATTLE > horse > dogs & cats
Congenital dz → OCULAR DERMOID → common in what sp? What happened embryonically for this to occur? What are the 2 types?Common in DOGS. Failure of complete fetal ectoderm corneal “metaplasia” → portion of ectoderm remains as SKIN (Hair follicles & adnexal glands present)
LATERAL canthus/limbus = CONJUCTIVAL
What is KERATITIS? What is the pathogenesis of this lesion?Inflammation of the cornea
It goes EDEMA → leukocyte immigration → corneal stromal vascularization → fibrosis → epithelial metaplasia w/ pigmentation
What are 2 major etiological agents of ULCERATIVE keratitis?IBK-Moraxella (pink eye)
FELINE HERPES V 1 → branching tracts of necrosis “dendritic ulcers”
***How is it that the ULCER of ULCERATIVE KERATITIS forms?Proteases/collagenases liquefy corneal stroma (keratomalacia) → ULCER
What is Keratomalacia??Proteases/collagenases liquefy corneal stroma (MALACIA MEANS SOFTENING)
**"Melting ulcer" of the cornea is called?SUPPURATIVE KERATOMALACIA
(Sequale of Moraxella bovis infxn)
"Ring abscess" on the cornea form how?Neutrophils encircle liquefying focus (from the suppurative keratomalacia → remember thats bc of the enzymes & malacia means softening)
Whats a descemetocele or keratocele?? How does this happen? Looks like?There is ulceration & softening of tissues → Stromal liquefaction of Descemet’s membrane (some membrane under the cornea, idk) → ↑ intraocular pressure PUSHES the membrane OUTWARD → **descemetocele or keratocele**
You will see a TRANSPARENT CENTER to the ulcer
WHAT IS Anterior Staphyloma?When there is an ANTERIOR SYNECHIAE (iris adheres to the cornea) & it becomes PERMANANT
Whats a Corneal Fistula?Ulcer lined by epithelial cells
EQUINE KERATOMYCOSIS (mycotic keratitis) → czd by? What are the 2 TYPES?Opportunistic aspergillus infxn
2 syndromes:
(1) Superficial stromal opportunistic infxn by fungi → no inflammation
(2) Deep stromal infxn → intense suppurative keratomalacia → untreated → corneal perforation/ iris prolapse
What is the MOST COMMON NON-ULCERATIVE acquired corneal dz? What does it look like?Stromal/interstitial (not epithelial)
Diffuse blue/grey clouding of cornea
What czs non-ulcerative dz of cornea → Stromal/interstitial / SUPERFICIAL dz? Who gets these? What are the lesions?(1) CANINE PANNUS KERATITIS aka “Chronic Superficial Keratitis”, “Uberreiter’s syndrome”. Happens most often in GSD form PROLONGED UV LIGHT & you will see MARKED PIGMENTATION!!
(2) EOSINOPHILIC KERATITIS (cats > horses) Granular WHITE proliferative lesion on cornea
You see a cat or horse w/ a granular WHITE proliferative lesion on cornea...what is it?EOSINOPHILIC KERATITIS (a stromal/interstitial superficial nonulcerative dz of cornea, note the pink color)
You see a GSD w/ MARKED pigmentation on the cornea. What is it?CANINE PANNUS KERATITIS aka “chronic superficial keratitis”, “Uberreiter’s syndrome” (a stromal/interstitial superficial nonulcerative dz of cornea, which is czd by overexposure to UV light)
Dz of cornea → Non-ulcerative → deep. Which disorder is this? Aka? Common in who? What is a major CS?KCS - KERATOCONJUNCTIVITIS SICCA
Aka “Desiccating Keratitis, “Chronic Dacryoadenopathy”
Happens in DOGS, more common in TOY breeds
↓ Lacrimal secretions → xerophthalmia “dry eye” (could be from congenital lack of lacrimal secretion, senile atrophy, or destruction or denervation of lacrimal gland/accessory gland)
Xerophthalmia is?Dry eye
Whats the uvea?VASCULAR PART of eye:
Ciliary body
Iris hypoplasia happens in who?Horse (Thin, irregularly shaped, non-mobile iris)
**CHOROID HYPOPLASIA → what is this? When do you see this?Inadequate pigmentation of the retinal pigment epithelium & choroids
Developmental anomaly you see in **Collie Eye Anomaly
ANTERIOR UVEITIS AKA?IRIdocyclitis (posterior is choroiditis)
ANTERIOR UVEITIS (IRIdocyclitis) can happen from what 3 things?Toxic damage (1° cz)
Localization of hematogenous infxns
Extension from neighboring structures (deep corneal ulceration)
ANTERIOR UVEITIS (IRIdocyclitis) → LESIONS?Vascular changes: Hyperemia/congestion of iridal & ciliary vessels
***Keratitis punctata → WHAT IS THIS?Clumps of inflammatory cells to posterior of cornea (this is under "anterior uveitis")
Will see “Mutton-fat” keratic precipitates = White/yellow greasy precipitates of inflammatory cells (granulomatous response) adhere to corneal epithelium
**Aqueous flare → WHAT IS GOING ON HERE? What are the sequale?Exudate (inflammatory cells/fibrin) in aqueous
Which is altered formation of aqueous → ↓ intraocular pressure
**What is Hypopyon?Yellow/white/pink floccular sediment in the anterior chamber
***WHAT IS Hyphema??Blood in the anterior chamber
What are 3 major sequale of ANTERIOR UVEITITS?Fibrinous exudate over iris (CAN LEAD TO SYNECHIA)
Atrophy of iris may follow severe necrotizing inflammation & cataract
ANT = Adhesion of iris or cornea

POST = Adhesion of iris to lens
*Iris bombe IS WHAT?Complete posterior synechia (360°) Blocks papillary aqueous flow → ↑ posterior chamber pressure. The iris may then bow forward & also attach to the cornea
Whats going on in occlusio papillae?Fibrovascular membrane forms on iris face → pupillary block → pectinate lig. covered → neovasular glaucoma
What is Phthisis Bulbi?Hypotonic
Disorganized eye
(end stage of severe opthalmitis)
POSTERIOR UVEITIS is aka?Choroiditis (anterior is Iridocyclitis)
**What are the lesions youd see in Posterior Uveitis/Choroiditis?Marked exudation (choroid / vitreous)
Retinal degeneration/detachment
Atrophy/proliferation of choroidal pigment cells
Equine Recurrent Uveitis (ERU) is a type of what? Aka?Type of Posterior Uveitis (Choroiditis)
Periodic ophthalmia “moon blindness"
What is the most frequent histological pattern of posterior uveitis in cats?Feline Idiopathic Lymphonodular Uveitis
What is the most frequent histologic pattern of posterior uveitis in dogs?Canine Lymphocytic Uveitis
Posterior uveitis condition which is common in Akitas, Siberian huskies, Samoyeds? What is happening?Uveodermatologic Syndrome (immune-mediated)
T-lymphocyte mediated destruction of melanin-producing cells of the RPE & uvea
*Spontaneous lens rupture not associated w/ trauma happens in what 2 spp. for what 2 reasons?Rabbits (Encephalitozoon cuniculi)
Dogs w/ diabetic cataracts
What is the normal aqueous flow of the eye?Ciliary body → posterior chamber → pupil → anterior chamber → iridocorneal angle
Congenital glaucoma is a result of what?Abnormal development of ANTERIOR CHAMBER
1⁰ glaucoma → what czs this? WHO is this common in?Malformation of the filtration angle
British & American Cocker Spaniels
WHAT IS GONIODYSGENESIS?Detectible maldevelopment of the TRABECULAR MESHWORK (Incomplete remodeling of the solid mass of the anterior chamber of the mesenchyme that gives rise to the stroma of the cornea & anterior uvea)
Open-angle glaucoma happens in who? Whats going on?BEAGLES!
No 1° histologic lesion, No visible abnormality in the structure of the trabecular meshwork or other portions of the aqueous outflow pathway
2⁰ glaucoma → whats going on here??2° to OBSTRUCTION of aqueous flow thru pupil
- could be a papillary block or trabecular occlusion
What is BUPHTHALMOS? Why does this happen?Enlargement of the globe, thinning of sclera (SEQUALE of GLAUCOMA)