Special Senses (JKP, vol 1) Flashcards
This developmental anomaly of the eye in calves in most properly termed?
A. Cyclopia
B. Synophthalmos
B. synophthalmos
See how there is internal duplication of ocular structures - indicates fusion or incomplete separation of the optic vesicles rather than true cyclopia which is VERY RARE
True cyclopia is failure of division of the optic primordium as it grows from the telencephalon
Which is more prevalent cyclopia or synophthalmos?
Synophthalmos
Most single midline globes contain duplication of internal structures indicating it is a partial failure of optic vesicle separation or fusion at this stage
true cyclopia is VERY RARE because it results from failure of division of the optic primordium from the telencephalon.
Microphthalmia often occurs with ocular adnexa and muscle developmental anomalies?
TRUE or FALSE
FALSE!
They have different embryologic origins so multiple eye anomalies are seen together, but NOT usually with adnexa anomalies
Which is more common anophthalmos or microphthalmos?
micropthalmos
Think of how often we have seen or heard of this
Anopthalmos is EXCEEDINGly rare defined as true failure of formation of the primary optic vesicle (evagination of neuroectoderm from the forebrain)
Cystic eye and retinal nonattachment are caused by?
A. Anophthalmos
B. Fusion of the optic vesicles
C. Failure of formation of the primary optic vesicle
D. Persistence of the primary optic vesicle
D. cystic eyes are formed by persistence of the primary optic vesicle (single layer neuroectoderm) failure of invagination of the optic cup and apposition of the cranial ectoderm (skin side)
Collie eye anomaly is___?
A. posterior staphyloma also know as scleral ectasia defined as bulge in sclera caused by outpouching neuroectoderm
B. Autosomal recessive NHEJ1 gene intronic deletion
C. Bilateral optic nerve coloboma
D. Choroidal hypoplasia
E. All of the above
E. All of the above!
Collie eye anomaly – CEA common congenital inherited disease of smooth and rough Collies and related breeds. Defect is patchy to diffuse choroidal hypoplasia, autosomal recessive trait. NHEJ1 gene intronic deletion. Ophthalmoscopic findings retinal vessel tortuosity, focal to diffuse, choroidal and tapetal hypoplasia, optic nerve coloboma, retinal separation with intraocular hemorrhage, occ. Enophthalmos, microphthalmos, corneal stromal mineralization. Bilateral but not equal. Scleral ectasia aka posterior staphyloma- bulging of dysplastic neuroectoderm, continuous with retina, into the pit of the nerve head. Other retinal lesions include retinal folds, detachment. Caused by earliest lesion is defective differentiation of primitive RPE to form rosette-like structures near the optic disc
- An anomaly of mesenchyme (diffuse) during ocular development*
- JKP volume 1, special senses*
Bergmeister’s papilla in cattle (defined as a cone of glial tissue with a vascular core that extends from the optic disc a few mm into the vitreous) is an example of what ocular anomaly?
A. Goniodysgenesis
B. Persistent hyaloid artery
C. Hypoplasia of the iris
D. Scleral ectasia (posterior staphyloma)
B. persistent hyaloid artery in cattle is Bergmeister’s papilla
this results from failure of the posterior segment mesenchyme to atrophy! Think about the description provided, and a photomic could be given as an example for this question
goniodysgenesis is an anterior segment defect of the mesenchyme to atrophy at the filtration angle, pectinate (ligament) dysplasia
hypoplasia of the iris is an anterior chamber mesenchyme defect in formation, common in horses with conjunctival dermoids
scleral ectasia is a type of coloboma (failure of fusion, embryonic fissure) caused by outpouching of dysplastic neuroectoderm - continuous with retina and often bulges into the pit of the nerve head often seen in Collie eye anomaly since there is choroidal hypoplasia
JKP vol 1, special senses
Corneal dermoid (occurs in most any species) is best described as?
A. neoplasm
B. hyperplasia
C. choristoma
D. hamartoma
C. choristoma
The corneal (or conjunctiva) forms a focal tumor (not neoplasm) area of skin-like differentiation, so a tissue that is foreign to that site
hamartomas are tumor (not neoplasm, but some are maybe a neoplasm) that forms a tissue native to that site, but not formed as it would be normally
corneal dermoids have stratified keratinized squamous epithelium and variable pigment, over irregular dermis with hair, adnexa, rarely cartilage or bone, and blends with the corneal epithelium and corneal stroma. It is not hyperplasia it is a congenital developmental abnormality and therefore metaplasia would also be the wrong term.
Conjunctivitis in cats is most often caused by?
A. Autoimmune disease
B. Helminth parasites
C. Concurrent neoplasia
D. Viral or bacterial infection
D. viral or bacterial infection
in cats conjunctivitis is vast majority caused by infectious etiologies like FHV1 and Chlamydophila felis
In dogs most conjunctivitis is autoimmune keratoconjunctivitis sicca or allergy
In horses myiasis (Habronema, Draschia) are more likely than in other species. In cattle pink eye (Moraxella bovis) will cause central suppurative ulcers in the cornea with conjunctivitis, if just conjunctivitis BHV1 (IBR) can be considered more strongly and often causes little white nodules from lymphofollicular hyperplasia.
conjunctivitis in all species is a rather boring stereotypical response, regardless of cause
Feline lipogranulomatous conjunctivitis is most similar to ____ in the dog?
A. chalazion
B. bacterial infection
C. external hordeolum (stye)
D. dacryoadenitis
A. chalazion
felione lipogranulomatous conjunctivitis is characterized by aggregates of foamy macrophages in the eyelid margins (no specific mention of Meibomian adenomas) but histologically indistinguishable from canine chalazions no discrete granuloma, and no neutrophils (in dogs almost always associated with Meibomian adenoma when we see surgical biopsies)
other types of conjunctivitis in cats typically have an infectious etiology
external hordeolum is SUPPURATIVE adenitis of the adnexal glands of Zeis or Moll
Dacryoadenitis in dogs (lacrimal gland inflammation) is associated with keratoconjunctivitis sicca, characterized by T-helper lymphocytes
What are the primary basic responses of the cornea to injury?
A. suppurative inflammation
B. Neovascularization
C. Epithelial/stromal death and metaplastic keratinization
D. Hyperpigmentation
C. epithelial/stromal death and cutaneous metaplasia
the cornea is AVascular and contains NO leukocytes so vessels and leukocytes, and infiltrating pigment cells are secondary to the corneas primary response to injury. If acute/severe the epithelium, stroma, and endothelium die, if chronic and mild the cornea attempts to “return to its embryologic origins” as skin so cutaneous metaplasia keratinization occurs first with subsequent vascularization then leukocytes/pigment
all keratitis is a response to “injury” since it is an immune privileged site there is no such thing as a primary keratitis alone.
Which lesion is most specific for eye disease caused by Moraxella bovis in cattle?
A. Lymphoplasmacytic conjunctivitis
B. Corneal edema
C. Central corneal ulceration
D. Corneal stromal crystalline deposits
C. CENTRAL corneal ulceration is most specific for Moraxella bovis infection
other causes of corneal ulcers may present more peripheral as extensions of conjunctivitis/dermatitis. Corneal edema is super non-specific and so are characteristic lesions seen in conjunctiva. Especially lymphofollicular hyperplasia and chronic lymphocytic inflammation
Corneal stromal crystalline deposits are characteristic of Corneal dystrophies (congenital defects) seen in DOGS and cause corneal edema, but do not progress to inflammation unless the swelling injures the corneal epithelium, etc
Corneal endothelial dystrophies are most commonly seen in what species?
A. Dogs
B. Cats
C. Cattle
D. Horses
A. dogs are the most common accounting for almost all examples and they affect 30 different breeds for example Boston Terriers, Chihuahuas, Dachshunds, German Shepherds
The only one mentioned in cats:
A rare, juvenile-onset, genetically transmitted endothelial dystrophy in Manx and domestic shorthair cats is manifest as bilateral, progressive central epithelial and stromal edema. Fluid accumulates within superficial stroma and within the epithelium. Primary morphologic abnormalities are not described in the Manx, but in shorthairs there is irregularity and vacuolation of corneal endothelium. JKP vol 1 433
Canine persistent (recurrent) ulcer syndrome was first described in what breed?
A. German Shepherds
B. Boston Terriers
C. Boxers
D. Chihuahuas
C boxers
Canine persistent (recurrent) ulcer syndrome was first described in Boxer dogs (hence the old name “Boxer ulcer”).
Pannus keratitis is common in what species (and breed) with what associated etiology?
A. Quarter horse, Pseudomonas
B. German Shepherd dog, idiopathic
C. Boxer dog, idiopathic
B. German Shepherd dogs, or related/morphologically similar dog breeds. it is idiopathic at this point. Corneal vascularization ingrowth from sclera and pigmentation, NO ulcer, often infiltrates of plasma cells form “plasmoma”
Boxer dogs get “Boxer ulcer” a non-specific chronic canine persistent (recurrent) ulcer syndrome
horses get corneal sequestrum (any breed) following non-specific corneal injury these ulcers can often have secondary fungal or Pseudomonas infections, Pseudomonas is associated with keratomalacia (melting ulcer)
