Special Senses Flashcards
(114 cards)
1
Q
Fibrous tunic
A
Sclera and cornea
2
Q
Vascular tunic
A
Choroid, iris, ciliary body (pars plicata and plana)
3
Q
Retinal/neural tunic
A
Retina
Neural part
Pigmented part
4
Q
Eye development
A
Outgrowth of forebrain (optic vesicle- paired/symmetric)
ectoderm invagination -> lens placode -> lens
mesenchyme = sclera and CT of uvea
5
Q
Anopthalmia
A
Rare
No development of the primary optic vesicle- bilateral
6
Q
Micropthalmis
A
Miniature, disorganized globe in an orbit of relatively normal size
Involution after exogenous injury (infection, trauma, ischemia)
Calf with BVD, Lambs with border dz
7
Q
Cyclopia/synophthalmos
A
In lambs:
Incomplete separation of orbits in development
Veratrum californicum ingestion on d 14 gestation
8
Q
Coloboma
A
Notch like defects of optic disk, retina, uvea
Bc defective closure of embryonic fissure of eye
Portions of retina accidentally grow outwardly of the defect
9
Q
Collie eye anomaly
A
Scleral extasia
common disease of smooth and rough collies- inherited, auto reces
Retinal vessel tortuosity
focal to diffuse choroidal and tapetal hypoplasia
optic nerve coloboma
retinal separation with intraocular hemorrhage
always bilateral
10
Q
Corneal dermoid
A
Failure of fetal ectoderm to undergo complete development as corneal epithelium and remains as haired skin
11
Q
Choristoma
A
Mass of normal tissue in an abnormal location
12
Q
Glaucoma
A
Sustained increased intraocular pressure
=blindness bc pressure on retina on optic nerve disc cupping
leading cause for enucleation
increased production of aqueous humor/decreased removal
primary=developmental
secondary=acquired (injury, neoplasia)
13
Q
Exopthalmus
A
Protrusion of a normal sized globe
often from space occupying mass
14
Q
Bupthalmos
A
normally positioned globe that is enlarged bc IOP
15
Q
Proptosis
A
eye outside orbit
16
Q
Entropion
A
inward rolling of eyelid
17
Q
Ectropion
A
external folding of eyelid margins
18
Q
Distichiasis
A
Ectopic row of cilia originating from ducts of meibomian glands
19
Q
Trachiasis
A
misdirection of the normal cilia so that they contact the cornea
20
Q
Chalazion
A
focal region of inflammation in response to leakage from meibomian gland secretions
21
Q
Blepharitis
A
Inflammation of the eyelid
22
Q
Dacryocystitis
A
Inflammation and blockage of nasolacrimal ducts-can form fistulous draining tracts
probs with dentition, blockage, underlying infection
CS: runny eyes, stained fur, conjunctival redness, swelling, painful mouth/face, dec appetite
Predisposing factors: environmental irritants, flies, age, skin, etc
23
Q
Conjunctivitis
A
Response to injury
Hyperemia, swelling/edema, discharge, chemosis, pigmentation
primary pathogens rare, G+ bact = normal flora (G- =significant)
Cats: FHV-1, Chlamydophilia felis, myoplasma felis
Cow: IBR, M bovis, MCF
Suppurative conjunctivitis
2ndary bact infection
2ndary to altered anatomic conformation of eyelids
24
Q
Chemosis
A
severe conjunctival edema not covered by semi-rigid skin and can expand readily
25
Myxedema
facial swelling as result of low thyroid levels
26
Thelazia
Only true ocular parasite- adults inhabit conjunctival sac/lacrimal ducts
Transmitted by face flied
27
Cherry Eye
Prolapse of the gland of 3rd eyelid/nictitating membrane
28
Squamous cell carcinoma
Abnormal, malignant cell growth originating from the epithelium of the eyelid
29
Meibomian adenoma
Abnormal, benign multilobulated growth originating from the meibomian gland
30
Melanoma
Eyelid- benign in K9s; conjunctiva-malignant
melanocytes start to replicate and produce pigment uncontrollably resulting in a visible change in the epithelium of the eyelid or conjunctiva
31
Unlikely to be underlying risk factor for conjunctivitis
Systemic bacterial infection
32
corneal opacity causes
edema, deposits
33
Corneal edema
inj to epithelium, endothelium, ketatitis
34
Corneal endothelial dystrophy
Inherited
inborn errors of metabolism -> death of corneal endothelial tissue
no inflam
bilateral, symmetrical, lateral -> diffuse over months
DDX corneal stromal dystrophy (stromal deposit
35
Keratitis
Neovascularization has leaky capillaries
inflammation of cornea
from trauma,
bact (opportunistic- p aeruginosa; m bovis; chlamydia/myco)
fungi (aspergillosis, mucomycosis)
virus (IBR, MCF, FHV)
idiopathic (chronic superficial keratitis in GSD, indolent ulcer-boxers, FE eosinophilic)
corneal edema distorts pupil, hyperemia of bulbar conjunctiva, iris neovascularization
36
Injury to epithelium
Ulceration -> blue appearance
| pupil difficult to discern
37
Inj to endothelium
Inc IOP, corneal endothelial dystrophy, immune mediated
38
Keratomalacia
Melting ulcers
necrosis of corneal epithelium and stroma
WBC inj, bact/fungal infection (P aeruginosa)
= descemetocele
39
Descemetocele
anterior herniation of an intact descemet membrane through an overlying stromal defect
no regen possible
40
Keratoconjunctivitis Sicca
Dry eye
immune mediated inj to lacrimal gland -> decreased tears and/or change in composition of tears -> drying out of cornea/conjunctiva -> chronic irritation -> mucopurulent exudate
lacrimal gland inj, hypothyroid, drugs, infection (distemper)
41
Indolent/perisitent ulcer
Epithelium is thickened and disorganized and has failed to adhere to the adjacent corneal stroma,
ineffective healing
42
Corneal sequestrum
Localized necrosis of the epithelium and anterior stroma from severe corneal injury
affected area= infiltrated with dark pigment- present in the tear film -> black lesion in cornea
43
Corneal pigmentation
from entrapped uvea
| melanin in response to inj (chronic keratitis)
44
Corneal lipidosis
Breed predilection, associated with hyperlipidemia
| somewhat crystalline
45
Tropical Keratopathy
Corneal lesion that is associated with the loss of corneal stroma assocaiated with dense accumulations of collagen in the superficial stroma
46
Anterior uveitis
Inflammation of the iris (iridis) and ciliary body
47
Posterior uveitis
Inflammation of the choroid (choroiditis)
48
Chorioretinitis
Inflammation of the choroid and retina
49
Endophthalmitis
Inflammation of the uvea, retina, vitreous
50
Panophthalmitis
Inflammation of uvea, retina, vitreous, cornea, and sclera
51
Uveitis causes
Hypersensitivity, infections, lens-induced
52
Uveitis- hypersensitivity
Fe idiopathic lymphoplasmacytic uveitis
equine recurrent uveitis
sporadically associated with other systemic inflammatory diseases
53
uveitis- infection
usually due to systemic disease and the uvea is one of many vascular tissues affected
FIP, systemic mycoses etc
perforating corneal ulcers
penetrating injuries
54
Uveitis
```
Keratic precipitates
dyscoria
pupil visible
rubeosis iridis
hypopyon
```
55
dyscoria
irregularly shaped pupil due to posterior synechia
56
Hypopyon
pus in the anterior chamber
| typically severe inflammation of the iris and ciliary body or from vasculature (sepsis)
57
Rubeosis iridis
blood vessel proliferation along surface of the iris
58
synechia
anterior (between iris and cornea) and posterior (between iris and lens) fibrous adhesions
59
uveitis consequences
synechia, preiridal fibrovascular membrane (PIFM), cataract (inadequate aqueous flow or posterior synechia), lens luxation, 2ndary glaucoma (filtration angle block by exudate or adhesions), retinal detachement, phthisis bulbi
60
phthisis bulbi
shrunken, non functional, thickened cornea
| end stage eye damage that results in scarring, inflammation, and globe disorganization
61
Equine recurrent uveitis
Moon blindness- most common cause of blindness in horses
variable degree of uveitis in one or both eyes
association with hypersensitivity to previous systemic infection (lepto, oncocerca cervicalis)
can progress to phthisis bulbi
62
Lens induced uveitis
inflammatory response to lens protein
63
Phacolytic
leakage of lens proteins from hypermature cataract
64
phacoclastic
rupture of the lens
65
Goniodysgenesis
congenital malformation of the iridocorneal angle/trabecular meshwork that results in primary glaucoma
66
Persistent pupillary memebrane
a vascular tunic that supplies the lens during early development has failed to regress
67
Aniridia
absence of the iris
68
Iris hypoplasia
the iris doesnt fully develop
69
Feline diffuse iris melanoma
most common intraoccular neoplasm- esp cats with yellow eyes
most=malignant (raised lesions, velvet surface, distortion of pupil/iris)
rate of glaucoma high
70
Uveal melanoma
most common intra-ocular neoplasm
| most=benign in dogs
71
Ciliary adenoma/carcinoma
Dogs > cats
most = benign (even if histologically malignant)
discrete nodules in posterior segment
get: 2ndary glaucome, hyphema, retinal detachment
72
Hyphema
blood within aqueous fluid of anterior chamber due to vessels in the uvea or retina having primary vascular lesions or a hemostasis disorder
73
intraocular sarcoma
unique to cats, from ocular trauma
malignant- loves to invade after Sx and ocular n
probs derived from lenticular epithelium
74
Uveal lymphoma
Most common metastasis with eye- cats
thickening/pallor of uvea
clinically difficult to distinguish from uveitis
75
lens transparent bc
cells fit together in regular arrangement that limits scattering
simplicity of cells (no nucleus, organelles)
lack of BV in postnatal animal
dehydration- relies on aqueous humor
76
lens response to injury
hydropic swelling of injured fibers- fiber fragmentation and disintegration
hyperplasia and fibrous metaplasia of lens epithelium, formation of foamy bladder cells
posterior lens epithelial migration
when chronic (hypermature): shrinking and wrinkling of lens capsule and mineralization
77
Cataract
most common disease of the lens
swelling/degen of lenticular fibers -> opacity
painful, effects vision, may need tx
78
cataract causes
DM, age, inherited disposition
79
Cataract- DM
```
inc sorbitol
lens degeneration and swelling
influx of proteins and ions
proteolytic enzyme activation
change in lens proteins
cataracts
```
80
lenticular (nuclear) sclerosis
senile change of pupil appearance
not painful, more fiber deposits at the edge of lens
will adjust vision, no tx needed
81
Lens luxations
Congenital, spontaneous, trauma, glaucoma
| when lens shift out of position and moves either anteriorly or posteriorly in the eye
82
Microphakia
abnormally small lens also seen with micropthalmia
83
Lentiglobus
a malformation of the lens and occurs when the anterior or posterior aspect of the lens is prominent and spheroid in shape
84
lenticonus
a rare congenital anomaly of the eye characterized by a conical protrusion on the crystalline lens capsule and the underlying cortex
85
primary glaucoma
```
from goniodysgenesis (congenital)
dogs (inheritied, common), other (anomalous)
open angle glaucoma- no visible structural abnormality in trabecular meshwork
Beagles
```
86
secondary glaucoma
most common,
from anything that obstructs the pupil or trabecular meshwork
exudation, lens luxation, posterior synechia, peripheral anterior synechia, compression of the filtration angle
87
glaucoma consequences
```
Buphthalmos (inc IOP)
corneal edema +/- striae
retinal degeneration/atrophy
optic disc cupping
optic nerve atrophy (loss of ganglion cells)
cararact (stagnation of aqueous/malnutrition of lens)
lens luxation
iris atrophy
```
88
stiae
splitting and streaks in descemets membrane as a result of stretching
89
Retinal degen/atrophy
senile change, inherited metabolic defect of photoreceptor cells (Progressive retinal atrophy PRAs)
Sudden acquired retinal degeneration syndrome (SARD)
toxicity (baytril, loss of photoreceptor, outer nucleus, and plexiform layers)
metabolic deficiencies (taurine, vit A)
inc IOP (glaucoma)
retinal detachement (inc IOP and vitreous body v
90
Retinitis
Usually extension from choroiditis or encephalitis
neurotropic viral infections (rabis, distemper)
visceral larval migrans (toxocara)
consequences: scarring (gliosis) atrophy
91
retinal dysplasia
jumbling of retinal layers that develop due to retinal injury via viruses or an inherited condition
92
retinal detachment
separation between neural and pigmented layers of the retina that can be due to choroiditis, retinitis, hemorrhage, neoplasm, trauma, or systemic hypertension
93
Auricular hypoplasia (microtia)
predesposed breeds
La mancha goat- incompletely dominant trait- distorted auricular cartilage
scottish fold cat- autosomal dominant
94
Otitis externa
```
external ear canal inflammation- v common
2ndary bact (staph, strep, proteus, pseudo, malassezia )
underlying factors (allergies, skin dz, extoparasits, moisture, neoplasm, FB, ear shape)
```
95
Otitis externa consequences
fibrosis, adenexal atrophy and hyperkeratosis, osseous metaplasia of auricular cartilage resulting in stenosis of acoustical meatus, constant/recurring ear infections, middle/inner ear infection
96
Otorrhea
discharge from ear
97
Otorrhagia
hemorrhage from the ear
98
Otodynia/otalgia
pain from manipulation of the ear
99
Otiasma
foul smelling otorrhea
100
auricular hematoma
commonly seen in dogs, pigs, occasionally cats
caused by trauma, usually from excessive head shaking -> centrifugal shearing forces fracture cartilage and lacerate blood vessles
underlying ear disease is common
101
Parasites of ears
Otodectes cynotis: fe and k9 ear mite
Psoroptes caniculi: rabbit/ruminant ear mite
asian long horned tick: pets, livestock, people- transmits babesia and theileria
102
Auricular infarction
from sepsis (bact, FIP), immune mediated vasculitis (type 3 HS), frost bite, toxins (ergot alkaloids)
103
proliferative necrotizing otitis externa
Cats- young
unknown etiology
can resolve spontaneouslt
inflammation of the external ear
104
Auricular plaques
equine ear papillomas
raised hyperkeratotic plaques
caused by papillomavirus spread by fly bites
105
Squamous cell carcinoma
excessive cell growth in hypopigmented regions of external ear
become ulcerated and blackened at margins
can be bilateral
106
Ceruminous neoplasia
most common neoplasm of external acoustic meatus of dogs and cats
adenoma=dog
carcinoma=cat
2ndary to chronic inflamm?
107
Otitis media
inflammation of the middle ear
from tympanic membrane perforation, ascension via auditory tube, hematogenosu
almost always bacterial: pasteurella, trueperella, mycoplasma, histophilus
108
Otitis media consequences
Facial n paralysis, head tilt, drooping ears
inflammation/perforation of tympanic membrane
erosion of auditory ossicles
horner's syndrome (ptosis, miosis, enophthalmous, etc)
osteosclerosis of tympanic bulla
formation of inflammatory polyps (non neoplastic inflam dz cats, dense fibrous tissue covered by epithelium, from middle ear or pharynx)
progression to otitis interna (meningitis)
goblet cell metaplasia and impaired mucociliary clearance
109
enophthalmous
sunken in eye
110
Aural abscesses
```
Turtle/tortoises
nutritional vit A deficiency
2dary bact infection
immunosuppression
poor environmental conditions
```
111
Otitis interna
Inflammation of inner ear
| extension from otitis media +/- osteomyelitis of petrous temporal bone
112
Consequences of otitis interna
```
extension through internal acoustic meatus along CN VIII -> meningitis
vestibular dz (head tilt, nystagmus, ataxia, circling, facial paralysis)
sensory hair cell loss (permanent hearing impairement
```
113
Deafness- aquired
Aquired sensorineural deafness
genetic defect assocated with defen of neuroepithelial cells in organ of corti
prenatal or perinatal events from transplacental exposure to ototoxic compounds (gentamicin and cisplatin)
114
Deafness- hereditary
congenital sensorineural deafness
primary degeneration of stria vascularis,
collapse of reissner's membrane (vestibular)
organ or corti degen (blue irides, retinal pigmentation absence, partial albinism)
blue eyed white cats, dalmations
