Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

ophtho final > posterior segment > Flashcards

posterior segment Flashcards

1
Q

structures in posterior segment

A

vitreous humor

retina

optic nerve

choroid-tapetum

posterior sclera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

vitreous development

A

primary vitreous-hyaloid artery, nourishment during embryogenesis, regression start d45 gestation, complete by postnatal d14

secondary vitreous: adult vitreous body

tertiary vitreous: lens zonules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

vitreous composition

A

water (98%) hyaluronic acid, collagen

semi-solid gel

transparent and colorless

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

functions of vitreous

A

globe structure and growth

metabolism

refraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

retinal development

A

two layers of neuroectoderm apposed during invagination of optic cup

outer layer–>retinal pigmented epithelium

inner layer–>neurosensory retina

potential space between RPE and NS retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

retinal pigmented epithelium

A

outermost retinal layer

contains melanin-except dorsal half, allow visualizationof tapetum, lesser amounts in color dilute animals

functions: metabolism, phototransduction

vascular supplied by choroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

retinal blood vessels

A

within inner aspect of NS retina

nourish inner retina only

short posterior ciliary arteries-arise around optic disc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

retinal vascular patterns

A

Holangiotic

paurangiotic

merangiotic

anangiotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

holangiotic

A

dog, cat, cow

vessels across most of retinal surface

most common pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

paurangiotic

A

horse

vessels extend only a short distance around optic disc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

merangiotic

A

rabbit

vessels extending medially and laterally only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

anangiotic

A

birds, reptiles

no retinal vessels

pecten, conus papillaris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Mueller cells

A

structural and metabolic roles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

nerve fiber layer

A

axons of ganglion cells

form optic nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

photoreceptors

A

absorb photons, convert to electrical impulses

rods, cones

cells bodies in outer nuclear layer

outer segments interdigitate with RPE cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

rods

A

scotopic vision

motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

cones

A

photopic vision

color

high-resolution vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

area centralis

A

higher concentration of cones

photoreceptor

dorsolateral to optic disc

fovae in some species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

light transmission

A

light entering eye first absorbed by PR

transmitted though layers to NFL

from NFL to optic nerve

impulse along optic nerve to optic chiasm

optic tract to lateral geniculate nucleus, pretectal nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

optic nerve

A

axons from ganglion cell layer mature towards optic stack

converge at optic disc, axons bundle together to form optic nerve

continue posteriorly: optic chiasm and optic tracts

transmission of impulses from eye to CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

location of optic nerve: dogs and cats

A

near tapetal/nontapetal junction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

location of optic nerve: horses

A

within nontapetal fundus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

choroid includes:

A

blood vessels

tapetum

melanocytes

connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

choroidal blood vessels

A

supply outer retina

larger vessels: parallel to retina, osmotic gradient pulling fluid out of RPE

choriocapillaris: perpendicular to retina, supplies outer retina, “Stars of Winslow”-end of capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
tapetum
inner choroid superior half of globe triangular reflectivity and color depend on composition increases available light absent in diurnal, most primates, most birds and reptiles, pigs
26
sclera
outer fibrous tunic: collagen, fibrocytes, melanocytes, cartilage and bone in some spp insertion of EOM lamina cribrosa-sieve like optic nerve exit
27
subalbinotic: variation of normal
color dilute animals decreased melanin in RPE allows visualization of choroidal vessels tapetum may be absent
28
neuro-ophthalmic exam
testing intergrity of visual pathways Menase response dazzle PLR
29
menace response
CN II, VII, cortex, cerebellum some vision
30
dazzle
CN II, subcortical visual pathways does not test vision
31
pupillary light reflex
direct and consensual CN II, III does not test vision
32
fundic examination
use indirect ophthalmoscope or direct fundoscopy, PanOptic
33
ultrasound
when fundus is not visible retinal detachment masses vitreous debris
34
electroretinogram (ERG)
retinal function-PR electrical potential generated when photons strike PR indications: assessment of retinal function when fundus is not visble or is normal in appearance
35
blurry images
entire image should be in focus at same time if not, objects in different planes-depressed lesion, raised lesion, retinal detachments
36
optic nerve changes
shape: coloboma, growths (neoplasia, excessive myelin) color: red (bleeding), dark (atrophy) borders: should be distinct, indistinct indicate optic neuritis size: small (micropapilla, atrophy), large (optic neuritis)
37
vascular changes
tortuosity engorgement hemorrhage vessel attenuation lack of vessels across nerve head (dogs)
38
tapetal changes
hyperreflectivity hyporeflectivity
39
nontapetal changes
depigmentation infiltrates hemorrhage
40
Persistent hyaloid artery
failure of regression of hyaloid artery complete or partial patent or nonpatent may be associated with cataract rarely requires tx
41
vitreous degeneration
breakdown of gel structure vitreous liquefies may prolaspe anteriorly-could plug drainage channel may predispose to retinal detachment normal aging change post-inflammatory no tx needed
42
asteroid hyalosis
calcium and phospholipid precipitates in vitreous "floaters" normal aging change no treatment needed
43
vitritis
inflammation of the vitreous extension of chorioretinitis RBC, WBC, proteinaceous debris very slow turnover
44
micropapilla & optic nerve hypoplasia
congenitally small optic nerve uni or bi lateral +/- blindness no tx hypoplasia-A, normal-B
45
retinal dysplasia
abnormal differentiation of retinal layers nonprogressive may now be predisposed to retinal detachments, visual deficits and blindness acquire: Feline panleukopenia, k9 Herpesvirs, BVD
46
retinal dysplasia types
folds-liniear, hyporeflective or white, raised geographic-horseshoe shape, dorsal renital venule complete: retinal detachment, blind
47
retinal dysplasia tx
none-few folds, no behavioral signs of vision loss periodic monitoring-more extensive retinal area affects, looking for retinal detachment
48
Collie eye anomaly (CEA)
abnormal mesodermal differentiation bilateral polygenic lesions: Choroidal hypoplasia-temporal to optic disc, posterior polar coloboma, retinal detachment, hyphema
49
What does "go normal" mean in regards to Collie eye anomaly?
as dogs age, their RPE melanin increases which can mask underlying hypoplasia screening for CEA should be performed by 8 weeks of age
50
tx for collie eye anomaly
usually none-possible sx for retinal detachment breeding programs to minimize DEA within population
51
taurine deficiency
feline central retinal degeneration normally-high taurine concentrations in photoreceptors and heart muscle PR degeneration-tapetal hyperreflectivity, begins in area centralis (superior and temporal to optic disc), enlarges into a ellipse extending nasally, eventually diffuse concurrent dilated cardiomyopathy
52
taurine deficiency dx and tx
confirm with blood taurine levels taurine supplementation-will stop progression but not reverse changes, will reverse cardiomyopathy
53
progressive retinal atrophy (PRA)
inherited photoreceptor degeneration bilateral, symmetrical progressive vision loss over months early onset or later onset
54
typical hx of patient with PRA
purebred dog/cat, young adult visual deficits first noted at night or dim light slowly day viison also compromised abnormalities occur and worsen over months
55
PE findings for PRA
resting mydriasis slow to absent PLR meance may be absent retinal vascular attenuation tapetal hyperreflectivity dark optic disc severeity of examination findings correlates stage of disease
56
Tx for PRA
none due to inherited nature, avoid breeding affected or carrier animals
57
sequela of PRA
cataracts almost all dogs may occur years after PRA dx progressive lens-induced uveitis must be managed to avoid painful complications-glaucoma, lens luxation
58
Sudden acquired retinal degeneration syndrome (SARDS)
dogs bilateraly symmetrical, idiopathic, acute retinal degeneration predisposed: middle age, FS, overweight, more common in winter
59
Typical hx for SARDS
sudden blindness (within 1 day) cushing's-like signs PU,PD, PP, blood work ofte shows increased ALP, lymphopenia, increased chol
60
SARDS examination findings
resting mydriasis normal or slow PLR menace absent normal funduscopic exam confirm blindness with electroretinogram-no waveform
61
tx for SARDS
no proven effective therapy

ophtho final (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions