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Ophthamology > uvea > Flashcards

Flashcards in uvea Deck (55):
1

function of uveal tract

vascular supply

light regulation

blood aqueous barrier

accomodation

formation of aqueous humor

2

nonpigmented epithelium of the ciliary body

epithelial portion of BAB-tight junctions

formation of aqueous

active aqueous production

bicarbonate

 

3

heterochromia iridis

>1 color in 1 iris or between 2 irides in 1 animal

often concurrent coat color dilution

usually incidental

A image thumb
4

persistsent pupillary membranes

remnants of embryonic vasculature

airse from iris collarette

usually resorbed by 6 weeks of age

iris to iris-incidental

iris to lens-cataract

iris to cornea-corneal opacity

no therapy

A image thumb
5

Merle ocular dysgenesis

associated with Merle gene

Dachshund, collie, australian shepherd, great dane

heterochromia iridic

iris hypoplasia

iris coloboma-chunk of iris missing

corectopia-pupil in wrong spot

no tx

6

Uveal cysts

arise from pigmented epithelium of iris and/or ciliary body

spontaneous in formation or in response to inflammation

free floating or anchored

main r/o: melanoma

Dx by characertistic appearance, transillumination

usually incidental

usually no tx

7

iris atrophy

age related thinning of the iris-moth eaten appearance, scalloped pupillary margin

diminished PLRs

dyscoria

no therapy

8

Primary uveal neoplasia

cats & horses-Melanoma

dogs-melanocytic neoplasia

9

feline diffuse iris melanoma

insidious hyperpigmentation of the iris face

r/o: benign melanosis/nevus

could be metastasis from liver, lungs, regional LNs

10

differentiating between feline diffuse iris melanoma and benign melanosis/nevus

raised from iris surface-Purkinje 2 image raised

rapid spread

distortion of thickening of iris

interference with pupil shape or function

extension into sclera

associated uveitis or glaucoma

extent of hyperpigmentation

11

feline diffuse iris melanoma tx

continued monitoring-take photo

laser photocoagulation-small lesions only could disperse neoplastic cells

enucleation:histopath

12

Canine uveal melanocytic neoplasia

usually in anterior uvea

DDx: uveal cyst, limbal melanoma

Dx: transillumination, U/S, gonioscopy

Tx: monitor with photos, laser photocoagulation-small, enucleation-histopath

13

secondary uveal neoplasia

lymphosarcoma

DDx: uveitis

clin sxs: uveitis, nodules on iris, diffuse thickening of iris, destruction of iridal architecture

14

uveal neoplasia: tx

primary-sector iridectomy, laser ablation, enucleation

secondary: chemotherapy, enucleation

15

blood ocular barriers

prevent movement of porteins, low-molecular weight solutes into the eye

tight junctions

 

16

Uveitis

inflammation of the vascular tunic of the eye

breakdown of the blood-ocular barrier

protein and inflammatory cells present

17

anterior uveitis

iris and/or ciliary body

iridocyclitis, iritis, cyclitis

18

posterior uveitis

choroid

choroiditis, chorioretinitis

19

panuveitis

anterior and posterior uveitis

20

endophthalmitis

panuveitis and inflammation of the ocular cavities

21

panophthalmitis

all tunics of eye inflamed

22

clinical signs of anterior uveitis

non-specific signs: blepharospasm, elevated third eyelid, epiphora

more specific sxs: episcleral injection, deep corneal vascularization, corneal edema, aqueous flare, miosis, hypopyon, keratic precipitates, hyphema, iris swelling congestion, anterior chamber fibrin, rubeosis iridis, iris color change, iris hemorrhage

23

does absence of aqueous flare rule out uveitis?

no!

24

aqueous flare

aka Tyndall phenomenon, plasmoid aqueous

cells, proteins, inflammatory debris within aqueous reflect light

light beam traversing the anterior chamber-connecting Purkinje images 1 and 2

presence of flare=anterior uveitis

25

miosis

restriction of the pupil

also resistance to pharmacologic dilation

26

hypopyon

white cells in the anterior chamber

27

keratic precipitates

inflammatory debris on corneal endothelium

found on posterior side of purkinje image 1

like a scar

28

hyphema

blood in anterior chamber

29

clinical signs of posterior uveitis

vitreous opacities, tapetal hyporeflectivity, retinal hemorrhage, altered pigmentation of nontapetal fundus, retinal detachment

30

tapetal hyporeflectivity

indicates active lesion

cells or fluid obscuring view of tapetum

31

diagnosis of uveitis

clinical hx: red eye, cloudy eye, squinting, tearing, visual deficits, blindness, signs of systemic dz

hypotony (<10 mmHg)

32

diagnostic work up

first:  complete PE, CBC, Chem23, UA, FIV/FeLV test

second: thoracic/abdominal rads, abdominal u/s, LN aspirates, ocular u/s, aqueous or vitreous aspirates, histopath

33

potential etiologies

immune-mediated/idiopathic, neoplastic, infectious

pretty much anything

34

idiopathic

most common "cause" 

dx of exclusion

more likely to be unilateral vs bilateral

35

systemic disease etiology

more likely bilateral than unilateral

36

lens induced uveitis

T cell tolerance to low levels of lens antigen

increased exposure to antigen overwhelms this tolerance

antigen in anterior chamger incites intraocular inflammation

pacolytic uveitis vs phacoclastic uveitis

cataract removal

37

phacolytic uveitis

slow leakage of lens protein

most obvious with hypermature/resorbing cataract

chronic, low grade inflammation

38

phacoclastic uveitis

sudden release of lens protein

secondary to penetraing ocular trauma, lens rupture

rapid progression, severe inflammation

39

Golden retriever uveitis

pigmentary uveitis of golden retrievers

unknown pathogenesis

average age 8.6 years

Characteristics: uveal cyst formation, increased iris melanin, melanin deposition on lens capsule (radial), Glaucoma, cataract

dx: clinical appearance

no effective treatment/anti-inflammatories

leads to blindness and glaucoma

40

FeLV/FIV

FeLV itself doesn't cause uveitis

secondary to superinfection, lymphoma, anemia, spastic pupil syndrome

FIV-Direct viral tissue damage, superinfection

41

FIP

ocular lesions more common in dry form

granuloma formation, vasculitis, immune complex deposition

"mutton fat" keratic precipitates

42

Canine distemper virus

chorioretinits +/- optic neuritis

43

therapy for uveitis

treat underlying cause, address inflammation, address pain, minimize sequelae

abx-topical if ulcer present, systemic if uveitis caused by infection

44

anti-inflammatory therapy

very important

topical if anterior only

need systemic if posterior involved

Corticosteroids, NSAIDs, Other immunomodulating drugs

45

Topical corticosteroids

first choice for anterior uveitis

predniolone acetate, dexamethasone

NOT hydrocortisone

CI if corneal ulcer is present

high dose at first then taper off

caution in small dogs, cats and diabetics

46

systemic corticosteroids 

prednisone, prednisolone

anti-inflammatory to immunosuppressant doses-gradually taper

can be used wtih topical meds

can be used in the presence of corneal ulcer

first r/o infectious dz

do not use with NSAIDs

47

Topical NSAIDs

diclofenac, flurbiprofen, nepafenac

may be used alone or with topical and/or sytemic corticosteroids

frequency of use depends on severity of inflammation

problems: decrease aqueous outflow, incite collagenolysis, inhibit platelet aggregation, systemic absorption

caution in cats, small dogs, concurrent renal disease

48

Systemic NSAIDs

Carprofen, meloxicam, tepoxalin, etc

may be used toa ugemtn topical medication

may be used with infectious disease

do not use with systemic corticosteroids

49

pain management

anti-inflammatory therapy

mydriatic/cycloplegic therapy (atropine)

50

atropine

parasympathetic/anticholinergic

stabilizes blood-aqueous barrier

onset 30-60 mins; slowed with inflammation

use lowest dose required to achieve mydriasis

Cycloplegic-paralysis of ciliary body

decreases formation of posterior synechia

CI if glaucoma present, KCS

may cause profuse salivation

51

patient monitoring

recheck 1 weeks after dx

check IOP, severity of aqueous flare, appearance of clinical signs

52

Synechia

anterior-cornea to iris

posterior-iris to lens

arise from pupillary zone or peripheral ciliary zone

53

Sequelae of uveitis

synechia

iris atrophy

cataract

lens luxation

Glaucoma

iris bombe

phthisis bulbi

chorioretinal scarring

54

iris bombe

360 degrees posterior synechia

prevent movement of aqueous from posterio chamber to anterior chammber

narrows idiocorneal angle

elevation of IOP

55

Chorioretinal scarring

 tapetal hyperreflectivity with pigment clumping