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Ophthalmology > Sclera/Cornea > Flashcards

Sclera/Cornea Flashcards

1
Q

What is the anterior and posterior portion of the fibrous tunic

A

Anterior: Cornea
Posterior: Sclera

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2
Q

What are the different layers of the sclera

A

1) Episclera- vessels and nerves
2) Sclera proper- dense fibrous
3) Lamina fusca- inner elastic layer

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3
Q

What is the inner most elastic layer of the sclera

A

Lamina fusca

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4
Q

What layer of the sclera contains vessels and nerves
cannot be moved

A

episclera

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5
Q

What is the dense, fibrous later of the sclera

A

sclera proper

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6
Q

junctional zone between sclera and cornea

A

limbus

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7
Q

Collagen arrangement in the sclera is ______ while the cornea is _______

A

Sclera: random
Cornea: ordered

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8
Q

opening in the sclera for the optic nerve

A

lamina cribrosa

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9
Q

why might the cat and horse be more resistant to optic nerve damage with glaucoma

A

cats have elastic lamina cribrosa

dogs have a rigid lamina cribrosa which means as globe stretches, ganglion cells get compresses

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10
Q

congenital malformation of the eye causing a defect in the lens, iris, retina, sclera, optic disk
usually optic disk

A

Coloboma

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11
Q

coloboma is most common in what breeds

A

Collies- Collie eye syndrome (anomaly) CEA

Australian Shepherds- multiple ocular anomaly (MODS)

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12
Q

multiple ocular anomaly (MODS)

A

coloboma present in Australian shephards
congenital malformation of the eye causing a defect in the lens, iris, retina, sclera, optic disk
usually optic disk

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13
Q

Collie eye anomaly (CEA)

A

coloboma present in collies
congenital malformation of the eye causing a defect in the lens, iris, retina, sclera, optic disk
usually optic disk

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14
Q

Coloboma

A

congenital malformation of the eye causing a defect in the lens, iris, retina, sclera, optic disk
usually optic disk
-Collies and Australian Shephards
ex:
1) Microphthalmia
2) Iris colobomas
3) Optic nerve coloboma

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15
Q

What are different scleral diseases

A

1) Inflammatory- episcleritis/scleritis
2) Neoplasia- usually arises at limbus
3) Trauma

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16
Q

neoplasia of the sclera typically arises at the

A

limbus

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17
Q

You take a scleral biopsy to see if the causes is inflammatory or neoplastic, what confirms that it is inflammatory

A

granulomatous inflammation

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18
Q

What are the 3 types of scleral inflammation

A

1) Diffuse episcleritis
2) Nodular scleritis
3) Nodular granulomatous episclerokeratitis (NGE)

all look very similar

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19
Q

How does diffuse episcleritis typically present *

A

“red eye”
rule out other causes of “red eye” (conjunctivitis, uveitis, glaucoma)

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20
Q

What are the clinical signs of diffuse episcleritis *

A

1) Diffuse episcleral injection (red eye) *
2) Little to no pain or ocular discharge
3) Usually no intraocular abnormalities
4) Peri-limbal corneal edema *
5) Normal or low intraocular pressure

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21
Q

What causes “red eye”

A

1) Episcleritis
2) Conjunctivitis
3) Uveitis
4) Glaucoma

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22
Q

What commonly causes episcleritis

A

think its immune mediated inflammation
-present in certain breeds

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23
Q

sub-conjunctival scleral swelling near limbus
adjacent peri-limbal edema
generally painful

A

nodular scleritis

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24
Q

T/F: episcleritis is typically painful

A

False

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25
Q

T/F: nodular scleritis is typically painful

A

True

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26
Q

nodular granulomatous episcleritis (NGE) is most commonly diagnosed in

A

Collies

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27
Q

T/F: nodular granulomatous episcleritis (NGE) is generally painful

A

True

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28
Q

Where is nodular scleritis seen

A

sub-conjunctival scleral swelling near limbus and adjacent peri-limbal edema

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29
Q

Where is nodular granulomatous episcleritis (NGE) seen

A

involves conjunctiva, sclera +/- adjacent cornea

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30
Q

What are differential diagnoses for nodular granulomatous episcleritis (NGE) and nodular scleritis

A

neoplasia

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31
Q

How do you treat scleral inflammatory disease

A

-Strongly consider referral
1) Topical dexamethasone 0.1% solution TID
2) Topical cyclosporing A 2% or tacrolimus 0.02% solution TID
if poor responses to topical
1) Oral prednisone 0.5-2mg/kg PO
2) Oral azothioprine
3) Subconjunctival steroids
4) Cryotherapy

Very likely to recur

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32
Q

Why do you need to refer scleral inflammatory diseases

A

because they are very likely to recur, some have to enucleate
Needs to be done right because steroids last 8 weeks in eye and if ulcer develops then it could get really bad

treatment looks like:
1) Topical dexamethasone 0.1% solution TID
2) Topical cyclosporin A 2% or tacrolimus 0.02% solution TID
if poor responses to topical
1) Oral prednisone 0.5-2mg/kg PO
2) Oral azothioprine
3) Subconjunctival steroids
4) Cryotherapy

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33
Q

What episcleral tumors typically occur in horses and cattles

A

Squamous cell carcinoma (SCC) - usually limbal

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34
Q

T/F: episcleral tumors are common in cats

A

False- rare in cats

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35
Q

What is most common episcleral tumors in dog

A

1) Epibulbar melanoma - hard to remove, can lead to glaucoma (block drainage angle at limbus)
2) Hemangiosarcoma

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36
Q

What is the biggest risk with older dogs with epibulbar melanoma

A

to can lead to glaucoma by blocking the drainage angle at the limbus

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37
Q

epibulbar melanoma in young dogs is typically

A

very aggressive locally to eye and metastasize
typically enucleate the eye

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38
Q

epibulbar melanoma in old dogs is typically

A

slow to grow and doesn’t metastasize
might block drainage angle at the limbus leading to glaucoma

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39
Q

How many layers are in the cornea

A

1) Tear film *
2) Epithelium (5-7 layers, water tight, prevents drugs from entering, lipophilic, strong turnover 24 hours period replaced)
3) Stroma (strong collagen later, perfect arrangement)
4) Descemet’s membrane
5) Endothelium

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40
Q

What is the function of the cornea tear fim

A

-Smooth ocular surface
-oxygen and nutrients
-removes waste
-optical transparency
-immunologic functions

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41
Q

5-7 layers, water tight, prevents drugs from entering, lipophilic, strong turnover 24 hours period replaced

A

corneal epithelium

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42
Q

layer of cornea:
75% water, 25% collagen
loves fluorescein
relatively acellular
keratocyte primary cell type
takes longer to repair

A

stroma

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43
Q

What layer of the cornea does fluorescein bind to

A

Stroma

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44
Q

What is the primary cell type of the stroma

A

keratocyte

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45
Q

layer of the cornea that dehydrates stroma aqeuous humor by pumping mechanism
non-regenerative

A

Endothelium

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46
Q

T/F: cornea endothelium is regenerative

A

False- neighboring cells hypertrophy but eventually cant keep up

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47
Q

What does the cornea not have

A

-Blood vessels
-Epithelial pigment
-Keratinization
-Lymphoid tissue

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48
Q

precise collagen arrangement
relatively acellular
relatively dehydrated

A

cornea

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49
Q

What innervates the cornea

A

CN V (trigeminal) - ophthalmic branch

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50
Q

What dog breeds have decreased innervation compared to others

A

brachycephalic dogs

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51
Q

why are superficial corneal ulcers very painful

A

cornea - by CN V (trigeminal)
more nerve endings (unsheathed) in epithelium/superficial cornea so it is very painful

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52
Q

Where is there a higher nerve density in the cornea

A

at the center superficially

Dolicocephalic > Brachycephalic

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53
Q

Are superficial or deep corneal ulcers more painful

A

Superficial

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54
Q

any stimulation of corneal nerves =

A

reflex stimulation of CN V nerve branches to anterior uveal tract
leading to reflex uveitis with painful ciliary body muscle spasm

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55
Q

Reflex uveitis

A

occurs when cornea is stimulated in all cases of keratitis
stimulation of CN V leads to reflex uveitis with painful ciliary body muscle spasm
more severe keratitis = more severe uveitis

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56
Q

How do you relieve painful ciliary body muscle spasms from reflex uveitis?

A

Cycoplegic drugs such as atropine
(mydriatic)

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57
Q

How do epithelial wounds heal

A

stem cells turnover rapidly to fill in defect
doesnt need help from other sources
sound happen in days

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58
Q

How do stromal wounds heals

A

not just regenerating cells
rebuilding collagen and arranging in different order to become see through again
-complex process that takes a lot of time

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59
Q

Characteristics of corneal epithelial wound healing

A

1) Epithelial cells lose adheasion to basement membrane
2) Mitosis with increased cell numbers and activation of limbal stem cells
3) Migration of cells until defect close
4) Re-establishment of basement membrane adhesion

very quick- within 24 hours when you arent filling in a defect

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60
Q

happens quickly
minimal fibrosis hence minimal loss of transparency
no treatment currently available to speed epitheliazation

A

corneal epithelial healing

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61
Q

Characteristic of corneal stromal wound healing

A

-Happens slowly
-Requires activation, transformation and migration of keratocytes into fibroblasts
-May require vascularization
-fibrosis initially, follwed by new collagen synthesis
-epithelization often precedes resolution of stromal remodeling

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62
Q

How do you treat corneal epithelial wound

A

no treatment currently available to speed epithelialization
just give it time (5-7 days) and prevent infection

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63
Q

corneal facet

A

when there is still a divot in the cornea but epithelial cells have covered the healing stroma (which hasn’t caught up to the epithelial cells)
-Does not take up stain

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64
Q

T/F: corneal facets do not take up stain

A

True

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65
Q

All corneal disease can be simplified to which two pathologic states

A

1) Loss of transparency
2) Loss of thickness (corneal ulceration)

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66
Q

What layers of the cornea are hydrophilic

A

stroma- loves fluorescein sodium and bind immediately

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67
Q

What layers of the cornea are hydrophobic

A

epithelium
descemet’s membrane

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68
Q

How do you diagnose corneal ulcers

A

Fluorescein sodium binding to the stroma

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69
Q

What are the different kinds of corneal ulcers *

A

1) Simple: Superficial, Not infected, heal in appropriate amount of time, no complicating factors

2) Complicated: deep (loss of stroma), infected/melting, complicating factors present, slow to heal

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70
Q

What are the 4 criteria of a simple corneal ulcer

A

1) Superficial - curvature intact

2) Not infected - no cellular infiltrate, no organisms on cytology, negative culture and sensitivity, no concurrent keratomalacia (corneal melting), no stromal loss

3) Heal in appropriate amount of time: 5-7 days

4) No Complicating factors

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71
Q

How do you tell a corneal ulcer isnt superficial

A

loss of corneal curvature

72
Q

How do you tell a corneal ulcer isnt infected

A

-no cellular infiltrate (opacity)
-no organisms on cytology (very important)
-negative culture and sensitivity
-no concurrent keratomalacia (corneal melting)
-no stromal loss
-no other concurrent signs: conjunctival hyperemia, episcleral injection, degree of reflex uveitis, constricted pupil

73
Q

What is the normal canine cornea healing time

A

Should be healed in 5-7 days
-epithelial defects alone heal faster than those involving stromal defects

any delay in wound healing = complication

74
Q

What are complicating factors in corneal ulcers that may contribute to non-healing *

A

-Entropion
-KCS
-Eyelid tumors
-Lagophthalmos
-Ectopic cilia
-Trigeminal neuropathy
-Systemic disease (ie Cushings, diabetes mellitus)
-Distichiasis

75
Q

How do you treat superficial ulcers **

A

You arent making the ulcer heal

1) Broad spectrum topical antibiotic TID
Dog: Triple antibiotic ideal (Neomycin Polymixin B _ Bacitracin/ Gramicidin)
Cat: Erythromycin or Tobramycin

2) Analgesia (3-5 days)
Oral NSAID (never topical) or Gabapentic
Topic Atropine

3) E-collar if necessary to prevent self-trauma

recheck 5-7 days for normal dogs, 203 days for brachycephalic dogs

76
Q

What would the cytology of an infected ulcer look like

A

neutrophils, intracellular and extracellular bacteria, fungus, etc

77
Q

T/F: you should use a topical NSAID to heal a corneal ulcer

A

False- it delays healing and not analgesia- no prostaglandin receptors in cornea)

use an oral NSAID instead (wont do this)

78
Q

Why should you never use topical NSAID to heal a corneal ulcer

A

1) Delays healing
2) Not analgesic: no prostaglandin receptors in cornea

79
Q

When do you recheck superficial corneal ulcers

A

Normal dogs 5-7 days

Brachcephalic dogs 2-3 days

80
Q

Prolonged properacaine is toxic to the

A

epithelium - not a treatment tool
only a diagnostic tool
will delay corneal healing

81
Q

Why do you need to recheck brachycephalic breeds with corneal ulcers in 2-3 days while other dogs are 5-7 days?

A

-Decreased corneal sensation
-Lagophthalmos
-evaporative keratitis (from not blinking)
-Increased incidence of KCS

*More likely to experience complications in corneal healing

82
Q

incomplete or abnormal closure of the eyelids

A

Lagophthalmos

83
Q

with corneal perforations, what fills in the gap

A

fibrin plug - prevent aqeuous humor from leaking out

84
Q

Why do cornea’s melt?

A

bacterial +fungal infections (Pneumonas and Aspergillus)
chew through collagen and
Neutrophil

85
Q

If corneal stromal loss is >50% of corneal thickness or cornea is perforation, what should you do

A

refer for surgical grafting procedure (synthetic graft or conjunctival graft)

cases with additional complicating factors likely warrant sooner referral

86
Q

What is an immediate side effect of synthetic graft or conjunctival graft

A

blinded that eye with graft material

87
Q

synthetic graft or conjunctival graft

A

used for corneal stromal loss that is >50% of corneal thickness or perforated cornea

after months of healing, graft material is trimmed off, might be able to see around eye

88
Q

How do you rule out a complicated corneal ulcer? *

A

Cytology is most rapid and economic
1) Topical proparacaine
2) Two slides- one for pathologist or gramstain, one for you
3) Microbrush dental applicator or cytobrish or handle-end of scalpel blade

89
Q

With complicated ulcers, what are the downsides of culture and sensitivity

A

they will take 48 hours

90
Q

Upon cytology of a complicated corneal ulcer you see bacteria, what should you do next

A

Topical anti-microbial q2-6h (big guns- cidal drugs)
-Ofloxacin (mostly G- but broad fluoroquinolone)
-Cephalexin (G+)
Added together
+/- Voriconazole 0.3% (antifungal)
+/- oral antibiotic, Clavamox

Control any secondary uveitis- topical atropine 1% solution q8-24h and oral NSAIDs

Provide analgesia if painful: oral gabapentin

Ecollar

91
Q

For complicated ulcers being treated with antimicrobials, how often do you need to give them

A

q2-6 hours- much more often

92
Q

Topical 2nd gen fluroquinolone that mainly has gram negative coverage but is a big gun in treatin complicated infected corneal ulcers

A

Ofloxacin 0.3%

93
Q

Topical cephalosporin that mainly has gram + coverage, added with other antimicrobials for treated complicated corneal ulcers

A

Cephalexin

94
Q

What anti-fungal should you use to add to treat fungal corneal ulcers or added on when treating horses

A

Voriconazole 0.3% - best corneal penetration

95
Q

In complicated ulcers, how do you control for secondary uveitis

A

-Topical atropine 1% solution q8-24h
(Cats- try to use ointment or they will foam at the mouth)
-Oral NSAIDs

96
Q

What is a good oral antibiotic added with topical antibiotics for complicated infected corneal ulcers in dogs

A

Clavamox

97
Q

In complicated corneal ulcers, what should you do for analgesia

A

oral gabapentin when paired with NSAID

98
Q

How do you treat corneal malacia *

A

topical anti-collagenase / anti-protease q1-6h
1) Autologous / heterologous serum
-Red top tube, draw off serum and give to client
2) Tetracycline- oxytetracycline ointment / Doxycycline 5mg/kg PO q12h
3) EDTA solution- fill half of a purple top tube with saline, can dispense in dropper bottle for ease of administration

99
Q

What are the 4-5A’s of complicated corneal ulcer therapy in dogs and cats *

A

1) Antibiotic- topical
2) Anti-collagenase/protease -topical (serum/EDTA)
3) Atropine - topical
4) Antibiotic- oral
5) Anti-inflammatory - oral

100
Q

What are the 4-5 A’s of complicated corneal ulcer therapy in horses *****

A

1) Antibiotic- topical
2) Anti-fungal- topical
3) Anti-collagenase/protease - topical
4) Atropine - topical
5) Anti-inflammatory

they dont need oral antibiotics but do need topical antifungals

101
Q

Should you do a tarsorrhaphy for complicated ulcer with stromal loss?

A

No - you cant track the progress

102
Q

How do you administer eye medication into the horse *

A

Subpalpebral lavage tube

103
Q

Subpalpebral lavage tube

A

used in cases of corneal damage, stromal abscess
allows you to put in solutions frequently of anti-fungal and antimicrobials
DO not push air into the tube

104
Q

are aminoglycosides cidal or static

A

cidal but not good spectrum of activity
used as little guns
-Gentamycin
-Tobramycin

105
Q

Gentamicin and Tobramycin are ______

A

fluoroquinolones (cidal) but not good spectrum
little guns

106
Q

What is a common topical cephalopsporin used as good gram + coverage

A

Cefazolin

107
Q

What is one downside in using topical cephalosporings

A

they dont penetrate an intact epithelium

108
Q

What are different fluoroquinoloes used to treat ulcerative corneal disease

A

Ciprofloxacin (very painful)
Ofloxacin
Moxifloxacin

109
Q

With any type of ulcer, what should you absolutely not give

A

1) Steroids
2) NO topical NSAIDs

prevent
-epithelial healing
-leukocyte migration
-collagen formation
-corneal vascularization

Increase effects of collagenases
Suppresses immune system

110
Q

For corneal ulcers, why should you not give steroids or topical NSAIDs

A

they prevent
-epithelial healing
-leukocyte migration
-collagen formation
-corneal vascularization

Increase effects of collagenases
Suppresses immune system

111
Q

you have a young dog with recurrent ulceration in the dorsal central cornea, what might be happening

A

ectopic cilia

112
Q

What are canine indolent corneal ulcers *

A

Superficial, loose, non-adherent epithelial flaps (looks like you can w

non healing superficial ulcers that are present for weeks to months

No evidence of infection

Careful exam and rule out other causes (entropion, ectopic cilia, etc)

113
Q

What systemic diseases might cause healing corneal ulcers

A

Cushings (esp horses)
Diabetes

114
Q

What is the pathogenesis of indolent ulcers *

A

Failure of normal cell-cell adhesion between the epithelium and its basement membrane and underlying stroma

115
Q

How do you treat indolent ulcers *

A

grid keratomy or diamond burr debridement

opens up the new stroma that promotes healthy cell to cell adhesion complex formation

116
Q

Grid Keratomy and Diamond Burr debridement is for

A

Treatment of indolent ulcers
opens up the new stroma that promotes healthy cell to cell adhesion complex formation

Never for complicated ulcers or cats

117
Q

You should never do Keratomy and Diamond Burr debridement if

A

1) Complicated ulcers: infection, melting, stromal losses - will just drive the infection deeper down (do cytology to rule out infection first)

2) Cats - most common cause of indolent ulcers if FHV-1

118
Q

How do you prepare for Keratomy and Diamond Burr debridement

A

good restraint
topical anesthesia (proparacaine)
dilute betadine rinse to clean corneal surface
cotton tip applicators- do not have to be sterile
25g needed
dry q-tips

Cotton tip: debride all loose epthelium with dry cotton tip applicator - move 360 limbus to limbus all the way around

Grid keratotomy: superficial lines across ulcer bed. 1mm of healthy cornea on either side of ulcer bed

Diamond burr debridement: rotating 3.5mm burr, creates fine abrasions in anterior stroma similar to grid keratomy
very safe and easy to perform
placement of bandage contact lens

119
Q

rotating 3.5mm burr, creates fine abrasions in anterior stroma similar to grid keratomy
very safe and easy to perform
then place bandage contact lens
treatment for indolent ulcers

A

diamond burr debridement

120
Q

superficial lines across ulcer bed. 1mm of healthy cornea on either side of ulcer bed
treatment for indolent ulcers

A

grid keratomy

121
Q

After doing Keratomy and Diamond Burr debridement, what should be done afterwards

A

-Ecollar
-Atropine 1% solution q24h for reflex uveitis
-Broad spectrium antibiotics- Terramycin or tetracyclines
-Analgesia: Oral NSAID for 5-7 days and oral gabapentin for 3-5 days

122
Q

What is the most common cause of corneal ulcers in cats *

A

Feline herpesvirus -1

123
Q

What is classic sign of FHV-1

A

dendritic ulcers

124
Q

How do you treat FHV-1 *

A

1) Topical antiviral:
Cidofovir 0.5% solution BID x 2-3weeks *
Idoxuridine
Trifluridine
2) Systemic antiviral therapy (if URT)
Famciclovir 40mg/kg PO TID
3) L-lysine
4) Minimize stress

125
Q

What systemic anti-viral is fatal to cats

A

Acyclovir

126
Q

What does a white cornea indicate

A

1) Corneal dystrophy
2) Corneal degeneration
3) Fibrosis
4) Descemet’s striae
5) Keratic precipitates

127
Q

white corneal opacity
bilateral
purebreds
non-painful
non-progressive
needs no treatment
does not interfere with vision
Metabolic deposits of lipid or calcium

A

Corneal Dystrophy

128
Q

white corneal opacity
unilateral or bilateral
usually asymmetric
associated with concurrent ocular surface or intraocular disease
systemic implications: hypoT4, hyperlipidemia
vascularization frequent finding
often associated with ulceration of overlying epithelium
most commonly calcium deposits

A

Corneal degeneration

129
Q

what is a frequent finding of corneal degeneration

A

vascularization

130
Q

What causes corneal degeneration

A

associated with concurrent ocular surface or intraocular disease
systemic implications: hypoT4, hyperlipidemia
vascularization frequent finding
often associated with ulceration of overlying epithelium
most commonly calcium deposits

131
Q

How do you treat corneal degeneration

A

1) Identify any concurrent ocular or systemic diseases and treat (ie KCS, HypoT4, hyperlipidemia)
2) Will typically scrap calcium out
3) EDTA helps

Strongly consider referral (or at least send some photos to your favorite ophthalmologist and discuss case)

fair to guarded prognosis based on stability of epithelium

132
Q

white corneal opacity for disorganized collagen
associated with previous corneal ulcer/keratitis
may also be associated with vascularization and pigmentation
Non painful (follows healing of corneal disease)
variable effect on vision depending on size
does not need treatment

A

Corneal fibrosis

133
Q

Is corneal fibrosis painful?

A

No

134
Q

Do you treat corneal fibrosis?

A

No

135
Q

What might be causing a brown corneal opacity

A

1) pigement
2) neoplasia (melanoma)
3) sequestrum
4) iris prolapse
5) foreign body
6) dermoid

136
Q

What might be causing a yellow corneal opacity

A

stromal infiltrate / WBCs

137
Q

What does a blue corneal opacity mean *

A

Edema
-epithelium is a natural barrier to edema
-endothelium barrier and active pump

Focal edema = epithelial disease
generalized edema = endothelial disease

138
Q

focal corneal edema means there is an ________ *

A

epithelial disease

139
Q

generalized corneal edema means there is an _______ *

A

endothelial disease

pumps degenerate and cant pump out

140
Q

what disease in dogs can cause bilateral cornea edema

A

distemper

141
Q

What are your differentials for focal cornea edema *

A

1) Ulcerative keratitis- corneal laceration or perforation
2) Non-ulcerative keratitis
3) Keratic precipitates
4) Anterior lens luxation

142
Q

What are your differentials for diffuse cornea edema

A

1) Glaucoma
2) Anterior uveitis
3) Endophthalmitis
4) Endothelial dystrophy
5) Senile endothelial degeneration
6) Immune memdiated endothelitis
7) Blue-eye (CAV) -rare

143
Q

What breeds get endothelial dystrophy leading to diffuse corneal edema

A

Boston terriers
Dachshund
Chihuahuas
Basset hounds

144
Q

Endothelial dystrophy

A

diffuse corneal edema due to loss of endothelium leading to vision loss
common in
Boston terriers
Dachshund
Chihuahuas
Basset hounds

145
Q

How do you treat corneal edema *

A

depends on cause
tx primary cause (ulcerative keratitis, non-ulcerative keratitis, keratic precipitates, anterior lens luxation, glaucoma, anterior uveitis, endophthalmitis)

1) Topic hyperosmotics - 5% saline (ointment more efficacious than solution)
TID to QID
2) Thermokeratoplasty: burn marks into stroma- edema is lost

146
Q

What causes red corneal opacities *

A

blood vessels

147
Q

almost all red corneal opacities are

A

vascularization of the cornea

148
Q

Vascularization of the cornea is a

A

common and non-sepcific response to variety of insults

149
Q

corneal vascularization with corneal ulcers

A

simple ulcers are not generally associated with vascularization

ulcers involving stromal loss frequently heal by vascularizations

150
Q

With corneal ulcers when do you see corneal vascularization

A

ulcers involving stromal loss frequently heal by vascularizations

151
Q

T/F: indolent ulcers have variable vascularization

A

true - more chronic = more vessels

152
Q

Where do the corneal blood vessels come from

A

superficial: conjunctiva (cross limbus)

deep: uveal tract: wont see them cross limbus

153
Q

What do superficial corneal vessels look like *

A

branch like trees/ hedge (typically 360 degrees around)

154
Q

What do deep corneal vessels look like

A

dense like hedge
show there is deep corneal or intraocular disease present

155
Q

What diseases are associated with superficial corneal vascularization

A

KCS/Dry eye

diagnose via schirmer tear test
corneal transparency may imrpove with treatment

all red eyes and all eyes with discharge need a STT

156
Q

What is another name for pannus

A

Chronic Superficial Keratitis (CSK)

157
Q

What causes Chronic Superficial Keratitis (CSK)
or pannus *

A

immune mediated (lymphoplasmacytic) corneal disease of german shephards, shepherd mixes and sighthoud mixes

non-painful, progressive, exacerbated by exposure to UV light

158
Q

What breeds get Pannus or Chronic Superficial Keratitis (CSK)

A

German Shepherds
Shepherd mixes
sighhound mixes

159
Q

What are the clinical signs of Chronic Superficial Keratitis (CSK)

A

-Superficial vascularization
-Pigmentation
-Corneal degeneration
-Fibrosis

160
Q

what type of inflammation is seen with Chronic Superficial Keratitis (CSK)

A

lymphocytic plasmocytic inflammation

161
Q

Where does Chronic Superficial Keratitis (CSK) typically begin

A

temporal limbus can progress to blindness

162
Q

is Chronic Superficial Keratitis (CSK) unilateral or bilateral

A

bilateral but not always symmetric

163
Q

How do you treat Chronic Superficial Keratitis (CSK) “pannus” *

A

1) Topical dexamethasone 0.1% or topical 1% prednisolone acetate solution BID to QID
-Initial tx until CsA or Tacro start working

2) Topical cyclosporin A 0.2% ointment or tacrolimus (better for pigment)
-take 6-8 weeks to reach therapeutic levels in the cornea

3) Goggles to decrease exposure to UV light

Recheck in 2 months and slow taper of medications once disease is controlled

Treatment is lifelong- disease is. controlled not cured

164
Q

In treating Chronic Superficial Keratitis (CSK), is cyclosporin or tacrolimus better for getting rid of pigment

A

Tacrolimus

165
Q

thickening of the third eyelid associated with immune mediated inflammation

A

Plasmoma (atypical pannus)

166
Q

What diseases are associated with corneal vascularization

A

1) Ulcerative keratitis/ lacerations/ performations
2) KCS
3) Intraocular disease (uveitis, glaucoma)
4) Pannus / CSK
5) Episclerokeratitis/ nodular episcleritis / nodular fasciitis
6) Neoplasia
7) Eosinophilic keratitis

167
Q

What breed gets pigmentary keratopathy *

A

pugs - likely genetic disease
80% of pugs are affected to some degree

treatment: prevent pigment from covering entire cornea or it can lead to blindless

168
Q

Pigmentary keratopathy in the pug is typically bialteral or unilateral

A

bilateral - not always symmetrical but starts with the medial pigment

169
Q

How does Pigmentary keratopathy in the pug progress *

A

starts medially and progresses laterally often lateral

often has superficial vascularization associated with areas of pigmentation

170
Q

How do you medically manage Pigmentary keratopathy in the pug *

A

-Treat any associated KCS
-Immunomodulation
Cyclosproing A and Tacrolimus (better for pigment)
-Topical steroids may help but are dangerous in at-risk brachycephalic corneas
-Lubricants may help with exposure keratopathy and protect cornea from any associated entropion

Treatment will be lifelong

171
Q

necrotic corneal stroma giving brown corneal opacity in cats

A

feline sequestrum

tx: surgical resection

172
Q

Limbal melanoma is more aggressive in __________ and slower progression in ________

A

aggressive: young dogs
slower: older dogs

173
Q

How might cats get feline corneal sequestrum

A

brachycephalic cats predisposed
chronic ocular irritation (tear film abnormalities, entropion, FHV-1)

174
Q

How do you treat feline corneal sequestrum

A

if <50% remove lesion
if >50% grafting procedure
-conjunctival graft
-slding corneal-conjunctival transposition

175
Q

Pannus and Pigmentary keratopathy in the pug are

A

life long treatments

Ophthalmology (7 decks)

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