Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Year 1/2 > Cognition & Senses 2: Cornea > Flashcards

Cognition & Senses 2: Cornea Flashcards

1
Q

name RED & BLACK circles?

what’s BETWEEN them?

A

RED = LENS

BLACK = CORNEA

BETWEEN = ANTERIOR CHAMBER filled with AQUEOUS HUMOR

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

what is the FUNCTION of the cornea? (2)

A
  1. REFRACT LIGHT = capture IMAGE on the RETINA & send it to the BRAIN via OPTIC NERVE
  2. BARRIER to MICROORGANISMS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

the CORNEA is MOSTLY MADE OF ____ ARRANGED ____

blood vessels?

how THICK is it?

A

REGULARLY ARRANGED COLLAGEN

MOSTLY AVASCULAR

it’s ~0.65 mm THICK

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

what NOURISHES the CORNEA?

A

nourishment = PRE-CORNEAL TEAR FILM & LIPIDS

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

what makes the cornea TRANSPARENT? (two)

A
  1. REGULARLY ARRANGED COLLAGEN with NO BLOOD VESSELS
  2. MOST DEHYDRATED STRUCTURE in body, so LIQUID FROM TEARS/AQUEOUS HUMOR PASSIVELY FLOWING IN will be PUMPED OUT BY Na/K pumps on the CORNEAL ENDOTHELIAL LAYER
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens if the Na/K ENDOTHELIAL pump in the CORNEA is DYSFUNCTIONAL?

A

FLUID OVERLOAD & CORNEAL EDEMA

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

ID what LESION this is & WHY

A

CORNEAL EDEMA

why? = the PUPIL & IRIS ARE OBSCURED, so we cannot see anything else, meaning that SOMETHING HAS COMPROMISED THE CORNEAL ENDOTHELIUM or EPITHELIUM

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

ID LESION & WHY

A

KERATITIS

why? = this is a result of BLOOD VESSELS & INFLAMMATORY INFILTRATES

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

ID LESION & LOCATION

what does it tell you in the DOG?

A

CORNEAL PIGMENT in the ANTERIOR CHAMBER

in the DOG, tells you CHRONIC CORNEAL INFLAMAMTION

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

ID LESION

tends to be present in ___-STAGE _____ DZ

A

CORNEAL MINERALIZATION (from LIPID or Ca)

tends to be present in END-STAGE CUSHING’S DZ

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

CORNEAL ENDOTHELIAL DECOMPENSATION…

= definition

3 appearance traits for eye?

A

= the CORNEAL ENDOTHELIAL CELLS DO NOT WORK, causing the Na/K PUMP to NOT WORK, causing DIFFUSE CORNEAL EDEMA

appearance?
1. DIFFUSE CORNEAL EDEMA ‘BLUE’
2. COBBLESTONE APPERANCE
3. CORNEAL THICKENING

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

ID DZ (3 words)

how can you tell what caused this?

A

CORNEAL ENDOTHELIAL DECOMPENSATION

AGE-RELATED CORNEAL DZ if it’s BLUE EYES that are BILATERALLY SYMMETRICAL

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

CAUSES of CORNEAL ENDOTHELIAL DZ…

primary? (2)
–>which one is MOST COMMON?
–> which one occurs in MIDDLE-AGED animals?

secondary? (1)
–> & give 2 examples

A

primary?
1. most commonly AGE-RELATED DEGENERATION of ENDOTHELIUM

  1. CORNEAL ENDOTHELIAL DYSTROPHY based on BREED, occurs in MIDDLE-AGED animals

secondary? = INTRAOCULAR DZ –> ex = uveitis or glaucoma

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

ID DZ

A

BILATERAL UVEITIS

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

AGE-RELATED ENDOTHELIAL DEGENERATION…

= occurs when…

onset?

painful?

unilateral vs. bilateral? why?

A

= occurs when ENDOTHELIAL CELL DENSITY DECREASES with AGE

usually SLOWLY PROGRESSIVE

often DOESN’T BECOME PAINFUL UNTIL LATE STAGES

ALWAYS BILATERAL because CORNEAL ENDOTHELIAL CELLS ARE THE SAME AGE IN BOTH EYES

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

CORNEAL ENDOTHELIAL DYSTROPHY…

= what is it?

3 predisposed breeds?

unilateral vs. bilateral? severity?

diagnosis? (three)

A

= IMPAIRED, ABNORMAL DEVELOPMENT of the CORNEA

3 breeds?
1. BOSTON
2. CHIHUAHUA
3. DACHSHUND

if YOUNGER ONSET, then UNILATERAL and EVENTUALLY BILATERAL —> ASYMMETRICAL SEVERITY IS COMMON

diagnosis?
1. CLINICAL SIGNS
–> DIFFUSE CORNEA that’s BLUE & THICKENED

  1. SIGNALMENT (breed?)
  2. RULE OUT UNDERLYING DZ (UVEITIS & GLAUCOMA)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ID DZ

A

CORNEAL ENDOTHELIAL DYSTROPHY

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

BULLOUS KERATOPATHY…

= definition

what 3 things can happen to the patient’s eyes as a result?

A

= when CORNEAL EDEMA is CHRONIC, and eventually forms BLISTERS or BULLA on the SURFACE OF THE EYE (cornea)

3 things…
1. the BULLA/blisters can RUPTURE & cause CORNEAL ULCERS
2. OCULAR PAIN
3. VISION IMPAIRMENT

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

ID DZ

A

ADVANCED, CHRONIC CORNEAL EDEMA causing BULLOUS KERATOPATHY

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

TREATMENT for CORNEAL EDEMA…

depends on…

we usually ONLY TREAT when…

medical tx? (1) how often?

A

depends on UNDERLYING DZ

we usually only treat when the edema is…
1. MARKED
2. or there’s PROGRESSIVE BULLA

medical tx?
= put MURO 128 (salt solution) on CORNEAL EPITHELIUM to PULL FLUID OUT OF THE EYE to REDUCE BLISTERS
–> BID to TID

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

RHO-KINASE INHIBITORS…

used normally for WHAT in people?

what can they do in dogs?

why is this not CLINICALLY very useful?

A

used normally to treat GLAUCOMA in people

in DOGS, can REPAIR or ENCOURAGE CORNEAL EPITHELIAL CELLS to IMPROVE FUNCTION in response to CORNEAL EDEMA

not very useful because only causes TRANSIENT relief

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

SURGICAL tx for CORNEAL EDEMA? (2)

prognosis?

helps to control ____ but DOES NOT help….

A

SURGICAL tx?
1. THERMOKERATOPLASTY = makes BURNS in cornea and TRIES TO ELIMINATE ULCERS

  1. GUNDERSEN FLAP = with a blade, remove ANTERIOR STROMA and CREATE A THIN MEMBRANE OF CONJUNCTIVA via a GRAFT to PULL OVER CORNEA

prognosis = GUARDED

helps to control PAIN but DOES NOT HELP VISION as TRANSPARENCY IS LOST

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

KERATITIS…

= definition

2 sub-categories?

what is a HALLMARK of this DZ?
–> is this always seen?

A

= CORNEAL INFLAMMATION

2 subs?
1. ULCERATIVE
2. NON-ULCERATIVE

VASCULARIZATION is a HALLMARK OF CORNEAL INFLAMMATION
–> NOT always seen GROSSLY bc vessels can be DEEP

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

DURATION & LESION?

A

CHRONIC KERATITIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
DURATION & LESION?
ACUTE KERATITIS
25
CORNEAL ULCER... aka? = definition? commonality?
aka ULCERATIVE KERATITIS = LOSS of CORNEAL EPITHELIUM +/- STROMA common in DOGS & CATS
26
ID LESION & potential DISEASE that caused it
LESION = CORNEAL ULCER (ulcerative keratitis) DZ = FHV-1 can cause this SPONTANEOUSLY
27
how can you tell if a corneal ulcer is SUPERFICIAL or DEEP?
SUPERFICIAL = ulcer is SMOOTH DEEP = ulcer is INDENTED
28
CAUSES of CORNEAL ULCERS...
1. EXTERNAL TRAUMA 2. TEAR FILM ABNORMALITIES 3. NEURON DAMAGE to CORNEA (CN V, OPHTHALMIC BRANCH) 4. INFECTION 5. EYELID DZ
29
what NEURON INNERVATES the CORNEA?
CN V, OPHTHALMIC BRANCH of TRIGEMINAL NERVE
30
CLINICAL SIGNS of CORNEAL ULCERS... (list five)
1. PAIN --> have EXPOSED CN V NERVE ENDINGS from REMOVED EPITHELIUM 2. INFLAMMATION 3. OCULAR DISCHARGE 4. EDEMA 5. STROMAL LOSS 'DIVOT'
31
IRIDOCYCLOSPASM... = definition causes WHAT 2 things? usually secondary to WHAT?
= when NERVE ENDINGS of CN V are AGITATED, causes SPASM of CILIARY BODY MUSCLE & IRIS MUSCLE causes... 1. PUPIL TO GET SMALL 2. OVERALL PAIN usually secondary to CORNEAL ULCER
32
ID LESION
CORNEAL ULCER also can see CORNEAL EDEMA & INFLAMMATION
33
if we can SEE BLOOD VESSELS in the eye with a CORNEAL ULCER, what does this indicate?
indicates that the ulcer is LIKELY CHRONIC
34
DESCEMETOCELE.. = definition what does this indicate?
= if a CORNEAL ULCER is DEEP ENOUGH, then HOLE IN THE CORNEA will be DEEP ENOUGH TO BASEMENT MEMBRANE or DESCEMET'S MEMBRANE this indicates that you're MINUTES AWAY FROM CORNEAL PERFORATION
35
ID LESION what does this mean??
DESCEMETOCELE this means THE CORNEA IS ABOUT TO PERFORATE!
36
once CORNEAL EPITHELIUM is DAMAGED, what disease is possible/how does it occur? what does the cornea LOOK LIKE? what are 2 common etiologic agents?
BACTERIAL INFECTION can occur when they COLONIZE ON STROMA prior to the EPITHELIUM HEALING CORNEA can look SOFT & MELTED 2 common agents? = SKIN FLORA 1. STREP 2. STAPH
37
ID DZ
CORNEAL INFECTION
38
DIAGNOSIS of CORNEAL ULCER? how does it work? what DZ would NOT STAIN even though it's a problem?
via POSITIVE FLUORESCIN DYE STAIN the CORNEAL STROMA will TAKE UP THE DYE because the STROMA is HYDROPHILIC, while if EPITHELIUM was intact it'd be HYDROPHOBIC (not take up any stain) a DESCEMETOCELE will NOT STAIN bc THE DESCEMET'S MEMBRANE IS ALSO HYDROPHOBIC
39
TREATMENT for CORNEAL ULCERS... depends on what 3 things? SUPERFICIAL ulcers (5)? DEEP ulcer treatment depends on... (3)
depends on... 1. DEPTH of the ULCER 2. INFECTION presence or not 3. APPROPRIATE HEALING RESPONSE from the cornea SUPERFICIAL ulcers? 1. give E-COLLAR 2. generally heal RAPIDLY by EPITHELIALIZATION in 5-7 DAYS 3. BROAD-SPECTRUM ANTIBIOTICS to PREVENT INFECTION TID 4. TOPICAL ATROPINE for PAIN 5. RECHECK in 1-WEEK DEEP ulcers tx depends on.. 1. treatment DEPENDS on HOW FAR AWAY THE NEWLY CREATED BLOOD VESSELS ARE from the ULCER (grows 1 mm/DAY) 2. CORNEAL INTEGRITY is COMPROMISED or not 3. INFECTION PRESENT
40
ATROPINE... why is it an IRIDOCYCLOPLEGIC drug? what will the PUPILS do? how does it work?
IRIDOCYCLOPLEGIC = stops the SPASMING of the CILIARY BODY, which is associated with IRITOCYCLOSPASM will cause the PUPILS TO DILATE how does it work? = PREVENTS spasm of ciliary body muscle & pupil muscle and STOPS PAIN
41
how should we ADMINISTER CORTICOSTEROIDS or NSAIDs for CORNEAL ULCERS? why? (2)
we should administer CORTICOSTEROIDS or NSAIDs ORALLY why? because if we do TOPICAL... 1. it can DELAY CORNEAL HEALING 2. and PREVENT COLLAGENASE ACTIVITY
42
INDOLENT CORNEAL ULCER... = definition etiology? commonality? 2 signalments? 2 clinical signs in EYE? (1 is +/-)
= SUPERFICIAL CORNEAL ULCER which FAILS TO HEAL IN APPROPRIATE TIME etiology? = usually due to UNDERLYING CORNEAL DEFECT with the BASEMENT MEMBRANE commonality? = COMMON IN DOGS 2 signalments? 1. GERIATRIC DOGS 2. BOXER BREEDS clinical signs in EYE? 1. VISIBLE LIPS of COREAL EPITHELIUM from it SLOUGHING OFF (lighter stain) 2. +/- BLOOD VESSELS in CORNEA
43
how do CORNEAL ULCERS usually heal?
need VASCULARIZATION & COLLAGEN DEPOSITION done by COLLAGENASES, which are produced by CORNEAL EPITHELIAL CELLS & NEUTROPHILS
44
TREATMENT for INDOLENT CORNEAL ULCER (SUPERFICIAL)? what is the TIME RANGE in which this should work? what TOOL do we usually use? prognosis? if this DOES NOT WORK, then do what?
tx = CORNEAL DEBRIDEMENT to REMOVE LOOSE EPITHELIAL EDGES & promote EPITHELIALIZATION/VASCULARIZATION this should work in 7-10 DAYS tool? = DIAMOND BURR prognosis = GENERALLY GOOD, MAJORITY HEAL if this DOES NOT WORK, then a BANDAGE CONTACT LENS can help KEEP EPITHELIUM ADHERED TO EYE & PROMOTE HEALING, but can also cause scarring
45
if we suspect an INFECTED CORNEAL ULCER, what DIAGNOSTIC should we do? what tx/frequency for SEVERE cases?
DIAGNOSTIC = C&S for ANTIBIOTIC PRESCRIPTION tx = FLUOROQUINOLONES if UNSURE ABOUT SAFETY OF PERFORMING CULTURE, can give EVERY 2 HOURS FOR SEVERE CASES
46
MAIN MEDICAL TREATMENT for CORNEAL ULCERS? --> what does it do? if NOT IMPROVING/GETTING WORSE after 48 hours, what should we consider?
MAIN MED = ANTI-COLLAGENASE, has SERUM that has NATURAL ANTIPROTEASE/ANTICOLLAGENASES to PREVENT CORNEA MELTING from ulcer if NOT IMPROVING or GETTING WORSE after 48 hours = SURGERY
47
SURGICAL REPAIR for CORNEAL ULCERS... usually done using ___ ____ 3 steps? 1 advantage? 1 disadvantage? we DO NOT perform this surgery UNLESS we believe...
usually done using CONJUNCTIVAL GRAFTS steps? 1. make LIP OF CORNEA 2. move it OFF SCLERA 3. flap up CONJUNCTIVAL GRAFT to MAKE A SEAL advantage = BRING BLOOD SUPPLY DIRECTLY TO AREA to cause HEALING and THICKENING OF CORNEA disadvantage = DECREASES TRANSPARENCY of CORNEA we DO NOT perform this surgery UNLESS we believe that WE CAN PRESERVE THE ANIMAL'S VISION
48
PANNUS aka? (3 words) common in WHAT BREED? what ENVIRONMENTAL FACTOR makes it WORSE? pain? what do we see on a FLUORESCIN STAIN?
aka CHRONIC SUPERFICIAL KERATITIS common in GSD exposure to UV LIGHT MAKES IT WORSE usually starts as NON-PAINFUL on FLUORESCIN STAIN, DOES NOT TAKE UP DYE
49
ID LESION (2 names) note: this lesion DID NOT TAKE UP FLUORESCIN STAIN
LESION = CHRONIC SUPERFICIAL KERATITIS or PANNUS
50
ID LESION (2 names)
PANNUS or CHRONIC SUPERFICIAL KERATITIS
51
ID LEFT AND RIGHT BUBBLE
LEFT = PANNUS or CHRONIC SUPERFICIAL KERATITIS RIGHT = PLASMOMA from ACCUMULATION OF PLASMA CELLS in CORNER OF EYE
52
3 STRONG SIGNS for PANNUS?
1. VENTROLATERAL PROGRESSIVE signs 2. BREED PREDILECTION (GSD) 3. NO FLUORESCIN DYE TAKE-UP
53
TREATMENT for PANNUS? medication & duration? frequency?
mostly TOPICAL CORTICOSTEROIDS like CALCINEURIN INHIBITORS for 4-6 WEEKS frequency can be up to 4 times DAILY initially, then try to reduce to TWICE DAILY
54
PROGNOSIS for PANNUS? if UNTREATED...
often MANAGED but NOT CURED, so OK if UNTREATED, can lead to BLINDNESS
55
PIGMENTARY KERATITIS>.. = definition 2 predisposed breeds? due to ____ _____ treatment options? (3)
= when MELANIN is DEPOSITED INTO CORNEA as a NON-SPECIFIC RESPONSE to CHRONIC, NON-ULCERATIVE CORNEAL INFLAMMATION 2 predisposed breeds? due to POOR CONFORMATION 1. PUGS 2. PEKINGESE treatment? 1. OCULAR LUBRICATION 2. CLOSE DOWN MEDIAL CANTHUS (to stop lagophthalmos) 3. TACROLIMUS
56
CORNEAL MINERALIZATION... = definition usually NON-____ DOGS vs. CATS? MOST COMMON presentation?--> how does it look? --> etiology? --> pain/tx?
= LIPID or CALCIUM DEPOSITION in CORNEA usually NON-ULCERATIVE DOGS > CATS most COMMON = CORNEAL DYSTROPHY --> milky WHITE, BILATERAL --> CONGENITAL --> NO PAIN/TX
57
ID LESION
CORNEAL MINERALIZATION
58
TRUE/FALSE CORNEAL DYSTROPHY causes an IRREVERSIBLE CHANGE to the cornea
TRUE
59
CORNEAL LIPIDOSIS.. appearance? (two) 2 causes? usually NON-___ reversible?
appearance? 1. WHITE, CRYSTALLINE LOOK 2. can be DIFFUSE or UNILATERAL causes? 1. TOPICAL CORTICOSTEROIDS 2. SYSTEMIC DZ usually NON-PAINFUL THIS IS REVERSIBLE
60
CORNEAL DEGENERATION... = definition potential signalment? appearance? tx? (3)
= result of CHRONIC CORNEAL DISEASE/ULCER, so even if it's FINISHED HEALING it DEPOSITS CALCIUM can potentially also be the result of GERIATRIC DOGS appearance = HAPHAZARD, WHITE CRYSTALLINE CHANGE tx? 1. TOPICAL LUBRICATION 2. TREAT CORNEAL ULCERS IF THEY OCCUR 3. use DIAMOND BURR to BREAK DOWN MINERALIZATION
61
if you see BLOOD VESSELS/INFLAMMATION with CORNEAL MINERALIZATION what medication SHOULD WE NOT USE/WHY?
we SHOULD NOT USE ANTI-INFLAMMATORIES because CALCIUM or LIPID will be MORE LIKELY TO SLOUGH OUT OF CORNEA
62
how does FELINE HERPESVIRUS cause CORNEAL ___? how LONG does it take for these to heal?
ULCERS the virus will LYSE CORNEAL EPITHELIAL CELLS & cause SUPERFICIAL CORNEAL ULCERS these ulcers can take MONTHS to heal
63
ID LESION & potential DZ
LESION = SUPERFICIAL CORNEAL ULCER DZ = FHV-1
64
TRUE/FALSE we can treat INDOLENT CORNEAL ULCER in the SAME WAY in a DOG and a CAT
FALSE, CATS need to have FHV-1 TREATED PRIMARILY, and CANNOT USE OTHER METHODS
65
2 CLINICAL SIGNS of FHV-1 in the CORNEA
1. DENDRITIC ULCERS in the CORNEA (breaks in epithelium) 2. GEOGRAPHIC/NON-HEALING ulcer
66
ID LESION & DZ
DENDRITIC CORNEAL ULCER likely FHV-1
67
STROMAL DZ.. = definition often caused by WHAT? treatment? --> MOSTLY? & 2 more! PROGNOSIS focuses on ____ rather than ____
= NON-ULCERATIVE KERATITIS that causes SCARRING, PAIN & IMMUNE-SUPPRESSION often caused by OCULAR FHV-1 treatment? --> MOSTLY supportive care! 1. TETRACYCLINE ANTIBIOTICS 2. ARTIFICIAL TEARS PROGNOSIS focuses on MANAGEMENT rather than CURE
68
ID DZ what should we expect on CYTOLOGY that's DIAGNOSTIC? painful? treatment? & duration? (2)
EOSINOPHILIC KERATITIS on CYTOLOGY, expect to see EOSINOPHILS, and EVEN ONE IS DIAGNOSTIC! USUALLY NOT PAINFUL treatment? 1. TOPICAL ANTIVIRALS usually LIFELONG 2. CORTICOSTEROIDS shorter term
69
CORNEAL SEQUESTRUM... = how does this occur IATROGENICALLY? give a breed PREDISPOSITION? (3 & overall)
IATROGENIC = if you DIAMOND BURR or DEBRIDE A CAT TOO VIOLENTLY with a NON-HEALING CORNEAL ULCER, causing a REGION OF NECROSIS breeds? 1. BRITISH SHORTHAIRS 2. BURMESE 3. PERSIANS --> overall, CATS WITH LAGOPHTHALMOS causing CHRONIC INFLAMMATION & NON-HEALING ULCERS
70
ID LESION
CORNEAL SEQUESTRUM

Year 1/2 (139 decks)

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