1 - 2 Optho Flashcards
1
Q
Aqueous humor delivers
A
Glucose , amino acids, vitamins and other nutrients to the cornea
2
Q
What relievers oxygen to the cornea
A
Tears
3
Q
When you are asleep or eyes closed, what is delivering oxygen to the cornea
A
Palpebral conjuctivial vessels
4
Q
What type of epithelium helps cornea maintain clarity
A
Non keratinezed
5
Q
Causes of edema
A
Glaucoma, ulceration, uveitis, endothelial dystrophy and lens luxation
6
Q
Edema
A
Damage to endothelium or loss of epithelium
7
Q
Why does corneal ulceration cause edema
A
Missing epithelium cannot keep tears out so they enter teh stroma in the area of the ulcer
8
Q
Dense , widespread corneal edema is usually due to
A
Endothelial disease
9
Q
Cellular infiltration
A
Immune mediated, neoplasia, and WBC can enter the cornea via tears and limbus with ulcers
10
Q
Scar formation - fibrosis
A
Caused by abnormal arrangement of collagen fibers
11
Q
What may lead to faster scar resolution
A
Topical corticosteroids
12
Q
Pigmentation can occur with
A
Chronic irritation , active or inactive
13
Q
Corneal vessels grow
A
1 - 2 mm per day
14
Q
Vascularizaiton takes how long to get started
A
A week
15
Q
Vascularization is indicative of
A
Active chronic disease
16
Q
When the cornea is injured or inflamed, it recruits vessels from
A
An arcade of limbal vessels to help meet the needs
17
Q
Superficial vessels develop in response to
A
Superficial keratitis
18
Q
Deeper vessels develop in response to
A
Deep corneal disease or intraocular disease such as uveitis and glaucoma
19
Q
Superficial vessels are
A
Solitary, that branch dichotomously and extend far into the cornea
20
Q
Deep vessels form
A
Brush border with short straight vessels densely packed together - do not make it to the center of the cornea
21
Q
What are ghost vessels
A
Keratitis resolves and the corneas need for blood supply diminished
22
Q
Keratinization is most common with
A
Keratoconjuctivitis Wicca
23
Q
When the epithelium lacks moisture what could occur
A
Keratinization
24
Q
Secondary uveitis results from
A
Axonal nerve reflex in the trigeminal nerve and is referred to a reflex uveitis
25
Anterior uveitis refers to
Inflammation of the iris and ciliary body
26
Axonal reflex mechanism causes signs of anterior uveitis such as
Protein and cellular leakage from uveal blood vessels, ciliary spasm and miosis
27
Which ophthalmic medication is safer if ocular integrity is questionable
Solutions
28
Is solutions or ointments longer contact time
Ointments
29
What can happen if ointments enter the globe
Severe uveitis
30
Topical opthalamic formulations can be made from
IV preparations
31
When are oral antibiotics indicated
Perforation or impending perforation, eyelid disease, nasolacrimal disease and vitreal infections
32
Triple antibiotics contain
Neomycin, poly mix in B and bacitracin
33
Neomycin
Aminoglycosides, bactericidal for gram + and -
34
Bacitracin or gram iced in
Bactericidal against gram +
35
Polymixin B
Bactericidal gram -
36
3 types of antibiotics
Neomycin, bacitracin, polymixin B
37
Aminoglycosides function
Basic spectrum is gram negative
38
Examples of aminoglycosides
Tobramycin and gentamicin
39
Chloramphenicol action
Basic spectrum is gram positive, gram negative, mycoplasma NOT pseudomonas
40
Which drug penetrates the intact epithelium better than most antibiotics
Chloramphenicol
41
Which AB do you worry about public health significance
Chloramphenicol
42
Cephalosporin action
Gram positive and negative spectrum
43
What happens to cephalosporin action with increasing generation
Gram positive spectrum decreases and gram negative spectrum increases
44
What is the efficacy of cephalosporins against pseudomonas
Low
45
Fluoroquionolones action
Broad gram negative and gram positive - mycoplasma and chlamydia
46
Fluoroquionoles should be reserved for
Severe infection
47
What two AB penetrate the intact epithelium better
Chloramphenicol and fluoroquionolones
48
Oxytetracycline action
Inhibits matrix metalloprotienases ,
49
Oxytetracycline may hasten healing of
Indolent ulcers
50
Serum contains
A macroglobulins and other substances
51
Serum’s a macroglobulins decrease
Matrix metalloprotienase activity which can stop ulcer progression
52
How long can you refrigerate serum
1 - 2 week
53
2 types of parasympatholytic drugs
Atropine and tropicamide
54
Atropine parasympatholytic drug is available in what forms
1% ophthalmic solution and ointment
55
Onset of action of atropine
1 - 2 hours in normal eyes
56
Which is very bitter tasting
Atropine
57
Duration of action of atropine
Several days - weeks in normal eyes
58
What will cause atropine to take longer to act
Uveitis
59
When should you avoid atropine
When glaucoma is present
60
Atropine can cause decreased
Tear production
61
Main action of atropine
Paralyze the ciliary muscle and iris sphincter - dilate the pupil and decreases pain
62
What form is tropicamide available in
1% ophthalmic solution
63
Onset for tropicamide
10 - 20 mins
64
Duration of tropicamide
6 - 12 hours
65
Why is tropicamide not working in uveitis
Weak compared to atropine
66
Proparacaine
Topical anesthetic agent
67
When does proparacine begin to work
Immediately and last 20 mins
68
Proparacaine takes longer to act in
Horses
69
Artificial tear substitutes
Drops, gels, hyaluronate drops, artificial tear ointment
70
Corneal ulceration
Lesion of the cornea that is a result of the loss of the corneal epithelium
71
4 things to access ulcer for
Etiology, depth, (infection nor matrix metalloproteinases), rate of progression
72
Blepharospasm
Squinting
73
2 sources of pain fromm corneal ulcers
Cornea and the ciliary body
74
Epiphora
Excessive tearing
75
Tears are produced by
Main lacrimal gland and gland of the third eyelid
76
Tears are drained by
Nasolacrimal duct
77
Main DX for ulcers stain
Fluorecein stain
78
Why is fluorescein taken up by the stroma
Hydrophilic
79
Why is fluroscein stain not taken up by descendent membrane and epithelium
Lipophilic
80
6 causes of corneal ulcers
Trauma, eyelash abnormalities, eyelid abnormalities, foreign bodies, KCS, indolent ulcers
81
What is shape of ulcer when caused by trauma
Jagged
82
Ectopic cilia
Cilia originating from tarsal gland that emanates from palpebral conjuctiva
83
How do you look at ectopic Cilicia
4 mm in from eyelid margin
84
Where is ectopic cilia usually found in
12 o clock on the upper lid
85
Treatment of ectopic cilia q
Excise from conjuctiva using a derm punch
86
Entropion
Turning of eyelid margin that results in hair rubbing the cornea
87
Entropion can be
Conformational, spastic, or cicatricial
88
Treatment for Entropion
Modified Holz Celsus
89
The outside layer of cornea is
Non keratinized squamous epithelium
90
The epithelial turnover is
Every 7 days
91
What are the three layer of the epithelium of cornea
Basal cell, wing cells, squamous cells
92
Basal cell layer of epithelium
Deepest layer, single cell thickness,
93
What is the only epithelial. Layer to undergo mitosis
Basal cells
94
Wing cells
Middle transitional layer between basal and squamous cells
95
Wing cells are how thick
2 - 3 cells thick in dogs
96
Squamous cells
Anterior layer that is 2 -3 cells thick in dogs
97
What is on the surface on squamous cells
Microplicae and microvilli
98
Stroma makes up what % of corneal thickness
90%
99
the stroma is primarily
Collagen and GAGs
100
The endothelium
Inner most layer of the cornea with its basement membrane
101
The collagen of the stroma is formed from
Keratocytes - modified fibroblast
102
The proliferative potential of endothelium is
Very low
103
The endothelium is a single layer of
Hexagonal cell
104
The endothelium is importantly in maintains a state of
Relative dehydration of cornea
105
Thickness of the cornea
0.5 - 0.6 mm
106
How thick is the cornea in horses
1 mm
107
Limbus
Edge of cornea meets the conjuctiva and the sclera
108
When blood vessels invade the cornea they begin from the
Limbus
109
Corneal innervation is via the
Ophthalmic division of trigeminal nerve
110
Which is more painful, superficial or deep injury
Superficial
111
Functions of the cornea
Support intraocular contents, transmits light, refracts light
112
How does collagen fibril help maintain clarity
Highly organized and allow 99% of the light to pass through without scatter
113
What remove and prevent fluid influx in the cornea
Na and K ATP pump
114
The normal cornea is dehydrated, hydrated
Dehydrated
115
Cornea contains what % water by weight
70
116
Tear film
Prevents keratinization and washes away transient bacteria o numbers stay in check
117
What is the first stage of healing with epithelial detects
Basal cells
118
An entire healthy cornea can reepitheliazlie in
4 - 7 days
119
How does ciliary body spasm occur
Axons of the ophthalmic branch of teh trigeminal nerve send branches into the uveal tissue, where release neurotransmitter
120
Ectopic cilia originate from
Tarsal gland
121
Entropion
Tuning of eyelid margin that result in hairs rubbing the cornea
122
3 types of Entropion
Conformational, spastic, and cicatricial
123
Conformational Entropion is due to
Disproportionate size or orbit and globe position
124
Involutional
Acquired conformational Entropion that occurs secondary to loss of orbital tissue
125
Involutional is most common in
Geriatric cats
126
Spastic Entropion occurs
Secondary to ocular pain
127
Spastic Entropion can correct with
Topical anesthesia
128
Cicatricial Entropion
Occurs when chronically spastic tissue scares and rolls in or scar formation from traum causes lid to roll
129
How do you treat puppy Entropion
Vertical mattress sutures on lid
