Ophthalmology Flashcards
(124 cards)
1
Q
Eyelid mass on dog - ddx - malignant or benign?
A
Benign usually.
Adenoma, adenocarcinoma, papilloma, benign melanoma
2
Q
Eyelid mass on cat - ddx - malignant or benign?
A
Malignant
SCC
3
Q
What are two approaches to treating entropion?
A
- Hotz Celsus sx
- Eyelid tacking
4
Q
A puppy presents with ectropion what is one easily implemented treatment?
A
Viscotears - lubrication
5
Q
What are two abnormal exit points of eyelashes?
A
- through meiobium gland (Distchia)
- through palpebral conjunctiva (Ectopic cilia)
6
Q
List 4 treatments for ectopic cilia
A
- plucking
- cryotherapy
- electrolysis
- transpalpebral resection
7
Q
what is trichiasis?
A
normal eyelash in a normal position but rubbing on the surface of the cornea
8
Q
What solution is suitable to clean a eyelid laceration?
A
Dilute betadine solution
not chlorhex or betadine scrub
9
Q
What is normal IOP?
A
12-24mmHg
10
Q
What does a hyper-reflective retina suggest?
A
thinning of the retina/degeneration or detachment
usu. chronic disease
11
Q
what does a hypo-reflective retina suggest?
A
oedema, sub-retinal effusion (retinal detachment), cellular infiltrate, fibrosis
Usu. acute disease
12
Q
How does a feline eyelid mass resection differ from a dog?
A
in dog - usu benign thus 1mm margin is appropriate.
in Cats - malignant - wide margins - eye enucleation
13
Q
What concentration of betadine solution can be used to flush the eye?
A
1:100
14
Q
What is ankyloblepharon?
A
delayed opening of eyelids in puppies or kittens (>10d).
Usu. secondary to infection.
15
Q
How do you treat ankyloblepharon?
A
Bathing lids w/ warm saline and gently prise open.
Flush saline and tx. infection.
16
Q
common cause of feline conjunctivitis
A
herpes
17
Q
common cause of feline chemosis
A
chlamydia
18
Q
common cause of canine conjunctivitis
A
allergic, FB, eyelid abnormality
19
Q
What topical ABs are used to treat a 2nd staph infection in dogs?
A
Chloramphenicol, fusidic acid, neomycin, polymxin
20
Q
name steroids used to treat follicular conjunctivitis
A
dexamethasone (Maxidex) potentiated prednisolone (predforte)
21
Q
name a topical steroid given TID to tx conjunctivitis in dogs
A
hydrocortisone
22
Q
List 3 drugs used to treat chlamydia in cats
A
Doxycycline
Azathioprine
Topical Chloramphenicol
23
Q
What dose of famciclovir do you use to treat herpes associated with conjunctivitis and keratitis?
A
90mg/kg BID
24
Q
what is dacryocystitis?
A
infection of the lacrimal system
25
what size catheter is used to flush the lacrimal system
22-24G nasolacrimal canula OR IV catheter w/ stylet removed
26
How many days should it take for an uncomplicated ulcer to heal?
4-7 days
27
Diagnosis of a superficial ulcer
fluorescein positive (no to minimal oedema)
28
List 4 arms of tx. of a superficial ulcer
1. Remove inciting cause
2. Protect w/ lubrication
3. Protect from infection (Chloramphenicol, fusidic acid, triacin TID)
4. Pain relief (systemic NSAIDs)
29
when does a superficial ulcer become an indolent ulcer?
if a superficial erosion has not healed in 7days
30
What is the difference between a primary and secondary indolent ulcer?
1. Primary - result of a defect in the basement mb and epithelial cell adhesion/poor hemidesmosome formation
2. Secondary - due to a underlying dz; eyelid deformity, ectopic cilia, KCS
31
How long does an indolent ulcer take to heal?
weeks - months
32
How frequently should you debride an ulcer w/ a Q-tip?
not more than q10d.
33
Diamond burr keratectomy can not be used for cats or dogs?
cats
34
Contraindications of a grid/punctate keratotomy
- infected/oedematous
| - not in cats dt sequestrum formation risk
35
which ABs have toxicity to epithelialisation?
aminoglycosides
36
Common findings on CE assoc. w/ stromal ulcers
- oedema
- corneal vascularisation
- miosis
- hypopyon
- uveitis
37
How do you treat a stromal ulcer?
Surgical - conjunctival graft
| Medical - sloughing of necrotic tissue and healing via vascularisation w/ aggressive ABs
38
Actions taken to medically treat a stromal ulcer
1. Topical ABs (potent) - Ocuflox (Fluroquinalone) or gentamicin q1-2hs + triacin/fusidic acid if B-haemolytic Streps
2. Systemic ABs - doxycycline
3. Topical atropine 1 drop BID til pupil well dilated
4. NSAIDs (systemic)
39
What bacteria are associated with a melting ulcer?
Pseudomonas, occ. B-haemolytic streps.
40
Use of topical corticosteroids on a stromal ulcer can lead to...
melting ulcer
41
List components of medical tx of melting ulcers
1. ABs q2h Ocuflox + TID fusidic acid or chloramphenicol/Gentamicin
2. Anticollagenase - serum in EDTA/ acetylcysteine
3. Atropine BID (if reflex uveitis)
4. Systemic ABs - doxycycline
5. Systemic NSAIDs at MAX dose
42
CE of a descemetocoel shows what?
1. cornea: oedema, vascularisation, non-staining defect
2. secondary uveitis
3. hypopyon
43
What reflexes test CN 5 and 7?
- palpebral and corneal
44
What CNs are tested w/ PLRs?
CN 2 and 3
45
What CN are tested by the menace response?
2 and 7
46
What CN are tested by the dazzle response?
CN 2
47
What is the normal schirmer tear test value?
>15mm
48
what process typically causes miosis?
uveitis
49
what process typically causes mydriasis?
glaucoma
50
Tx of immune-mediated KCS?
1. cyclosporin eye drops
2. Tacrolimus if cyclosporin ineffective
3. 2nd infections - chloramphenicol
4. Tear replacement - viscotears
5. Steroid drops if pigment/vascular keratitis present
51
what endocrine diseases are associated with KCS?
HypoT, HyperA, DM
52
What drug is used to tx neurogenic KCS?
pilocarpine 1drop/2kg BID in food
53
what is pannus?
Immune-mediated keratitis-lymphocytic/plasmacytic infiltration
54
Pannus tx
cyclosporin 2% BID + predforte 6x daily
55
tx of feline corneal sequestrums
1. Medical lubrication
2. Topical ABs and NSAIDs
3. Can spontaneously slough OR surgical keratectomy +/- graft
56
Technique to remove a corneal FB
25g needle to impale from a perpendicular angle OR moistened Q-tip to elevate edge and wipe off
57
what are the 3 forms of corneal lipidosis?
1. corneal dystrophy
2. corneal lipid degeneration
3. Arcus lipoides cornea
58
CS of uveitis in the dog
1. Red eye (or blue eye)
2. Miosis/dyscoria
3. Low iOP compared to other eye
4. Aqueous flare
5. Keratic precipitates
6. Iritis
7. Chronic uveitis causes increased pigment of iris close to pupil
59
what is the most common cause of uveitis in dogs?
immune mediated
60
what syndrome is associated with snowdogs?
uveodermatological syndrome w/ vitilago
61
what are some infectious causes of uveitis in dogs?
toxoplasma, cryptococcus, Ehrlichia
62
what systemic antibacterial could you use to treat Ehrlichia related uveitis?
doxycycline
63
CS of uveitis in the cat?
- normal iOP (18 +/-6)
- colour change secondary to vasculitis in the iris
- loss of round pupil
64
infectious causes of uveitis in the cat
```
toxoplasma
cryptococcus
FIP
FeLV
FIV
```
65
what neoplasia is associated with uveitis in dogs and cats?
lymphoma
66
uveitis tx
1. Topical corticosteroid (maxidex/predforte)
2. Atropine ointment/drops
3. NSAIDs
67
how can uveitis lead to lipid aqueous?
lipid from blood entering through abnormal uveal-aqueous-blood barrier
68
what endocrinopathies are linked to lipid aqueous?
HyperT, hyperA, DM
69
what ocular change can be associated with pancreatitis?
lipid aqueous
70
list 3 common uveal masses
1. Melanoma
2. Ciliary body tumours
3. Lymphoma
71
what does an iris cyst look like?
brown, translucent, benign - can become free floating in anterior chamber
72
DDx for hyphaema
```
trauma (dogs)
systemic hypertension (cats)
coagulopathy
uveitis
intraocular neoplasia
chronic glaucoma
retinal detachment
```
73
iris atrophy results in..
inability to constrict pupils --> squintingin bright light, no PLR response in visual dog
74
what dog breeds are predisposed to primary glaucoma?
Basset, Cocker Spaniel, Samoyed, Aus. Cattle Dog
75
what is the most common cause of primary glaucoma?
primary angle closure
76
list 5 secondary causes of glaucoma
1. Lens luxation (dogs)
2. Lens swelling - cataracts (diabetic), phaeoclastic uveitis
3. Uveitis (feline)
4. Hyphaema
5. Neoplasia
77
what is a descemet streak?
stretch marks on globe as it enlarges w/ chronic glaucoma
78
tx of primary glaucoma
1. PG agonists - Latanoprost, travoprost, Bimatoprost (causes marked miosis)
79
when is latanoprost contraindicated?
uveitis, lens luxation, CATS
80
tx of secondary glaucoma
1. CAIs - dorzolamine 2%, Brinzolamide 1%
2. +/- Beta-blockers - Timolol
3. Systemic NSAIDs
4. Pred acetate topically (if no ulcers)
5. Tx underlying disease
81
list two surgical approaches to decrease aqueous production
1. Cyclocryosurgery - ciliary body is frozen through the sclera
2. Cyclophotocoagulation - a laser used to destroy ciliary body
82
when is enucleation indicated?
1. painful, non-visual eye
83
what is a aphakic crescent associated with?
lens luxation/subluxation
84
sequelae of lens luxation
1. secondary glaucoma
2. secondary retinal detachment
3. luxated lens will develop cataracts
85
what is nuclear sclerosis?
a normal ageing process - thickening and hardening of lens proteins with age (>7yo)
86
what dog breeds are associated with hereditary cataracts?
Golden retrivers, min. schnauzers, cocker spaniels
87
what are some common cause of cataracts in cats?
secondary to trauma, uveitis, diabetes (less common than dogs), retinal disease
88
Define an incipient cataract
small opacity and vision is maintained <15% lens
89
Define an immature cataract
vision impaired and fundus is seen indistinctly. A tapetal reflex is still seen,
15-99% of lens
90
Define a mature cataract
entire lens is opaque w/ no tapetal reflex or fundus visible
91
Define a hypermature cataract
the cortex may liquefy and permit visualisation of the fundus around the opacity
'sparkles' in the anterior lens
92
what is vitreous hyalosis?
calcium/lipid floating in the vitreous
93
what is synchysis scintillans?
cholesterol in the vitreous -- snow globe effect
94
what is the difference between a feline and canine optic disc?
feline is in the tapetal fundus - small round w/ no myelin
| canine - margin of tapetal and non-tapetal fundus and has myelin +/- pigment around it making it look fluffier
95
what diseases are associated with hypertensive retinopathies?
- CKD, thyroid disease, DM, hyperA, Conns Dz, primary hypertension, hyperviscosity
96
what dose of amlodipine for a cat w/ hypertension? Sys BP >170mmHg
Amlodipine 0.1-0.2mg/kg PO SID
97
CS of progressive retinal atrophy
- pupil may have a larger resting size than normal
- PLRs may persist until v. late in dz
- retinal vascular attenuation
- hyper-reflective tapetum
98
what drug can induce irreversible feline toxic retinopathy?
enrofloxacin
99
what can cause young abbyssinian cats to go blind?
feline progressive retinal atrophy
100
on a fundic exam of a cat you notice a bright spot lateral to the optic disk - top DDx?
taurine deficiency
101
what is your typical signalment for sudden acquired retinal degeneration?
small, white fluffies, middle aged, female dogs
102
list some infectious causes of chorioretinitis in the dog
1. Bacterial - Erhlichia canis, Anaplasma platys
2 Fungal - cryptococcus, aspergillus
3. Protozoal - toxoplasma, neospora, leishmania
4. Parasitic - toxocara
103
list 3 immune-mediated causes of chorioretinitis in dogs
- uveodermatologic syndrome
- vasculitis
- thrombocytopaenia
104
List infectious causes of chorioretinitis in the cat
1. Viral: FIP, FIV, FeLV
2. Fungal: cryptococcus
3. Protozoal: toxoplasma
4. Parasitic: toxocara
105
what are the clinical signs associated with acute chorioretinitis?
o Fluid,cells, protein exudate increase from choroid = hypo-reflective w/ vasculitis (haemorrhage/retinal detachment)
o Often focal
o Often active uveitis as well
106
what is "Collie Eye anomaly"?
congenital disease which can affect the optic nerve, retina, choroid, sclera.
Can cause mild disease through to severe disease leading to retinal detachment
107
why do you need to assess for Collie Eye in puppies <8wks old?
a pale spot in the choroid lateral to the optic disc is only visible before pigment if formed over the non-tapetal fundus
108
list 3 causes of optic nerve disease
- optic nerve atrophy (secondary to glaucoma, PRA)
- optic neuritis
- papilloedema
109
list 4 anatomical structures that can cause central blindness if damaged
1. Pre-chiasmal
2. Chiasma
3. optic Tract
4. central
110
CS assoc. w/ horners
miosis, enopthalmus, protis, 3rd eyelid protrusion, periorbital BV dilation
111
what drug do you use to pharmacologically test which order neuron is effected in horner's?
phenylephrine 1%
112
Dazzle tests
o CN 2 (optic)
| o CN 6 (abducens)
113
Palpebral tests
```
o CN5 (trigem)
o CN 7 (facial)
```
114
PLR tests
o CN 2 (optic)
o CN 3 (oculomotor)
o Parasympathetic
115
Menace tests
o CN 2 (optic)
o CN 7 (facial)
o CN 6 (Abducens)
o *note: learned response, not present until > 12w
116
Vestibulo-ocular tests
CN 8 (eye tracking…)
117
Obstacle course tests
CN 2 (optic)
118
what can cause retrobulbar abscesses?
FB migration (grass seeds), stick injuries, tooth root infections (upper molars)
119
tx of a retrobulbar abscess
* Lance and drain via small stab incision behind last upper PM (4) and using blunt closed forceps (no sharp instruments!). Create a draining tract from the retro-bulbar space.
* Appropriate antibiotics ideally based on C&S.
* FB materials can sometimes autolyse (grass seeds) vs. FB sx referral
120
Ddx for a retrobulbar abscess
- neoplasia, cysts, myositis, mucocoele, retro-bulbar haemorrhage
121
what causes dogs to look like they have a headache?
eosinophilic/extraocular muscle myositis
122
tx of extraocular muscle myositis
immunosuppressive pred systemic
| + gabapentin (pain)
123
Prognosis for vision in proptosis in cat vs dog
poor in cats
| guarded in dogs (better in brachys)
124
tx for proptosis
- lubricate
- lateral canthotomy to give room to replace eye
- suture lids together w/ mattress sutures (using meiobium gland openings) tarsorraphy.
