Ophthalmology Flashcards
(238 cards)
1
Q
what are the main signs of eye pain?
A
blepharospasm
reduced palpebral fissure
ocular discharge/epiphora
hyperaemia
2
Q
what is blepharospasm?
A
increased blink rate
3
Q
what is epiphora?
A
watery eyes
4
Q
what is hyperaemia?
A
redness
5
Q
what are the local signs of occular pain?
A
photophobia
miosis
third eyelid protrusion
head shy
self trauma
6
Q
what is miosis?
A
constricted pupil
7
Q
what are the systemic signs of occular pain?
A
reduced appetite
quiet
subdued
depressed
lethargic
headache
8
Q
how should occular cases be triaged?
A
systemic signs
brief outline of occular signs
speed of onset
duration
9
Q
when should patients with occular pain/issues be seen in practice?
A
same day wherever possible
10
Q
what is the downside of using standard pain scoring to assess occular pain?
A
it is influenced by blepharospasm
11
Q
what are the 3 sections of the ophthalmic patient pain score?
A
overall demenour
observation of blepharospasm
rubbing of the eye
12
Q
what score on the ophthalmic patient pain score suggests analgesia is required?
A
> 3
13
Q
what are the main methods of management of ophthalmic pain?
A
medical - topical and systemic
surgical
14
Q
who must advocate for the patient?
A
veterinary team
15
Q
what must be treated?
A
cause of the pain
16
Q
what may be causing an animal occular pain?
A
scratchy dry lids
acute ulcer
uveitis
chronic glaucoma
orbital swelling
unknown - unable to open eye to see
17
Q
how may dry eyelids be treated?
A
lubrication with HA drops
18
Q
how may pain from acute ulcers be treated?
A
bandage contact lens
19
Q
how do bandage contact lenses prevent pain?
A
covers nerve endings
20
Q
how may pain from uveitis be treated?
A
atropine or Cyclopentolate drops to relax muscle
21
Q
how may pain from chronic glaucoma be treated?
A
enucleation
22
Q
how may pain from orbital swelling be treated?
A
NSAIDs
opioids
23
Q
how may an eye that cannot be opened be treated?
A
LA
sedation
GA
24
Q
how should blind or partially sighted patients be handled?
A
go slowly
hand on chest initially
talk to them
guide then whilst walking
avoid bumping into things
25
why is avoiding bumping into things essential if the eye is fragile?
could lead to rupture
26
how should patients be handled for occular exam?
assessment of temperament - is muzzle needed
keep steady
keep calm
placed at the table edge
reward and reassure
27
what are some of the main causes of vision loss?
cataract
glaucoma
SARDS
toxins
PRA
brain disease or trauma
28
what are the 2 main reasons that cateracts develop?
inherited
diabetic
29
how is glaucoma caused?
inherited genetic defect
secondary to intraocular neoplasia, uveitis or lens luxation
30
how is glaucoma treated?
medically managed initially
surgical shunt implant
laser TSCP/ECP
ultimately enucleation
31
what is SARDS?
sudden acquired retinal degeneration syndrome
32
how is SARDS confirmed?
flat line on electroretinogram
33
how is SARDS treated?
no treatment
34
what toxins can cause blindness?
ivermectin poisoning
enrofloxacin in cats
35
what is PRA?
progressive retinal atrophy
36
what breeds is PRA common in?
cocker spaniels
37
what type of vision is lost first with PRA?
night and then day
38
how can PRA be diagnosed?
simple maze test with lights on and off
ERG can show if rods not responding and so night vision lost
39
how important is sight to animals?
scent and hearing most important
adjust very well to blindness
40
how can owners support their blind pets at home?
online forums for blind pet owners
RSPCA
buster collars
guide leads
doggles
voice commands for stairs etc
behaviour training
lead walks offer more support
41
will eye ulcers heal if we do nothing?
if simple will heal in 7 days with no intervention
42
what must be done if ulcers are lasting more than 7 days?
investigation of underlying issue
43
what is the issue with not treating ulcers?
pain
infection risk
delayed healing
risk of keratomalacia
44
how does keretomalacia occur?
enzymes in tears break down cornea which can lead to globe perforation
45
what may happen if ulcers are not correctly managed?
perforation
endophthalmitis
glaucoma
phthisis
blindness
46
what typeof epithelium is the cornea formed from?
transparent stratified squamous epithelium
47
what is an integral part of the cornea?
tear film on upper surface
48
what is the limbus of the eye?
transition zone to sclera
49
what is the sclera?
fibrous tunic
50
what is the role of the sclera?
gives globe rigidity
51
what are the different ulcer depths?
superficial
deep
descemetocoele
perforation
52
how can ulcers be classified?
depth of stroma affected
size
type
53
what is the effect on the stroma of a descemetocoele ulcer?
all stroma is lost
54
when is an eye classed as fragile?
>50% stromal loss
55
what layer of the eye can ulcers reach that makes the eye extremely fragile?
Descemet's layer
56
what can cause eye rupture if eye is fragile?
any increase in IOP
57
what may cause increased IOP?
barking
jugular samples
coughing
vomiting
collar
firm restraint
58
what breeds are commonly affected by severe ulcers?
brachycephalic breeds
59
how should animals with fragile eyes be treated?
avoid pressure on neck/lids
keep venous pressure low to keep IOP low
avoid stress
caution with occular tests used
ensure meds given regularly
keep eye area clean
60
what ulcer types are there?
SCCED
stromal ulcers
melting ulcers
descemetocoeles
perforation
61
what is SCCED?
spontaneous chronic corneal epithelial defect
62
how can SCCED be treated?
algar brush
grid
superficial keratectomy
63
what is a superficial keratectomy?
top layer of the cornea removed
64
how are stromal ulcers / feline sequestrum treated?
medical
surgical graft
65
how are melting ulcers treated?
intense medical management initially
corneal cross linking if cornea unstable
corneal graft
66
how are descemetoceles treated?
structural support imperative
corneal-conjunctival transposition
67
how is eye perforation treated?
suture closed
graft
corneal transplant
68
how should patients with fragile eyes be managed around anesthesia?
low stress
smooth pre-med (IV) and induction
smooth recovery
consider not reversing premed
69
where should horses be kept following eye surgery?
dark stables to allow atropine to be used
70
what is involved in post occular surgery care?
harness only
no jugular samples
buster collar needed
monitor and treat pain
administer meds
keep wounds clean and dry
keep patient calm
71
what types of trauma are ocular emergancies?
sharp trauma
blunt trauma
proptosis
penetrating FB
72
what is proptosis?
eyelids trapped behind the globe which pushes the eye out of the orbit
73
what are the priorities for occular emergencies?
CVS stability
analgesia
occular surface support
eye lubrication
prevent further trauma
stabilise any FB
buster collar to prevent self-trauma
74
when do puppies develop a menace response?
between 8-12 weeks
75
what can be caused by cat claw injury to the eye?
corneal laceration
lens puncture
capsular tear
cataract formation
lens induced uveitis
76
what may be needed to treat cat claw injuries?
cataract surgeries with phaecoemulsification
corneal laceration repair
medical treatment of uveitis
77
how can risk of cat claw injury be reduced?
ensure owners with cats and puppies are aware of when mencae response develops
78
what visually about the eye can indicate glaucoma?
blue cornea
red sclera
conjunctiva
79
what can be caused by glaucoma?
blindness and pain
80
what can chronic glaucoma cause?
buphthalmic eye
81
what is a buphthalmic eye?
eyeball is bigger as globe is stretched
82
does the eyeball move from its position in the orbit if glaucoma is seen?
no - remains in it's normal position inside the orbit
83
what is normal IOP?
10-25 mmHg
84
what IOP can be seen with glaucoma?
>30 mmHg
85
what can a IOP of >40mmHg cause?
blindness in 24-28 hours
86
what can cause exophthalmos?
FB causing retrotubular abscess or cellulitis
elevator slip trauma if recent dental work
stick injuries
87
what are the signs of retrotubular masses?
pain on opening mouth
exophthalmus
excessive conjunctiva visible - especially third eyelid
88
what is exophthalmus?
eye is pushed forwards
89
what is the role of lubricant eye drops?
protect
soothe
support healing
provide nutrients to eye
90
what is the role of antibiotic eye drops?
treatment
prophylaxis
91
what types of anti-inflammatory eye drops are available?
NSAIDs
steroids
92
what is the role of immune modulator eye drops?
treatment of immune mediated disease
93
what is the role of anti-glaucoma eye drops?
lower IOP
94
what is the role of mydriatic eye drops?
dilation of the pupil
95
what mydriatic is commonly used?
atropine
96
what is the role of LA eye drops?
diagnostic procedure
pre-op
97
what LA is commonly used for eyes?
proxymetacaine
98
what can serum eye drops be made from?
FFP
serum (patients own or donor)
99
how can serum eye drops be made?
defrost frozen plasma
place needle free spike into plasma bag
draw up 3 mls plasma and transfer into bottles
store bottles or syringes of plasma in the freezer
defrost on day of use
100
how long can serum eye drops be kept in the fridge for?
max 3 days
101
when should serum drops be applied?
every 1-2 hours
102
what is essential when making serum eye drops?
process should be as sterile as possible
103
what can serum eye drops be used for?
melting ulcers
prevention of keratomalacia
104
what must be checked before administering eye drops?
correct meds for the correct eye
105
how much eye drops are needed?
one drop sufficient
106
how much time should be left between each drop?
10 mins
107
how much time should be left between gel drops and ointment?
60 mins
108
what must not touch the surface of the eye?
nozzle
finger
109
what determines order of drop administration?
viscosity
110
in what order should drops be applied?
watery/aqueous drops
suspensions
gel
ointment
111
what is the role of lubricants?
support healing in all ocular surface disease
nutrition of cornea
reduce evaporation
prevent perioperative ulceration
KCS management
comfort
112
when will lubricants not be used in ocular surface disease?
if the eye has ruptured
113
look at eye drops table
plz :)
114
what are the main patient factors to consider when preparing for ophthalmic surgery?
mobility
systemic health
is pre-op testing needed
BOAS?
will eye drops be needed prior to surgery
when and where should catheter be placed
many are diabetic - insulin needs
115
how can induction for ophthalmic patients be made smoother?
waiting with owner
ensure adequate depth before intubation
116
how should patients be positioned for ophthalmic surgery?
vacuum bags to prevent movement
op vet usually to position
117
where should monitoring equipment be placed during ophthalmic surgery?
towards the back wherever possible
118
what type of ET tube may be used during ophthalmic surgery?
armoured ET tube
119
what additional anaesthesia may be used in ophthalmic surgery?
NMBA
120
what is required if NMBAs are used?
ventilation
121
what is the benefit of NMBA for ophthalmic surgery?
central and still eye
122
how should eyelids be prepared for surgery?
wear gloves
apply large volume of lubricating gel to the eyes
small sharp clippers used
clip area as close as possible without causing trauma or irritation
flush hairs and lubricant away with saline
123
is clipping required for globe surgery?
no
124
what should be placed in the eye before clipping for eyelid surgery?
lubricating gel to catch hairs
125
what must always be used to surgically prep the eye?
povidine iodine solution
126
what must never be used for eye prep?
hibi
iodine scrub or tincture
127
what ratio of povidine iodine to sterile saline should be used for the globe?
1:50 iodine:saline
128
what ratio of povidine iodine to sterile saline should be used for the eyelids?
1:10 iodine:saline
129
what length of contact time is required for povidine iodine solution?
2 minutes
130
what should be done once the povidine iodine has had its 2 minute contact time?
flush out with saline
131
what should be used to remove gel and hair from the eye following clipping?
gauze swabs and sterile saline
132
can povidine iodine solution be made up in advance?
yes can keep for up to a week
133
what amount of povidine iodine to saline will make a 1:50 solution?
2ml in 98ml saline
134
what order should the globe and lids be prepped?
globe first (1:50)
then eyelids (1:10)
135
why must the globe be flushed with sterile saline after the 2 minutes povidine iodine contact time?
prevents corneal toxicity
136
what surgical equipment may be needed for ophthalmic surgery?
patient drapes
surgeons chair with arm rests
gown and gloves
equipment and chair drapes
pre-drawn saline flush
137
what equipment may be used for ophthalmic surgery at referral level?
operating microscope with sterile cover
ventilator
muscle stim if NMBA used
phaecoemulsification machine if cateract surgery
138
what is essential when cleaning and packing ophthalmic kit?
extreme care taken
very fragile and expensive
no towels!
139
what are the main types of eye surgical kits?
lid
corneal
phaeco
140
what suture material is often used for lids?
5-0 or 6-0 vicryl
141
what suture material is often used for cornea?
8-0 or 9-0 vicryl
142
what type of needle is used for corneal suture?
spatulated
143
what drapes may be used for ophthalmic surgery?
fenestrated
sticky
may have pouch to catch fluid
144
what block may be used for enucleation?
retrotubular
145
what are the 2 main methods of enucleation?
trans-conjunctival
transpalpebral
146
how does transconjunctival enucleation work?
2 phase
incision around limbus and eye removed
then lids and conjunctiva follow
147
what may be used instead of NMBAs during occular surgery to stabilise the eye?
stay sutures
148
what happens during transpalpebral enucleation?
en block removal
eyelids sutured closed first
lids and eyeball removed all in one
149
when would trans-palpebral enucleation be used?
tumour or infection
150
what are some specific anaesthetic considerations relating to enucleation?
stimulation of oculo-cardiac reflex
excessive traction on chiasm
haemorrhage
151
what is the oculo-cardiac reflex caused by?
pressure on the eye stimulating the vagus nerve
152
what happens during the oculo-cardiac reflex?
reflex bradycardia due to vagal stimulation
153
what is the effect of traction on the optic chiasm?
optic nerves are linked
avulsion from excessive traction can lead to blindness in other eye
154
what animals are more at risk from blindness following traction on chiasm?
cats
155
what are the options for haemorrhage during enucleation?
collagen pads
powders
adrenaline
pressure
156
where may owners see mild post op haemorrhage following enucleation?
nostrils
157
what are some general surgeries seen in the eye area?
entropian
mass removal
rhytidecomy
distichasis
medial canthoplasty
cherry eye
lid to lid transposition
parotid duct transposition
158
what techniques may be used for entropion correction?
holtz-celcus - crescent shaped incision on eyelid
159
what technique may be used for eyelid mass removal?
wedge excision
160
what is rhytidectomy?
removal of excess skin that may be impacting eyes/vision
(droopy dog facelift)
161
what is distichasis?
extra lashes that rub against eye due to their position on the eyelid
162
how can distichasis be treated?
cryosurgery
electrolysis
163
what is a medial canthoplasty?
reshaping of medial canthus to prevent rubbing on the cornea
164
what dogs is medial canthoplasty often performed in?
pugs
165
what are lid to lid transpositions used for?
replace defects
166
what can parotid duct transposition be used for?
dry eye
167
what position must the eye be in for corneal surgery?
horizontal and still
ideally central
168
how can eye position be stabilised for corneal surgery?
NMBA and ventilation
stay sutures
169
what is involved in corneal surgery?
removal of damaged cornea
free or advancement graft to cover deficit
170
what is a common cause of blindness?
cateracts
171
what are the main causes of cataracts?
inherited
acquired through diabetes mellitus
172
how should patients be assessed before cataract surgery?
gonioscopy
ERG
US for tumour
check if giving post op meds is practical for O
are their financial constraints
173
what is the purpose of gonioscopy?
assess eye drainage angle
174
what condition is indicated by gonioscopy?
inherited glaucoma
175
how is gonioscopy performed?
patient conscious
LA drops used
placed on eye
176
what is the purpose of ocular ultrasound?
assess structures of the eyes
177
what may be diagnosed through ocular ultrasound?
lens structure
cataracts
retinal detachment
retrotubular mass
FB
178
can ocular ultrasound be performed conscious?
yes
179
how is the patient prepped for ocular US?
proxymetacaine to desensitise cornea
lots of gel used
180
what is ERG used for?
assessment to see if retina is functional
181
what is recorded by ERG?
retinal electrical response to light stimulus
182
does the patient need to be anaesthetised for ERG?
can be conscious or sedated
183
how many diabetic patients develop cataracts within 6 months of diagnosis?
50%
184
how many diabetic patients develop cataracts within 12 months of diagnosis?
75-80%
185
what are the risks associated with untreated diabetic cataracts?
lens capsule rupture
lens induced uveitis
186
do diabetics need to be well controlled for surgery?
no
187
what is the overall aim of cataract surgery?
restores vision
188
what type of surgery is cataract surgery?
intra-ocular
189
what is the success rate of cataract surgery?
85%+
190
what is essential pre cataract surgery?
pre-op work up to check eye health
191
what is involved in pre-cataract surgery work-up?
ERG
US of drainage angle
gonioscopy
full bloods and urinalysis
192
what is the purpose of pre-cataract ultrasound?
drainage angle of eye
assess for detached retina / masses
193
what is the average cost of cataract surgery?
£4-5k depending on one or both eyes
194
how often may meds be needed post cataract op?
up to 12 times daily in the first week
195
how long should patients be kept quiet for following cataract surgery?
2 weeks
196
what eye drops are needed post cataract surgery?
steroids
NSAIDs
glaucoma meds
antibiotics
lubricants
197
what is the role of steroid and NSAID eyedrops following cataract surgery?
topical control of uveitis
198
what is the role of glaucoma eyedrops following cataract surgery?
minimisation of IOP spike
199
how long will antibiotic drops be given post glaucoma surgery?
until wounds heal
200
what are the main risk factors of ophthalmic surgery anaesthesia?
patients tend to be older
co-morbidities likely
BOAS common
cardiac issues
201
what analgesia is likely used for ophthalmic surgery?
local - skin line or retrotubular
systemic NSAID/opioids
202
what is a commonly used drug for NMBA?
atracurium
203
how long does atracurium last for?
15-35 mins
204
what can be caused by atracurium when given IV?
histamine release - give slowly
205
what conditions of the patient must be avoided to prevent prolonging NMB?
hypothermia
acidosis
hypokalaemia
206
why is NMBA safe in renal and hepatic patients?
non-cumulative
207
what is seen with brachycephalic ocular syndrome?
lower medial entropian
shallow orbit
macropalpebral fissure
lagophthalmos
medial caruncular trichiasis
pigmentary ketatitis
epiphora
208
what does a shallow orbit in brachycephalic dogs lead to?
relative exophthalmus
209
what is lagophthalmos?
sleeping with lids incompletely closed
210
what is medial caruncular trichiasis?
hairs rubbing on the eye
211
what is pigmentary ketatitis?
pigment forming on cornea
212
what can cause epiphora in brachycephalic dogs?
kinking of nasolacrimal canaliculi and obscuring punctum
213
what can brachycephalic ocular syndrome be exacerbated by?
concurrent issues such as KCS or distichiasis
214
how can the compromised airway of brachycephalic breeds be managed?
preoxygenate
O2 in recovery
manage hyperthermia
reduce stress
home ASAP
URT obstruction a risk
delayed extubation
215
what can reduce regurgitation risk?
shorter starve time
216
what drugs may increase regurgitation risk?
opioids due to reduction in GI motility and so delayed gastric emptying
217
what can be done to stimulate peristalsis in BOAS dogs?
paracetamol if liver ok
visceral analgesia
lidocaine
get walking and moving
ensure hydrated
low fat food to speed gastric emptying
218
how should diabetic patients be managed before surgery?
starve in the morning and withhold glucose
219
what are diabetic patients at increased risk of during eye surgery?
systemic hypertension
dry eye
delayed healing
infection risk increased
220
why do diabetics have increased fluid requirements?
glucoseuria
221
what is involved in client communication around eye surgery?
manage expectations
train to give eye drops
train dog to receive drops
clarity around high bills
monitoring tests for at risk breeds
habituation of puppies to eyedrops
222
how much more likely than the normal dog are brachycephalic breeds to get KCS?
3.6 x
223
how much more likely than the normal dog are brachycephalic breeds to get corneal ulcers?
20 x
224
what are the main benefits of ocular nurse clinics?
monitor normal patients for subclinical disease
O education
support medication compliance
positive reinforcement training for receiving eyedrops
STT in high risk breeds
225
what are the layers of the tear film?
lipid
aqueous
mucus
226
what is the function of the lipid layer of the tear film?
prevents evaporation
aids distribution
227
what is the function of the aqueous layer of the tear film?
supplies corneal nutrition
antibacterial properties
removal and remodelling through proteases and antiproteases
228
what is the role of the mucus layer of the tear film?
lubrication
reflective properties
anchors aqueous layer to cornea
229
what is required for a functional lacrimal unit?
normality
230
what are the majority of cases of KCS caused by?
immune mediated adenitis
231
what is KCS?
deficiency of aqueous tear
232
what dogs are predisposed to KCS?
WHWT
yorkie
bulldogs
pugs
ESS
CKCS
233
what is used to diagnose KCS?
schirmer tear test and concurrent clinical signs
234
what mm/min STT reading is normal?
15-25
235
what is indicated by 10-14 mm/min STT reading?
early / suspicion of KCS
236
what is indicated by 6-10 mm/min STT reading?
moderate KCS
237
what is indicated by 0-5 mmmin STT reading?
severe KCS
238
what are the common clinical signs of KCS?
strings of adherent mucus
poor corneal clarity
poor corneal shine
poor Purkinjie reflex
low STT reading
