OPHTHALMOLOGY Flashcards
1
Q
what are the bones of the bony orbit
A
frontal maxilla zygomatic sphenoid lacrimal ethmoid
2
Q
what is the base of the bony orbit called
A
the orbital rim
3
Q
which bone makes up the majority of the roof of the bony orbit
A
frontal bone
4
Q
what bone makes up the majority of the floor of the bony orbit
A
maxilla
5
Q
what is the purpose of the orbital rim
A
protect the eye from direct trauma
6
Q
what are the thinnest parts of the bony orbit
A
medial wall and orbital floor
7
Q
what is a blowout fracture and its complications
A
medial wall/orbital floor fractured due to impact on the orbital rim
orbital contents can become trapped, damage to infraorbital NVB leading to general sensory deficit of facial skin
8
Q
complication of fractured zygoma
A
diplopia
suspensory ligament of the eye attaches to the zygoma and droops in zygomatic fracture, causing one eye to lower
9
Q
common cause of diplopia in young men
A
zygomatic fracture
10
Q
the two parts of the orbicularis oculi
A
orbital part
palpebral part
11
Q
what is the orbital septum and what is its function
A
a sheet of fascia deep to the ocularis oculi
prevents spread of infection from superficial to deep
12
Q
where are the tarsal glands located and what is their purpose
A
embedded in tarsi
lipid secretion
13
Q
what is the function of the conjunctiva
A
a defensive barrier to foreign bodies penetrating deep to it into the orbit
14
Q
what I the conjunctival fornix
A
where the conjunctiva covering the eye meets the conjunctiva covering the lower eyelid
15
Q
what is the limbus
A
corneoscleral junction
16
Q
what is the function of the lacrimal gland
A
produces lacrimal fluid (tears)
17
Q
innervation of the lacrimal gland
A
parasympathetic (CNVII)
18
Q
where does lacrimal fluid drain out of the eye
A
lacrimal puncta to the nasolacrimal duct
19
Q
what makes up the outer (fibrous) layer of the eye
A
sclera and cornea
20
Q
what makes up the urea (vascular) layer of the eye
A
iris, ciliary body and choroid
21
Q
what is the inner layer of the eye called
A
the retina
22
Q
what is the anterior chamber of the eye
A
part of the anterior segment
between the cornea and iris
contains aqueous humour
23
Q
what is the posterior chamber of the eye
A
part of the anterior segment
between the iris and suspensory ligaments
contains aqueous humour
24
Q
what is the posterior segment of the eye
A
behind the eye
contain vitreous humour
25
where is aqueous humour produced in the eye
ciliary processes in the ciliary body
26
what is the purpose of aqueous humour
nourishes the anterior lens and cornea
27
where is aqueous humour reabsorbed
the scleral venous sinus (canal of scheme) at the iridocorneal angle
28
the ophthalmic artery is a branch of which main artery
internal carotid
29
what type of artery is the central artery of the retina
end artery
30
what are the main branches of the ophthalmic artery
nasal cavity branches
| forehead (scalp) branches
31
what veins drain the orbit
```
posteriorly
superior/inferior ophthalmic vein
forehead (scalp) vein
anteriorly
facial vein
```
32
what is the danger triangle of the face
an area of the face which is drained by the facial nerve
this superficial venous system connects with the deep system draining the eye and is a possible route for infection to enter the brain
33
what are the four main parts of the retina
fundus
optic disc
macula
fovea
34
from anterior to posterior, what are the layers of the retina
axons of the ganglions cells
ganglion cells
photoreceptors
35
which axons cross at the optic chiasm
nasal axons
36
what are the extra ocular muscles
lateral, medial, superior and inferior rectus
inferior and superior oblique
levator palpeerde superioris
37
origin of the EO muscles
common tendinous ring
38
innervation of the EO muscles
LR6 SO4 AO3
39
which muscles work together to achieve pure elevation
superior rectus and inferior oblique
40
which muscles work together to achieve pure depression
superior oblique and inferior rectus
41
CNV1 supplies sensory innervation to
upper eyelid
cornea
conjunctiva
skin of the root/bridge/tip of nose
42
CNV2 supplies sensory innervation to
skin of the lower eyelid, over the maxilla, ala of nose, skin/mucosa of the upper lip
43
CNV3 supplies sensory innervation to
skin over temporomandibular joint apart from the angle of the mandible (C2,3)
44
which nerve passes through the supraorbital foramen
CNV1
45
which nerve passes through the infraorbital foramen
CNV2
46
sensory afferent limb of the blink (corneal) reflex
CNV1
47
motor (efferent) limb of blink (corneal) reflex
CNVII
48
where does CNIII connect to the CNS
between midline and pons
49
route of CNIII
leaves brain at junction between midline and pons
passes through superior orbital fissure
somatic motor to eye muscles
presynaptic parasympathetic axons to the ciliary ganglion
superior and inferior divisions
50
what types of nerves are long ciliary nerves
sympathetic
| somatic sensory
51
what types of nerves are short ciliary nerves
sympathetic
| parasympathetic
52
what type of ciliary nerve forms the first part of the blink reflex
long ciliary nerves
| somatic sensory
53
eyes open wider
| sympathetic/parasympathetic
sympathetic
54
pupils get wider
| sympathetic/parasympathetic
sympathetic
55
pupils constrict
| sympathetic/parasympathetic
parasympathetic
56
focus on near objects
| sympathetic/parasympathetic
parasympathetic
57
reflex lacrimation
| sympathetic/parasympathetic
parasympathetic
58
what type of muscle fibres does LPS contain
skeletal and smooth muscle
59
how do postsynaptic sympathetic fibres reach LPS
```
superior cervical sympathetic ganglion
internal carotid nerve
internal carotid plexus
axons carried on the ophthalmic artery
branches to LPS
```
60
what muscle is responsible for the sympathetic widening of the eyes
LPS
61
what type of nerves are responsible for dilating the pupil
sympathetics
62
action of mydriatic drugs
dilate the pupil
63
what muscles are responsible for dilating the pupil
dilator pupillae fibres
64
what type of nerve constrict the pupil
parasympathetics
65
what is a mitotic pupil
non-physiologically constricted
66
a mitotic pupil is a component of which syndrome
Horner's syndrome
67
a fixed-dilated pupil as a sign of pathology to which nerve
CNIII
68
what muscle fibres are responsible for pupillary constriction
sphincter pupillae fibres
69
what is the afferent limb of the pupillary light reflex
CNII (ipsilateral)
70
what is the efferent limb of the pupillary light reflex
CNIII (bilateral)
71
pupillary light reflex only occurs in one eye
| true/false
false
| a consensual light reflex occurs in the contralateral eye
72
relaxation of the ciliary muscle is caused by which nerve type
relaxation of the ciliary body is caused by the absence of parasympathetic firing
73
relaxation of the ciliary muscle occurs in which type of vision
far vision
74
in far vision, what shape is the lens
flat
75
contraction of the ciliary muscle is caused by which type of nerve
parasympathetic
76
contraction of the ciliary muscle occurs in what type of vision
near vision
77
what shape is the lens in near vision
spherical
78
the accommodation reflex is in response to what type of vision
near
79
what are the three aspects of the accommodation reflex
pupillary constriction
bilateral convergence
bilateral relaxation of the lens (contraction of ciliary muscles)
80
what nerve is responsible for the accommodation reflex
CNIII
81
what enzyme do tears contain
lysozyme
82
afferent limb of reflex tears
CNVI
83
efferent limb of reflex lacrimation
CNVII (parasympathetic)
84
symptoms of Horner's syndrome
miosis (constricted pupil)
ptosis (drooping eyelid)
reduced sweating
increased warmth and redness
85
what causes Horner's syndrome
impaired sympathetic innervation to the head and neck
| root of neck trauma, carotid dissection, internal jugular vein engorgement, deep cervical node mets, pancoast tumour
86
causative pathogens of bacterial conjunctivitis in neonates
staph aureus
neisseria gonorrhoeae
chlamydia trachomatis
87
causative pathogens of bacterial conjunctivitis in children/adults
staph aureus
strep pneumoniae
h influenzae (esp in children)
88
treatment of bacterial conjunctivitis
topical antibiotic
| chloramphenicol
89
causative pathogens of viral conjunctivitis
adenovirus
herpes simplex
Herpes zoster
90
signs of chlamydial conjunctivitis
chronic history
unresponsive to treatments
bilateral involvement in young adults
may have symptoms of urethritis/vaginitis
91
causes of microbial keratitis
bacteria
viruses
fungi
92
what is a hypopyon
inflammatory cells in the anterior chamber of the eye
93
herpetic keratitis may be associated with
dendrites ulcer
94
why should steroids be avoided in herpetic keratitis
can cause corneal melt and perforation of the cornea
95
why would you give antibiotics in adenovirus keratitis
to prevent secondary infection
96
fungal causes of keratitis include
acanthomoeba
| pseudomonas aeruginosa
97
signs orbital cellulitis
pain - esp on eye movements
often associated with paranasal sinusitis
pyrexia
erythema/oedema
98
what may a CT show in orbital cellulitis
orbital abscess
99
causative pathogens of orbital cellulitis
staph, strep, colifroms, H influenzae, anaerobes
100
signs of endophthalmitis
very painful
decreasing vision
very red eye
101
what is endopthalmitis
inflammation of the interior eye
102
most common cause of endophthalmitis
staph epidermis
103
pathogens associated with chorioretinitis
CMV in AIDS
toxoplasma gondii
toxocara canis (worm)
104
treatment of dendrites ulcers
antivirals (aciclovir)
105
treatment of chlamydial conjunctivitis
topical oxytetracycline
106
where is CSF produced
secretory epithelium of the choroid plexus
107
where is the choroid plexus found
in the ventricles of the brain
108
what is the function of CSF
```
mechanical protection (shock absorption)
homeostatic function
circulation (minor exchange of nutrients and waste products between blood and brain)
```
109
how is CSF analysed
lumbar puncture
110
normal appearance of CSF
colourless
111
which ventricles is choroid plexus found in
lateral, 3rd and 4th
112
what is the name of the foramen the connects the lateral ventricles to the 3rd ventricle
foramen of munroe
113
what is the name of the foramen that connects the 3rd ventricle to the 4th ventricle
aqueduct of sylvius
114
what are the names of the foramina that release CSF into the subarachnoid space
foramina of luschka (laterally)
| foramen of megendie (median)
115
describe the circulation of CSF
lateral ventricles > foramen of Monroe > 3rd ventricle > aqueduct of sylvius > 4th ventricle > foramina of Luschka/foramen of magendie > subarachnoid space > arachnoid granulations > superior sagittal sinus
116
what does the BBB consist of
capillary endothelium
basal membrane
perivascular astrocytes
117
what is the function of the BBB
protect the brain from infection and toxins
118
what is hydrocephalus
accumulation of CSF in the ventricular system or around the brain leading to enlargement of one or more ventricles and increase in CSF pressure
119
cause of papilloedema
raised ICP transmitted to the subarachnoid space surrounding the optic nerve
120
visual symptoms of papilloedema
enlarged blind spot
blurring of vision
visual obscurations
loss of vision
121
what is the function of bicarbonate in the aqueous humour
buffers H+ produced in the cornea and lens by anaerobic glycolysis
122
what are the four main regions of a photoreceptor
outer segment
inner segment
cell body
synaptic terminal
123
type of photoreceptors
rods and cones
124
what is the name of the visual pigment molecule present in rods
rhodopsin
125
what happens to rhodopsin in the presence of light
it is converted to all-trans-retinal
126
what effect does all-trans-retinal have of cGMP
causes it to decrease
127
what is the effect of a decrease in cGMP
hyperpolarisation of the membrane
128
how does spacing of photoreceptors affect visual acuity
decreased spacing (closer together) increases VA
129
what are rods and cones used for
cones - colour
| rods - dim light
130
how are rods and cones distributed
cones - central
| rods - peripheral
131
what does high/low convergence mean
high convergence = more photoreceptors per ganglion cell
| low convergence = fewer photoreceptors per ganglion cell
132
do rods/cones have high or low convergence
cones - low convergence
| rods - high convergence
133
what effect does convergence have on vision
more convergence = increased sensitivity (low light), decreased acuity
134
how do we see colour
there are different opsin for different wavelengths (colours) of light
135
visual symptoms associated with raised ICP
```
transient blurred vision
double vision
loss of vision
papilloedema
pupillary changes
```
136
what are the three layers of the meninges
dura
arachnoid
pia
137
where is the sub-arachnoid space
between the arachnoid and Pia layers of the meninges
138
where does the dura mater get its nerve supply from
CNV
139
how does damage to CNIII manifest
```
paralysis of MR, IR, SR, IO
paralysis of parasympathetic innervation of sphincter of pupil
loss of pupillary light reflex
ptosis
eye turned inferolaterally
```
140
presentation of CNIV palsy
affected eye cannot move inferomedially
| diplopia when looking down
141
presentation of CNVI palsy
medial deviation of the affected eye
142
assessment of eye trauma should include
history of the incident
visual acuities
examination of eye (lids, conjunctiva, cornea, anterior segment, pupils, fundus)
use of fluorescein drops
143
what do fluorescein drops identify
areas of epithelial loss
144
what is hyphaema
blood in the anterior chamber
145
what is commotion retinae
bruised retina
146
what is sympathetic ophthalmia
trauma to one eye resulting in auto-immune reaction in both eyes
may lead to bilateral blindness
147
signs of penetrating foreign body
irregular pupil
shallow anterior chamber
localised cataract
gross inflammation
148
investigation of intra-ocular foreign body
x-ray
149
treatment of chemical burns
irrigation with at least 2 L of saline
| investigation
150
why does chloramphenicol easily penetrate the cornea
it is both lipophilic and hydrophilic
151
when is prednisolone acetate used
uninflamed cornea, post-operatively
152
when is prednisolone phosphate used
inflamed cornea, corneal disease
| when low dose steroids are required (limited permeability in uninflamed cornea)
153
what is the function of benzalkonium
preservative that enhances corneal penetration and disrupts lipid layer of tear film
154
how to prevent systemic absorption of topical steroids
punctual occlusion
155
anti-inflammatory agents used in the eye
steroids NSAIDs
anti-histamines
mast cell stabilisers
156
indications for steroids
post op cataracts
uveitis
prevention of corneal graft rejection
temporal arteritis
157
local side effects of steroids
cataract
glaucoma
exacerbation of viral infection
158
drugs used to treat glaucoma
```
prostanoids
beta blockers
carbonic anhydrase inhibitors
a2 adrenergic agonist
parasympathomimetic
```
159
example of intravitreal drugs
anti-VEGF
antibiotics in endophthalmitis
IO steroids
160
how do mydriatic drugs work
block parasympathetic supply to iris
161
side effect of ethambutol
optic neuropathy
162
pathogenesis of diabetic retinopathy
chronic hyperglycaemia > glycosylation of protein/basement membrane > loss of perocytes > microaneurysms > leakage/ischaemia
163
signs of non-proliferative diabetic retinopathy
micro aneurysms (dot and blot haemorrhages)
hard exudate
cotton wool patches
abnormalities of venous calibre
intra-retinal microvascular abnormalities
164
new retinal vessel growth in a diabetic patient is a sign of
proliferative diabetic retinopathy
165
why do diabetic patients lose vision
retinal oedema affecting the fovea
vitreous haemorrhage
scarring/traction retinal detachment
166
management of diabetic retinopathy
laser (PRP/macular grid)
| vitrectomy
167
features of hypertensive retinopathy
```
attenuated blood vessels - copper or silver wiring
cotton wool spots
hard exudates
retinal haemorrhage
optic disc oedema
```
168
cherry red spot is a sign of
central retinal artery occlusion
169
presentation of central retinal artery occlusion
sudden painless, profound loss of vision
170
presentation of central vein occlusion
sudden painless visual loss, range of visual loss
171
patient presents with headache, jaw claudication, malaise, raised PV and loss of vision
GCA (temporal arteritis)
172
extra ocular signs of thyroid eye disease
proptosis
lid retraction/lag/oedema/pigmentation
restrictive myopathy
173
ocular signs of thyroid eye disease
```
chemosis
injection
glaucoma
choroidal folds
optic nerve swelling
```
174
RA eye signs
dry eyes
scleritis
corneal melt
175
sjorgen's eye signs
dry eyes
176
Marfan's eye signs
conjunctivitis
| retinal detachment
177
stevens-johnson syndrome
symplepharon
| corneal ulcers
178
causes of sudden visual loss
```
vascular aetiology
vitreous haemorrhage
retinal detachment
ARMD wet type
closed angle glaucoma
```
179
vascular causes of sudden visual loss
occlusion of retinal circulation (artery/vein)
occlusion of optic nerve head circulation
haemorrhage from abnormal vessels (diabetes, wet ARMD)
retinal tear
180
signs of CRAO
relative afferent pupil defect
| pale, oedematous retina, thread-like vessels
181
causes of CRAO
carotid artery disease
| emboli from the heart (unusual)
182
management of CRAO
ocular massage id early presentation
establish source of embolus
assess and manage risk factors
183
variants of CRAO
branch retinal artery occlusion
| amaurosis fugax
184
what is amaurosis fugax
transient CRAO
185
symptoms of amaurosis fugax
transient painless visual loss
'like a curtain coming down'
lasts <5 mins with full recovery
186
treatment of amaurosis fugax
aspirin
187
causes of CRVO
atherosclerosis
hypertension
hyperviscosity
raised IOP
188
signs of CRVO
retinal haemorrhages
dilated tortuous veins
disc and macular swelling
189
treatment of CRVO
laser treatment of new vessels
anti-VEGF
address risk factors
190
occlusion of optic nerve head circulation is also known as
ischaemic optic neuropathy
191
which arteries become occluded in ischaemic optic neuritis
posterior ciliary arteries
192
presentation of ischaemic optic neuropathy
sudden profound visual loss
193
what are the two types of ischaemic optic neuropathy
arteritic (GCA)
| non-arteritic (athersclerotic)
194
arteritic ischaemic optic neuritis causes reversible blindness
true/false
false
| vision loss associated with GCA is irreversible
195
treatment of GCA
high dose steroids
196
signs and symptoms of vitreous haemorrhage
loss of vision
floaters
loss of red reflex
may see haemorrhage on fundoscopy
197
management of vitreous cause
management of cause
| vitrectomy if not resolving
198
signs and symptoms of retinal detachment
painless loss of vision
sudden onset flashes/floaters
may have RAPD
may see tear on ophthalmoscopy
199
management of retinal detachment
surgical
200
2 types of ARMD
wet
| dry
201
pathogenesis of wet ARMD
new blood vessels grow under the retina
| leakage causes build up of fluid/blood and eventually scarring
202
signs and symptoms of wet ARMD
rapid central visual loss
distorsion (metamorphopsia)
haemorrhage and exudate
203
treatment of wet ARMD
anti-VEGF
204
symptoms of closed angle glaucoma
painful, red eye
visual loss
nausea and vomiting
headache
205
treatment of closed angle glaucoma
medication to lower IOP
| laser iridotomy
206
causes of gradual visual loss
```
cataract
ARMD dry type
refractive error
glaucoma
diabetic retinopathy
```
207
symptoms of cataract
gradual decline in vision (hazy/blurred) that cannot be corrected with glasses
may get glare
208
management of cataract
surgical removal with intra-ocular lens implant
209
signs of symptoms of dry ARMD
gradual decline in vision
central vision missing (scotoma)
drusen (build up of waste products below RPE)
atrophic patches of retina
210
myopia
shortsighted
211
hypermetropia
longsighted
212
astigmatism
irregular corneal curvature
213
presbyopia
loss of accommodation with ageing
214
in myopia, light diverges before/after the retina
before
215
in hypermetropia light diverges before/after the retina
after
216
pathogenesis of open angel glaucoma
resistance to outflow of aqueous humour in trabecular network leading to build up of aqueous humour and raised IOP
217
symptoms of glaucoma
often asymptomatic
| may have visual loss
218
signs of glaucoma
cupped disc
visual field defect
may/may not have high IOP
219
papilloedema vs swollen optic disc
swollen optic disc = swelling due to any cause
| papilloedema = swollen disc due to raised ICP
220
bilateral optic disc swelling and suspected ICP may be due to
a space occupying lesion
221
CNII examination includes
```
ophthalmoscopy
VA
pupil exam
visual field assessment
colour vision
```
222
what is blepharitis
inflamed eyelids
223
what causes posterior blepharitis
meibomian gland disease
224
treatment of blepharitis
lid hygiene
tear drops
oral doxy 2-3 months
225
non-infective causes of conjunctivitis
allergic
chemical/drugs
skin disease) eczema
226
signs of conjunctivitis
```
red eye
discharge
papillae or follicles
sub conjunctival haemorrhage
chemosis (oedema)
pre-auricular glands (if viral)
```
227
papillae are associated with which type of conjunctivitis
bacterial
228
follicles are associated with which types of conjunctivitis
viral
chlamydial
drugs
229
keratitis affect which part of the eye
cornea
230
what are the three layers of the cornea
epithelium
strome
endothelium
231
symptoms of corneal ulcers
```
pain
photophobia
profuse lacrimation
vision may be reduced
red eye (around cornea)
```
232
treatment of scleritis
oral NSAIDs
oral steroids
steroid sparing agents
