Ophthalmology Flashcards
1
Q
cherry red spot at the macula
A
central retinal artery occlusion
2
Q
tear drop or blood level in sinus
A
blow out fracture
3
Q
failure to adduct in affected eye and contralateral nystagmus
A
internuclear opthalmoplegia (problem with medial longitudinal fasiculus in the brainstem)
4
Q
pain on eye movement
A
optic neuritis (common in MS)
5
Q
curtain coming down <5mins (painless temporary loss of vision)
A
amaurosis fugax
transient retinal ischaemia
6
Q
floaters and flashes of light, worsening of outer visual field. painless loss of vision partial curtain coming down >5mins
A
retinal detachement
7
Q
acute onset red eye, decreased visual acuity, photphobia, small fixed pupil, ciliary flush
A
anterior uveitis
8
Q
gritty
A
bacterial conjunctivitis or sub-tarsal foreign body
9
Q
watery, pain, pre-auricular lymph nodes
A
viral conjunctivitis
10
Q
silver/copper wiring
A
HTN eye disease
11
Q
loss of red reflex, eye red on ophthalmoscopy
A
haemorrhage
12
Q
new vessels and haemorrhage
A
ARMD wet
13
Q
follicular conjunctivitis
A
chlamydia
14
Q
pinpoint pupils
A
pontine lesion
15
Q
miosis, partial ptosis and loss of hemifacial sweating
A
horner’s syndrome (damage to sympathetic trunk)
16
Q
down out and dilated
A
damage to CN3/oculomotor
17
Q
roth spots
A
infective endocarditis
18
Q
brushfield spots
A
down’s syndrome
19
Q
scrambled egg/egg yolk appearance on macula
A
best disease
20
Q
Mechanism of a blow out fracture?
A
external force to the orbital cavity from a source with a bigger diameter than the orbit
rise in intraorbital pressure that causes fractures of the thinner/weaker medial wall or orbital floor
21
Q
What passes through the supraorbital notch and what does this innervate?
A
supraorbital nerve
forehead sensation
22
Q
What passes through the infraorbital foreamen?
A
infraorbital artery infraorbital nerve (maxillary nerve after it has past through the foreamen)
23
Q
What muscle closes the eye lids?
A
obicularis oculi
24
Q
What open the eye lids?
A
levator palperbrae suprioris
25
What controls the lacrimal gland?
CN VII
| Facial nerve
26
tarsus
eyelids
27
Where do the lacrimal puncta drain?
into nasolacrimal duct and eventually the inferior meatus
28
What is the colour portion of the eye?
iris
29
What are the 3 distinct layers of the eye?
fibrous layer
vascular or uveal layer
retina or photosensitive layer
30
What makes up the fibrous outer layer of the eye?
cornea 2/3 of refraction sclera
31
What makes up the uvea and function of each?
```
iris (pupil diameter)
ciliary body (made up of ciliary muscle- controls shape of lens and ciliary epithelium- secretion of aqueous humour (non-pigmented portion secretes vitreous humour)
choroid (nutrition and gas exchange)
```
32
Where is the anterior segment and what are its two chambers?
```
in front of the lens
anterior chamber (between cornea and iris)
posterior chamber (between iris and suspensory ligaments)
```
33
Where are muscles that move the eye ball attached?
to the sclera
34
What are the suspensory ligaments?
fibres that connect ciliary body to the lens
35
What do the anterior and posterior chambers contain?
aqueous humour
36
Where is the posterior segment of the eye and what does it contain?
behind the lens
| vitreous humour
37
What is the circulation of aqueous humour?
secreted by ciliary body into posterior chamber, nourishes lens and passes through pupil to anterior chamber. nourishes cornea reabsorbed into canal of schlemm
38
What is the fundus and what does it include?
interior surface of the eye opposite the lens
retina (layer that contains cells sensitive to light)
optic disk (head of the optic nerve, entry/exit point for blood vessels and axons)
macula (oval pigmented area near the centre of the retina)
fovea (centre of the macula, tiny pit, area of most acute vision)
posterior pole (retina portion between macula and optic disc)
39
What makes the blind spot?
optic disc
40
What is bayoneting of the vessels?
bending or kinking sharply as they pass over the edge of the cup
41
What are 5 common signs on fundoscopy of open angle glaucoma?
```
optic disc cupping
optic disc pallor
bayoneting vessels
cup notching
disk haemorrhages
```
42
How is aqueous humour reabsorbed?
drains through a sieve like trabecular meshwork (in front of the iris) into the scleral venous sinus (canal of schlemm) into the blood stream
43
Where is the canal of schlemm?
at the iris-corneal angle
44
What structures help focus light on the retina?
cornea and lens
45
What is the macular responsible for and why?
central high resolution colour vision has the greatest density of cones
46
Where is the optic disc located?
nasaly
47
Where does the ophthalmic artery arise from?
first branch of internal carotid distal to cavernous sinus
48
What are dural venous sinuses?
venous channels between enveloped by dura matter below the periosteum
receive blood from internal and external veins of the brain and receive CSF from subarachnoid space
empty into internal jugular veins
49
What artery and vein supply/drain the retina?
central artery of the retina (end artery)
| central vein of the retina
50
What are the muscles of the eye?
s,i,m,l rectus
| s,i oblique
51
What are the nerves that innervate the eye muscles?
LR6 (abducent)
SO4 (trochlear)
AO3 (occulomotor)
52
What is the relationship between the orbital axis and the visual axis and why is this relavent?
in their primary position the gaze of eye (visual axis) is directed forward
the orbital axis lies lateral 22 degrees
when testing muscles/nerve supply to the eye you have to line up gaze to the plane of the muscle being tested so as to isolate that muscle
53
Testing of the muscles in the right eye?
sr io
lr mr
ir so
54
what causes intorsion?
SO
55
What cause extorsion?
IO
56
What muscles are involved in pure elavation?
SR
| IO
57
What muscles are involved in pure depression?
IR
| SO
58
What holds the eye just above the floor of the orbit?
suspensory ligament
59
What are the 3 division of the trigeminal nerve?
V1 opthalmic
V2 maxillary
V3 mandibular
60
What are the afferent and efferent components of the blink/corneal reflex?
afferent (sensory) trigeminal V1 fibres detect stimulus on cornea
efferent (motor) facial nerve CNVII stimulates orbicularis oculi
61
How do sympathetic fibres reach the head and neck?
exit T1-L2
reach sympathetic trunk and synapse in cervical ganglion
post synaptic axons enter internal and external carotid nerve and travel on surface of internal and external carotid areteries
62
What CNs have parasympathetic fibres?
3, 7, 9, 10
63
parasympathetic CN supply to the eye?
CNIII (oculomotor)
64
What CN supplies parasymathetic innervation to lacrimal gland, submandibular gland and sublingual gland?
CNVII (facial)
65
What CN supplies parasympathetic innervation to parotid gland?
CN IX (glossopharyngeal)
66
What supplies motor to levator palpebrae superioris?
CNIII (occulomotor)
67
What muscle and NS is involved in pupillary dilation?
dilator pupillae fibres radially arranged in the iris
| sympathetic nervous system (dim light, fight/flight, illness)
68
What muscle and NS is involved in the pupillary constriction?
sphincter pupillae fibres arranged circularly in middle of iris
parasympathetic nervous system (bright light, rest and digest)
69
What is tropicamide and how does it work?
myadriatic drug that cuases pupil dilation by blocking the parasympathetic receptors on pupillae restrictor muscle
70
Pin point pupil
opiate drugs (stimulate parasympathetic nervous system)
71
fixed dilated blown out pupil?
CNIII pathology (inhibition of parasympathetic constriction of pupil)
72
What is the afferent and efferent components of the pupilary response?
afferent (sensory): CNII (optic detects light)
| efferent (motor to phincter pupillae muscles) bilateral CNIII (oculomotor) direct reflex and consensual reflex
73
Why does touching 1 cornea elicit blinking in both eyes?
the afferent/sensory signal is sent to both sides of the brain stem so the efferent signal is sent to both eyes
74
What controls the accommodation reflex?
parasympathetic nervous system
75
What happens in near objects?
ciliary muscles contracts (parasymathetic) decreases tension on the suspensory ligaments and fattens the lens
76
What happens in distant objects?
ciliary muscle relax (no parasympathetic) which increases tension on the suspensory ligaments and makes the lens more spherical
77
What features do you look for in accommodation reflex?
bilateral pupil constriction
| bilateral convergence
78
What is blood supply to eye?
2 circulations
| retinal and uveal
79
What produces CSF?
choroid plexus
80
What are rods responsible for?
vision at low light levels, no colour vision
81
What are cones responsible for?
vision at high light levels, colour vision, high spatial acuity
82
What is the fauvea?
highest density of cones
83
What are the wavelengths that activate our photoreceptors?
visible light
blue- short wave cone
green- middle wave cone
red- long wave cone
84
What are the layers of the meninges?
dura matar
arachnoid mater
pia mater
85
Where are lumber punctures done?
L3/4
| L4/5
86
Where does subarachnoid space end?
S2
87
Is the optic nerve covered by meninges?
yes
