Ophthalmology Flashcards
(118 cards)
1
Q
What is an relevant afferent pupillary defect (RAPD) and how is it tested for?
A
Comparing the paradoxical pupil dilation, when light is shone in one side, pupil constriction may happen less in both eyes than compared when light is shone in the other eye
Tested using the swinging torch test to compare the level of constriction
2
Q
If an RAPD is present, what pathology does this suggest?
A
Pathology in the optic nerve on the side which causes less constriction. This could be due to:
- large retinal detachment
- central retinal artery or vein occlusion
- optic neuritis
3
Q
When measuring visual acuity, what does 6/6 mean or 6/12?
A
6/6: they can see at 6 metres what they should be able to see at 6 metres
6/12: they can see at 6 metres what they should be able to see at 12
4
Q
What is the driving test legal standard for visual acuity?
A
6/12
5
Q
If the patient struggles with the visual acuity test using a snellen chart, how can you adapt the test?
A
Bring the chart closer
Use fingers - get patient to tell you how many fingers you’re holding up
Use hand movement - ask which hand is moving
Use light - can they perceive light
6
Q
How is using pin holes useful when testing visual acuity?
A
It allows for refractive errors by only letting light through the centre of the lens so the image should be focused
Means that ophthalmologists can determine if the problem is due to a refractive error (which are resolved at opticians) and an eye problem
7
Q
Which drugs are used to dilate eyes in opthalmascopy?
A
Tropicamide (most common)
Cyclopentolate
Phenylephrine
8
Q
What are the 3 C’s to consider when visualising the optic disc?
A
Cup - cup to disc ratio (increased ratio is known as cupping)
Contour - check borders are well defined
Colour - pink/orange is healthy, pale/yellow suggest nerve damage
9
Q
What is a normal cup to disc ratio of the optic disc?
A
Normal ratio: 0.3
When the cup to disc ratio is greater this can suggest the fibres are lost so the cup in the middle gets greater in size
10
Q
In myopia, where does the focused image lie in retrospect to the retina?
A
Anterior to the retina
11
Q
What type of lens are used to correct myopia?
A
Concave, diverging lens
This focuses the image back onto the retina
12
Q
In hyperopia, where does the focused image lie in comparison to the retina?
A
Behind the retina
13
Q
How is hyperopia (long-sightedness) managed?
A
With convex, converging lens
14
Q
What is the visual acuity standards for lorry and bus drivers?
A
Must have a visual acuity of 6/7.5 in best eye and at least 6/60 is other eye
Must have horrizontal visual field of at least 160 degrees
15
Q
What is the most common cause of visual loss in the elderly?
A
Age-related macular degeneration (AMD)
16
Q
What is the pathophysiology of AMD?
A
Undigested lipid products accumulate in the retinal pigment epithelium
These accumulate under the retina in the macula as yellow lesions called drusen, accumulate in bruch’s membrane
Changes in the macula, leads to problems with central vision
17
Q
What are the two types of drusen?
A
Hard drusen - small, spread out, people get some as they age, don’t cause visual problems (however the more you have the greater the risk of developing soft drusen)
Soft drusen - small, cluster together, associated with AMD
18
Q
What type of drusen is associated with AMD?
A
Soft drusen
As they get larger, they can cause bleeding and scarring in the cells in the macula
19
Q
How does age related macular degeneration usually present?
A
Blurring of central vision
Difficulty seeing detail e.g, small print
Increased sensitivity to light
20
Q
What are the two types of AMD?
A
Dry (90% of cases) - gradual loss of central vision over time
Wet (10% of cases) - sudden changes to central vision, majority of patients have dry AMD previously
21
Q
What is the pathophysiology of wet AMD?
A
Cells of the macula stop working
The eye undergoes angiogenesis to fix problem
New blood vessels growing int eh wrong place causes swelling and bleeding underneath the macula
22
Q
What are the risk factors for dry AMD?
A
Increasing age Female gender Smoking Hypertension Previous cataract surgery
23
Q
How is AMD managed?
A
No treatment available
Conservative management - some evidence of zinc and anti-oxidant vitamins A, C and E to help slow progression of disease
24
Q
How is wet AMD managed?
A
Using anti-vascular endothelial growth factor (Anti-VEGF)
This stops the new blood vessels from forming
25
What is glaucoma?
Group of eye diseases where you get intraoccular hypertension (increased pressure in the eye)
This can damage the optic nerve and lead to blindness
26
What is the normal intraoccular pressure of the eye?
10-20mmHg
27
What is the pathophysiology of gluacoma?
Build up of aqueous humor fluid in the eye
This is either due to increased production or decreased drainage
This increase of aqueous humour increases the intraoccular pressure and causes compression of the retinal blood vessels, causing degeneration of the optic nerve
28
What are the two types of glaucoma?
Primary open angle - where there is a reduction of aqueous outflow through the trabecular meshwork leading to increased pressure (this happens gradually over a long period of time)
Acute angle closure - where the iris is pushed forward against trabecular meshwork, closing the angle so that aqueous fluid cannot drain
29
What are the risk factors for primary open angle glaucoma?
```
Increasing age
Ethnicity - black Africans at increased risk
Family history
Diabetes
Myopia
```
30
How does primary open angle gluacoma present?
Usually painless
Happens over a long period of time
Loss of vision which starts peripherally
31
What are the risk factors for acute angle closure glaucoma?
Hypertropia (longsightedness)
| Sex - women have longer and shallower anterior chambers
32
How does acute angle closure glaucoma present?
```
Sudden onset of red and painful eye
Blurred vision
Nausea and vomiting - due to increased pressure
Headache
Abdominal pain
```
33
How is glaucoma managed?
Eye drops - to reduce intraoccular pressure
Laser trabeculoplasy - used to open up trabecular meshwork in open angle glaucoma
Iridotomy - laser which makes holes in iris, used to treat closed angle glaucoma
34
What kind of eye drops are used to decreased intraoccular pressure in glaucoma?
Lantanprost (prostaglandin analogue) - increases outflow of aqueous humor
Timolol (beta blocker) - reduces blood supply to cililary body, to reduce production of aqueous humor
Brinxolamide (carbonic anhydrase inhibitor) - inhibition of this enzyme slows production of aqueous humor
Pilocarpine (alpha adrenergic angonist) - contracts cililary muscle, causing trabecular meshwork to open
35
After someone has had an episode of acute closed angle glaucoma, how would you then manage the other eye?
Need to treat the other eye prophylacticly to prevent condition occurring in the other eye in the future
Done using peripheral iridotomy
36
Why should tropicamide be carefully used in patients with primary open angle glaucoma?
Dilating the eyes can cause a narrowing of the draining angle
37
What are the rules surrounding gluacoma and driving?
Patients should inform the DVLA if they have glucoma, which will then conduct their own specific tests to see if their eyes meet the current driving standards
38
How might glaucoma present on examination?
```
Normal visual acuity
Reduced visual peripheral fields
Cupping seen on fundoscopy - increased cup to disc ratio
Optic disc pallor on fundoscopy
Bayoneting of vessels seen on fundoscopy
```
39
Patients recently diagnosed with gluacoma should inform which people?
DVLA - to check if eyes meet standards
| Family - as glaucoma has genetic component so relatives should get their eyes screened by local optician
40
What piece of medial equipment is used to measure intraoccular pressure?
Tonometer
41
How does central retina artery occlusion present?
Sudden, painless loss of vision to one eye
Vision reduced to light perception only
Pupil barely reactive to light
Cherry red spot on fundoscopy
42
What is the cherry red spot?
During central retina artery occlusion the retina becomes Ischaemic
However choroidal circulation remains - this can be seen as the cherry red spot
This is present over the central fovea as this is where the retina is present
43
What are the risk factors for central retinal artery occlusion?
```
Diabetes
Hypertension
Hypercholesterolaemia
Vascular disease
Smoking
```
44
What other acute disease do you need to rule out in elderly patients presenting with symptoms of retinal artery occlusion?
Giant cell arteritis
45
How does retinal detachment present?
Sudden onset of floaters
Associated shadows
Painless
Normal vision
46
What are the risk factors for retinal detachment
```
Trauma
Myopia (short sightedness) - as patients have larger eyeballs so retina is thinner at the periphery
```
47
How does orbital cellulitis present?
Painful eye
Proptosis
Periorbital infalmmation and swelling
Reduction in eye movements
Can have previous conjunctival infection
Patients may have systemic symptoms and fever
48
What is are the complications of orbital cellulitis?
Infection spreading to the brain and causing brain abscess
| Can cause blindness
49
What are the common causative organisms of orbital cellulitis?
Staphylococcus
| Streptococcus
50
What investigations should be done in a patient presenting with orbital cellulitis?
Blood cultures - ?sepsis
Conjunctiva swab
Full blood count - ?sepsis
Orbital scan (MRI or CT) - infection can come from ethmoid sinus
51
What is a hypopyon?
Accumulation of white blood cells in the anterior chamber of the eye
Presents as an inflamed eye with a white “fluid level” in the anterior chamber
52
What are the 2 types of infective endophthalmitis?
Endogenous - due to septicaemia, more common in patients on ITU/HDU, or who have indwelling catheters
Post operative - infection of the eye following occular surgery
53
What is conjunctivitis?
Inflammation of the outermost layer of the eye
Caused by infection or allergy
Usually mild
54
How does conjunctivitis present?
```
Red and sore eyes (severe pain points to something more serious)
Blood shot eyes
Gritty eyes
Mucoid discharge
Normal visual acuity and relative pupils
```
55
What are the main causes of conjunctivitis?
Bacterial
Viral
Chlamydia
Allergic
56
How is conjunctivitis managed?
Remove any discharge using clean cotton wool and hot water
Cold compress - to cool eyes down
Avoid contact lenses until 48 hours after resolution of symptoms
57
How can you reduce the transmission of conjunctivitis?
Wash hands regularly
Don’t share pillows
Don’t wash eyes
58
What eye drops can be used to help manage bacterial conjunctivitis?
Chloramphenicol - given for up to 1 week
59
What is the presentation of herpes simplex keratitis?
Primary infection in early life, remains latent and can cause recurrent keratitis
Most infections cause mild fever, malaise and URTI
Blephritis and conjunctivitis may develop but are mild
Appearance of dendritic Ulster can be see in ophthalmoscopy
60
How does bacterial keratitis present?
```
Severe pain
Purulent discharge
Corneal ulcer
Visual loss
Hypopyon
```
61
What are the risk factors for developing bacterial keratitis?
Dry eye
Trauma
Contact lens wearer
Topical steroid use - as this can cause immunosupression
62
What is herpes zoster opthalmicus (opthalmic shingles)
Shingles in the opthalmic division of the Trigeminal nerve
63
How does opthalmic shingles present?
Pain
Vesicles in the distribution of the ophthalmic nerve
Swelling of eye
Keratitis
64
How does anterior uveitis present?
```
Eye pain - usually a dull ache which is worse when focusing
Red eye
Sensitivity to light
Blurred vision
Floaters
Loss of peripheral vision
```
65
How is anterior uveitis managed?
Steroids eye drops (prednisolone acetate) - to reduce inflammation in the eye
Mydriatic eye drops (cyclopentolate) - to dilate pupil and reduce the pain
66
What is posterior synechaie?
What condition is a risk factor for this?
Where the iris sticks to the lens
Anterior uveitis
67
What eye drops can be given to help visualise areas of epithilial loss in the eye?
Fluorescein (sodium fluorescein) - doesn’t stain intact corneal epithelial, only stains the deeper corneal stroma, so it highlights the area of epithlial loss
Orange water soluble dye - this is visualised using a cobalt blue filter which causes the dye to fluoresce a bright green colour
68
How is bacterial keratitis managed?
Frequent topical broad-spectrum antibiotics
69
How can you tell the difference between bacterial and viral conjunctivitis?
Viral conjunctivitis usually associated with a more watery discharge
70
What rheumatology conditions are associated with scleritis?
Granulomatosis with polyangiitis
| Rheumatoid arthritis
71
How does scleritis present?
Severe pain in eye
Infalmmation of the eye
Blurred vision
Increased sensitivity to light (photophobia)
72
What type of organism is most likely to cause bacterial kerititis in contact lens wearers?
Pseudomonas aeruginosa
73
What are the risk factors for orbital cellultis?
```
Childhood - children aged 7-12 most at risk
Previous sinus infection
Lack of hib B vaccination
Recent eyelid infection
Ear or facial infection
```
74
How is orbital cellulitis managed?
Admission to hospital for IV antibiotics
75
What other medication conditions are associated with anterior uveitis?
Any HLA-B27 linked conditions:
- ankylosing spondylitis
- reactive arthritis
- ulcerative colitis, crohns diesease
76
What is a cataract?
Opacification of the lens
The lens becomes cloudy and makes it difficult for light to reach the retina
This causes reduced/blurred vision
77
What are the risk factors for cataracts?
```
Increasing age (most common cause)
Smoking, alcohol
Trauma
Diabetes
Long term steroids
```
78
How do cataracts typically present?
Gradual onset reduced vision
Faded colour vision
Glare - lights appear brighter than usual
Halos around lights
79
What is the main sign of cataracts on examination?
Defect in the red reflex (as cataracts will prevent light from getting to the retina)
80
How are cataracts managed?
In early stages - encourage glasses, contact lens’s to optimise vision
In later stages - when visual impairment is present and they are impacting on quality of life, patients can chose to have corrective surgery (replacing the lens with an artificial one)
81
What are the signs of horners syndrome?
Miosis (small pupil)
Ptosis (drooped eyelid)
Endophthalmos (sunken eye)
82
How does belpharitis usually present?
Bilateral eye symptoms
Grittiness and discomfort
Eyes may be sticky in the morning
83
How would central retinal vein occlusion present?
Sudden painless loss of vision
| Severe retinal haemorrhages seen in fundoscopy (looks like cheese and tomato pizza)
84
How is herpes zoster ophthalmicus managed?
Oral aciclovir treatment for 7-10 days
| Treatment should ideally be started within 72 hours of onset
85
How is blephritis managed?
Hot compresses twice a day
| Lid hygiene - mechanical removal or debris from lid margins using cotton wool dipped in boiled water and baby shampoo
86
What is hutchinson’s sign?
Vesicles extending to the tip of the nose in herpes zoster opthalmicus
87
How does a 6th nerve palsy present?
Problem with the lateral rectus muscle
Patient will get double vision when looking in the direction that the palsy is at e.g, if right lateral rectus is affected will get double vision when looking to the right
88
What are the different causes of a 6th nerve palsy and how would you differentiate between them
Vasculitis - in patients with diabetes and hypertension
Raised ICP - papilloedema may be present
Cavernous sinus thrombosis - due to bacterial infection e.g, sinusitis causing blood clot which compresses CN6 in cavernous sinus
Demyelinating disease - investigate if other signs present
89
How does a 3rd nerve palsy present?
Ptosis on affected side
Affected eye is down and out (as the only eye muscles still working are superior oblique and lateral rectus)
Pupil may be dilated on the opposite side
90
What is the significance of opposite pupil dilation in a 3rd nerve palsy?
Parasympathetic system within CN3 travels along outside of the nerve
If this isn’t working, it suggests the nerve is being compressed
This could point towards compression from an aneurysm or a tumour
Urgent neuroimaging is required
91
What are the causes of a CN3 palsy?
Vasculitis - in patients with diabetes and HTN
Aneurysms - CN3 travels close to circle of willis where berry aneurysms are common
Tumours
92
How does a 4th nerve palsy present?
Problem with superior oblique muscle
| Affected eye will move up and medially (nasal upshot)
93
What are the main causes of a 4th nerve palsy?
Vasculitis - in patients with diabetes and hypertension
Congenital - many children are born with a congenital palsy of CN4, but develop stronger muscles to compensate
Trauma - CN4 is more susceptible to trauma
Tumours
94
What is a blowout fracture?
A fracture of the inferior orbital floor
Can occur due to trauma e.g, being hit in the eye - this is because the inferior orbital floor is a weaker bone which tends to give way first in trauma due to raised pressure in the orbit
95
How does a blowout fracture present?
History of trauma
Double vision (diplopia) - this is because orbital fat and muscle become trapped in the fracture causing double vision
Sunken eye
Bruising and swelling
Infra-orbital parasthesia - maxillary branch of trigeminal nerve affected
96
What is the management of an inferior orbital (blowout) fracture?
Refer to maxillofacial surgery
Advise patient not to blow nose - as trauma has caused communication between orbit and sinuses, if they blow nose then bacteria can enter the orbit
Broad spectrum antibitoics - to prevent orbit infection
97
How can myasthenia gravis present in the eyes?
Autoimmune disease affecting skeletal muscles
| If it affects the extraocular muscles then it can cause ptosis or diplopia
98
How is diplopia managed?
Patching affected eye
Prisms - glasses fitted with prisms which can be adjusted as the palsy recovers
Surgical intervention - to realign the eyes
99
What are the rules surrounding diplopia and driving?
Must stop driving and inform DVLA straight away
Can return to driving after period of adaption or if diplopia has resolved
Cannot hold group 2 license (HGV, lorries, buses) - even if diplopia is resolved
100
If diplopia from a CN palsy is suspected to be of a microvascular cause, how is this managed?
Referral to orthopists
| Monitor as an outpatient
101
When would you warrant urgent neuroimaging in the context of a CN palsy causing diplopia?
If there were multiple cranial nerves affected
In younger patients - as the cause is less likely to be vasculitis
If there is any papillodema - this points towards raised ICP
In the context of a CN3 palsy with an opposite dilated pupil - this could be due to an aneurysm or tumour due to location
102
Which dilating drops are used to visualise the eye in ophthalmoscopy in children?
Cyclopentolate
103
What does leukocoria mean in children?
White pupil
| It means the red reflex has been lost
104
What are the causes of leukocoria in children?
Retinoblastoma - this needs to be excluded immediately
Congenital cataract
Intraoccular infection - e.g, nematode endophtalmitis
Vitreous opacity
Coats disease
105
What age group is retinoblastoma most common?
In children under the age of 3
106
What is the pathophysiology of retinoblastoma in children?
Malignant transformation of primitive retinal cells before they differentiate
Primitive retinal cells disappear within the first few years of life, which is why the tumour is usually only seen before the age of 3
107
What are the two types of retinoblastoma?
Heritable (germline) (40%) - due to RB1 gene
| Non-heritable (60%) - tumour is unilateral, and does not predispose child to second monocular cancers
108
Which signs suggest a worse prognosis in retinoblastoma?
Optic nerve invasion
Massive choroidal invasion
Anterior chamber involvement
109
What percentage of congenital cataracts are bilateral?
2/3rds (66%)
A cause can be found in the majority of these cases - usually due to an autosomal dominant genetic Mu station
110
Which childhood conditions are associated with congenital cataract formation?
```
Down’s syndrome
Edwards syndrome
Cytomegalovirus
Rubella
Varicella
```
111
How are congenital cataracts managed?
Bilateral dense cataracts required early paediatric surgery (when the child is 4-6 weeks of age)
Bilateral partial cataracts - may not require surgery until later
Unilateral dense cataracts - urgent surgery (Within days) followed by aggressive anti-amblyopia therapy. Results are poor for this
112
What is retinopathy of prematurity (ROP)?
Proliferative retinopathy affecting premature infants of very low birth weight
These neonates are exposed to high oxygen concentrations when born
Premature infants have an incompletely vascularised retina which is susceptible to oxygen damage
This is because oxygen causes the production of VEGF to be down regulated, which halts blood vessel development
113
Which babies should be screen for retinopathy of prematurity?
The following Babies should be screen for ROP at 4-7 weeks postnatally:
- babies born before 31 weeks
- babies weighting less than 1.5kg
114
What are the complications of retinopathy of prematurity?
If left untreated, can lead to sight threatening conditions:
- vitreous haemorrhage
- retinal detachment
115
How is retinopathy of prematurity managed?
Laser photocoagulation - successful in 80% of cases
116
What is keratitis?
Inflammation of the cornea (the clear part covering the iris and the pupils)
117
What is endophthalmitis?
Infection inside of the eye involving the vitrous and/or aqueous humor
118
What is blepharitis?
Inflammation of the eyelids
| Due to blockage of the oil glands near the base of the eyelashes
