Ophthalmology Flashcards
(100 cards)
1
Q
Name the structures light travels through to make an image on the retina
A
Tear film-> conjuntiva->cornea-> aqueous humour-> lens-> vitreous-> retina
2
Q
Name the layers of the retina
A
Nerve fibre layer
Photoreceptors
Retinal pigment epithelium
3
Q
Difference between two types of photoreceptor cells
A
Rods: diffuse, black and white and dim settings
Cones: colour vision, mainly in macula
4
Q
Name the 7 bones that make up the orbit
A
Frontal, zygomatic, maxillary, lacrimal, ethmoid, palatine, sphenoid
5
Q
Name the extraocular muscles supplied by the oculomotor nerve
A
Superior rectus, Inferior rectus, medial rectus, inferior oblique and levator palpebrae superioris
6
Q
Name the extraocular muscles supplied by CNIV
A
Superior oblique
7
Q
Name the extraocular muscles supplied by CNVI
A
Lateral rectus
8
Q
What happens in 3rd nerve palsy?
A
‘Blown pupils’
Fixed down and out position of eyes
ptosis on affected side
9
Q
Name the layers of the eyelid from anterior to posterior
A
Skin Orbicularis oculi muscle Tarsal plate and Muller's muscle Meibonian glands Conjunctiva
10
Q
What nerve supplies sensation to the eyelids?
A
CN V1 (ophthalmic)
11
Q
Describe the drainage route for tears
A
Puncta Canaliculi Lacrimal sac Nasolacrimal duct Nasopharyngeal canal
12
Q
What does the tear film consist of?
A
Ant->post
Lipid (from meibonium gland)
->aqueous (from lacrimal gland)
->mucin (from conjunctiva)
13
Q
What is the average thickness of the cornea?
A
550µm
14
Q
Name the layers of the cornea (ant->post)
A
Epithelium Bowman's Stroma Decemet's Endothelium
15
Q
What does parasympathetic innervation do to the pupil and lens?
A
Contracts sphincter pupillae to constrict pupil
Relaxes zonules of ciliary body, lens becomes more rounded (accommodation)
16
Q
Describe the passage of aqueous humour
A
From ciliary body
Through pupil into anterior chamber and angle
Through trabecular meshwork to canal of Schlemm
Into veins
17
Q
Where do the optic nerves synapse?
A
Lateral Geniculate Bodies in the occiptal lobe
18
Q
Which fibres do not cross at the optic chiasm?
A
The temporal retinal branches
19
Q
What is emmetropia?
A
No refractive error
Light is focussed on the retina
20
Q
What is myopia?
A
Short sightedness, light focusses in front of retina
21
Q
How do you correct myopia?
A
Concave lens
22
Q
What is hyperopia?
A
Long sightedness
Light is focussed behind the retina
23
Q
How do you correct hyperopia?
A
Convex lens
24
Q
What is presbyopia?
A
The lens hardens with age, less able to accommodate
Need reading glasses for near vision
25
Name 5 classes of ocular antihypertensives
```
Beta blockers
Carbonic anhydrase inhibitors
a2-agonists
Muscarinic agonists
Prostaglandin analogues
```
26
Name a beta blocker eye drop and SEs
Timolol
| Bronchospasm, bradycardia
27
Name a carbonic anhydrase inhibitor used in ophthalmology and SEs
Acetazolamide
| Deranged renal function
28
Name an a2-agonist and SEs
Brimonidine
| Dry mouth, hypotension
29
Name a muscarinic agonist and SEs
Pilocarpine
| Sweating, bradycardia
30
Name a prostaglandin analogue and SEs
Latanoprost
| Asthma, lash growth
31
Which ocular antihypertensives reduce aqueous production?
Beta blockers, carbonic anhydrase inhibitors, a2-agonists
32
Which ocular antihypertensives increase aqueous outflow
a2-agonists, muscarinic agonists, prostaglandin analogues
33
Name 2 lubricants
Hypromellose, viscotears
34
What are the classes of drugs used for pupil dilation
Myadratics (a1-agonists- phenylephrine)
| Cycloplegics (muscarinic antagonists- tropicamide)
35
Name 4 anti-inflammatory eye drugs
Steroids (prednisolone)
Mast cell stabilisers (sodium cromoglycate)
Antihistamines (Antazoline)
NSAIDs (diclofenac)
36
Name the main antibiotics used in ophthalmology
Chloramphenicol (grey baby, used for conjunctivitis)
| Ofloxacin (used for corneal ulcers)
37
Name the most common antivirals
Aciclovir, valciclovir
38
What drugs can be given as an intravitreal injection?
Steroids (dexamethasone)
Anti-microbial (vancomycin)
Anti-VEGF (ranibizumab)
39
What are anti-VEGF injections used to treat?
Neovascularisation in wet macular degeneration and proliferative diabetic retinopathy
40
How do you go about an eye examination?
```
IMAFRO
Inspection
Movement
visual Acuity
visual Fields
pupillary Reflexes
Ophthalmoscopy
```
41
What does inspection in the ophthalmic examination include?
Facial asymmetry
Skin
Eyelids (evert upper eyelid, crusting, droopiness)
Conjunctiva (colour, foreign bodies)
Cornea (ulcers, abrasions, foreign bodies)
42
What does 6/60 vision mean?
What a normal person can see at 60m, the patient can see at 6m
43
What is the pinhole used for?
To limit refractive error
| To assess underlying vision issues
44
What is LogMAR?
Like Snellen, 6/6 is 0.0, 6/60 is 1
45
Colour vision is measured with?
Ishihara plates
46
What is the screening visual field test?
Ask pt to look at your nose, is any of my face missing?
47
What do you test in a more advanced visual field test?
Colour desaturation and blind spot mapping
48
What do you test in pupillary reflexes?
Look at both pupils (size and shape)
Direct and consensual reflexes
Swinging light test for relative afferent pupillary defect
49
Describe steps of ophthalmoscopy
Wash hands, introduce, explain, gain consent
Low brightness, middle size light, check on palm forst
Gain idea of patients refractive error (green for long-sighted)
Darken room, ask pt to fixate on wall
Right hand, right eye
Red reflex from arm's distance away
Place free hand behind patient
Find optic disc (colour, contour, cupping)
Main vessels, haemorrhages, exudate
Macula (look directly at light)
50
Additional eye examination tests?
Lid lag for Grave's disease
| Cover-uncover test for Strabismus
51
What is acute angle closure glaucoma?
Iris adheres to lens, obstructs outflow of aqueous, raised intraocular pressure
52
Symptoms of acute angle closure glaucoma
Red severely painful eye, nausea and vomiting, halos around light, blurring of vision
53
Signs of acute angle closure glaucoma
Eyeball hard on palpation
Unreactive semi-dilated pupil
Redness around hazy cornea
Cornea cloudy (oedematous)
54
Management of acute angle closure glaucoma
```
Constrict pupil: pilocarpine
Reduce aqueous production: IV acetazolamide
Reduce inflammation: Prednisolone drops
Laser iridotomy?
Lie pt supine
```
55
2 causes of CNIII palsy
| Differences
Posterior communicating artery aneurysm: blown pupil, thunderclap headache
Ischaemia secondary to diabetic neuropathy: pupil sparing
56
What is orbital cellulitis?
Painful swollen eyelid, fever
Staph or strep infection
Life threatening as can move to brain, can cause 2º glaucoma
Reduced eye movements, proptosis
57
How do you treat orbital cellulitis?
IV broad spectrum antibiotics
58
What is temporal arteritis?
Inflammation of the arteries supplying the optic nerve
| Necrosis and visual loss
59
Symptoms of temporal arteritis
Sudden unilateral blurred vision. headache, tender scalp
| Jaw claudication, malaise, weight loss, night sweats
60
Diagnosis: thunderclap headache, fixed dilated down and out pupil, ptosis
Posterior communicating artery aneurysm
61
Diagnosis: sudden blurred vision, headache, tender scalp
Temporal arteritis
62
Management of temporal arteritis
IV steroids and bone protection
63
Blood results for temporal arteritis
Raised ESR/CRP/low Hb/raised platelets
64
What could cause an absent red reflex in children?
Retinoblastoma or congenital catarcts
65
What can cause congenital cataracts?
```
TORCH infection intrauterine exposure
Toxoplasmosis
Other (syphilis, varicella-zoster, parvovirus B19)
Rubella
Cytomegalovirus (CMV)
Herpes infections
Intrauterine steroid exposure
```
66
What is endophthalmitis?
Infection in the vitreous or aqueous of the eye
Usually post-operative and sight threatening
Onset minutes to hours
May see hypopyon as well as red eye and discharge
Worst case scenario loss of eye
67
What does distortion hint at?
Macula issues
68
Symptoms of retinal detachment
```
Floaters
Flashes
Curtain being drawn across vision
Distortion if macula is involved
If due to traction in diabetes it is gradual vision loss
```
69
What is a central retinal artery occlusion and what does it look like under a fundoscope?
Thromboembolic blockage causing retinal infarction
Painless sudden visual loss
RAPD
Retina pale with cherry red spot of macula
70
Treatment central retinal artery occlusion?
Rule out temporal arteritis
Screen for cardiovascular risk factors
Fluorescein angiography
Aim to reduce intra-ocular pressure (acetazolamide, aspirin, hyperventilate)
71
What is a retinal vein occlusion and symptoms?
Thrombosis of retinal veins, branch is more common than central
Causes painless visual loss unilaterally, retinal flame haemorrhages and cotton wool spots. Vitreous haemorrhage, swollen optic disc, tortuous vessels
72
Treatment of retinal vein occlusion
Investigate for cardiovascular risk factors
Autoimmune disease/clotting disorders/glaucoma screening
Monitor regularly
Low dose aspirin
Treat risk factors
73
Which is worse in the eye: acid or alkali?
| How do you manage?
Alkali is more destructive
| Wash eye until tear pH is back to normal
74
What must you do in penetrating ocular trauma?
Xray for foreign bodies in eye
75
What would hypertensive retinopathy look like?
Retinal damage due to chronic hypertension
Cotton wool spots, flame haemorrhages, papilloedma is advanced/malignant hypertension
• Acute ischaemia in choroid
• Optic disc swelling
Chronic hypertension
• Arteriosclerosis (copper wiring)
• AV nipping
76
How can you tell the difference between hypertensive retinopathy, vein occlusion and diabetic retinopathy?
Diabetic retinopathy has hard yellow exudates
77
Definition and symptoms of thyroid eye disease
```
Autoimmune
Anti-TSH receptor antibodies target extraocular muscles
Irritable red eyes
Aching
Pain on eye-movement
Double vision
```
78
Examination and investigations for thyroid eye disease
```
Eye movements
Proptosis
Lid retraction
Lid lag on downward gaze
Systemic signs
Thyroid function tests, anti TSH antibodies, CT scan for extraocular swelling
```
79
How does Sjögren's syndrome manifest in the eye?
Autoimmune destruction of lacrimal and salivary glands
Associated with rheumatoid and SLE
Burning gritty eyes, dry mouth, difficulty swallowing
Treat with eye lubricants and underlying autoimmune condition
80
What is uveitis associated with?
```
Ankylosing spondylitis
Psoriatic arthritis
IBD
Sarcoidosis
Syphilis
```
81
Treatment of uveitis
Steroids
| Dilate pupil
82
Whats more common, scleritis and episcleritis?
Episcelritis
83
What can scleritis lead to?
Globe perforation
84
Differences between scleritis and episcleritis
Scleritis: subacute severe pain, immobile hyperaemic vessels, associated with rhematoid/SLE
Episcleritis: common, acute mild pain, mobile hyperaemic vessels, self limiting
85
Name 5 non emergency diagnoses for red eye
```
Subconjunctival haemorrhage
Dry eyes
Conjunctivitis
Corneal abrasion
Keratitis
```
86
Name 6 causes for acute visual loss
Central retinal artery occlusion
Acute angle closure glaucoma
Optic neuritis
Vitreous haemorrhage (retinal vein occlusion/diabetic retinopathy)
Anterior ischaemic optic neuropathy (after temporal arteritis)
87
4 causes of gradual vision loss
Refractive errors
Cataracts
Age related macular degeneration
Primary open angle glaucoma
88
3 causes of flashes/floaters
Posterior vitreous detachment
Migraine with aura
Retinal detachment
89
4 subacute causes of abnormal eyelids
Blepharitis and chalazion
BCC
Herpes zoster
Entropion and ectropion
90
2 causes of irregular pupils
Horner's
| Adie's
91
What can be found on an everted eyelid that differentiates between 2 diagnoses?
Follicles: viral
Papillae: allergic, pink
92
Treatment of chlamydial conjunctivits
Oral azithromycin, swabs and refer to GUM
93
Corneal abrasion treatment
Chloramphenicol drops
94
What is optic neuritis?
Demyelination of the optic nerve
1st presentation of MS
Blurred optic disc, RAPD, reduced visual acuity
95
What is age related macula degeneration?
Dry: retinal atrophy with drusen
Wet: neovascularisationm haemorrhages distorting macula. Can be treated with anti-VEGF
96
What does a cupped disc mean?
Primary open angle glaucoma
| Progressive optic neuropathy
97
Treatment of chalazion
Massage, eyelid hygeine
Topical antibiotics if infected
Surgical excision
98
What is the most common eyelid neoplasm?
BCC
99
What is amblyopia?
Squint causing double vision
Brain ignores one side-> abnormal development if not corrected by age 7
Corrected with temporary patching of good eye
100
What visual loss can you have and still drive a car?
6/12 in at least 1 eye (read reg plate at 20m)
| Have visual field of 120º horizontally
