Ophthalmology Flashcards

1
Q

What are the 3 layers of the eyeball?

A
  1. Fibrous
  2. Vascular
  3. Inner
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2
Q

What does the inner layer of the eyeball include?

A

The retina

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3
Q

What are the anterior and posterior chambers of the eye?

A
  • 2 fluid filled chambers in the eye
  • They are filled with clear aqueous humour that protects the eye
  • This is drained via the trabecular meshwork
  • Obstruction of this drainage results in glaucoma
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4
Q

What is the main fluid part of the eyeball?

A

Vitreous body

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5
Q

What is the name and function of CN II

A
  • Optic
  • Sight
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6
Q

What is the name and function of CN III?

A
  • Oculomotor
  • Innervation of IO, MR, SR, IR muscles
  • Elevation of the eyelid
  • Miosis and accommodation
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7
Q

What is the name and function of CN IV?

A
  • Trochlear
  • Innervation of SO muscle
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8
Q

What is the name and function of CN VI?

A
  • Abducens
  • Innervation of LR muscle
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9
Q

What is the name and function of CN VII?

A
  • Facial
  • Closure of eyelids
  • Lacrimation
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10
Q

What vessels provides arterial blood supply to the eyeball? What is a key branch and why?

A
  • Ophthalmic artery
  • Central artery of the retina
  • Occlusion of this can quickly result in blindness
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11
Q

What vessels carry out venous drainage of the eyeball?

A

Superior and inferior ophthalmic veins

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12
Q

What neurotransmitter and division of the autonomic nervous system cause pupil constriction?

A
  • Parasympathetic
  • Acetylcholine
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13
Q

What neurotransmitter and division of the autonomic nervous system cause pupil dilation?

A
  • Sympathetic
  • Adrenaline
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14
Q

What is considered normal vision? What do the numbers mean? What would indicate better and worse vision?

A
  • 6/6 (in america this = 20/20)
  • It means the patient can read something at 6 metres that the average person can read at 6 metres
  • 6/9 (worse vision) - the patient can read something at 6 metres that the average person can read at 9
  • 6/4 (better vision) - the patient can read something at 6 metres that the average person can read at 4
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15
Q

What is diabetic retinopathy

A

Where blood vessels in the retina are damaged by hyperglycaemia

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16
Q

What is seen in diabetic retinopathy when visualising the retina?

A
  • Microaneurysms
  • Venous beading
  • Neovascularisation
  • Blot haemorrhages
  • Hard exudates (lipid deposits in the retina)
  • Cotton wool spots (sign of nerve fibre damage)
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17
Q

Complications of diabetic retinopathy

A
  • Retinal detachment
  • Vitreous haemorrhage
  • Optic neuropathy
  • Cataracts
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18
Q

What is glaucoma?

A

Optic nerve damage caused by raised intraocular pressure

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19
Q

What are the 2 types of glaucoma?

A
  • Open angle glaucoma
  • Acute angle closure glaucoma
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20
Q

Which of the types of glaucoma is an ophthalmic emergency?

A

Acute angle closure glaucoma

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21
Q

What happens in open angle glaucoma?

A
  • There is an increase in resistance in the trabecular meshwork
  • This makes is more difficult for aqueous humour to flow through the meshwork and exit the eye
  • The pressure fluids slowly and results in slow onset glaucoma
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22
Q

What are features of open angle glaucoma?

A
  • Asymptomatic for a long time
  • Reduced peripheral vision
  • Tunnel vision
  • Gradual onset of fluctuating pain, headaches, blurred vision, halos around lights
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23
Q

What is the first line management of open angle glaucoma?

A
  • Prostaglandin analogue eye drops (e.g. latanoprost)
  • Increase uveoscleral outflow
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24
Q

What happens in acute angle closure glaucoma?

A
  • The iris bulges forward and seals off the trabecular meshwork
  • This prevents aqueous humour from being able to drain away
  • This leads to a continual build-up of pressure.
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25
How would a patient with acute angle closure glaucoma present?
- Severely painful red eye - Blurred vision - Halos around lights - Headache, nausea and vomiting
26
What features are typical of acute angle closure glaucoma on examination?
- Red-eye - Teary - Hazy cornea - Decreased visual acuity - Dilatation of the affected pupil - Fixed pupil size - Firm eyeball on palpation
27
What is the initial management of acute angle closure glaucoma?
- Lie the patient flat - Pilocarpine eye drops - Acetazolamide 500 mg orally - Give analgesia and an antiemetic if required
28
What is the MOA of pilocarpine and acetazolamide in acute angle closure glaucoma?
- Pilocarpine causes pupil constriction increasing the flow of aqueous humour - Acetazolamide is a carbonic anhydrase inhibitor, it decreases the production of aqueous humour
29
What is the definitive treatment of acute angle closure glaucoma?
Laser iridotomy - using a laser to make a hole in the iris to allow the aqueous humour to flow from the posterior chamber into the anterior chamber, this relieves pressure that was pushing the iris against the cornea and allows the humour the drain
30
Give 5 causes of Mydriasis
- Third nerve palsy - Raised ICP - Trauma - Stimulants e.g. cocaine - Anticholinergics
31
Give 5 causes of Miosis
- Horners syndrome - Cluster headaches - Argyll-Robertson pupil (in neurosyphilis) - Opiates - Nicotine
32
How does a third nerve palsy present?
- Down and out gaze - Ptosis - Dilated non-reactive pupil
33
Why does a third nerve palsy cause a dilated pupil?
The oculomotor nerve contains parasympathetic nerve fibres that normally stimulate pupil constriction
34
What can cause a third nerve palsy?
- Trauma - Tumour - Posterior communicating artery aneurysm - Cavernous sinus thrombosis - Raised ICP
35
What is the biggest risk factor for retinal detachment?
Retinal tear
36
What increases someones risk of a retinal tear?
- Older age - Diabetic retinopathy - Severe myopia (short sightedness)
37
How does retinal detachment present?
3 Fs: - Flashes - Floaters - Field changes
38
How can you group the causes of sudden loss of vision?
1. Vascular - Central retinal artery occlusion - Retinal vein occlusion 2. Inflammatory - Optic neuritis
39
What are 2 common causes of central retinal artery occlusion?
- Atherosclerosis - Giant cell arteritis
40
How does central retinal artery occlusion present?
Sudden painless loss of vision
41
What do you need to check for when investigating central retinal artery occlusion?
- An RAPD - Pale retina on funducopy - 'Cherry red' spot at the macular on fundoscopy
42
What is the long term managment of central retinal artery occlusion?
As the most common risk factor is atherosclerosis, long term management includes treating reversible risk factors (smoking, obesity, hypertension) and secondary prevention of CVD
43
How does retinal vein occlusion present?
Sudden painless loss of vision
44
What would you see on fundoscopy in retinal vein occlusion?
- Flame and blot haemorrhages - Optic disc oedema
45
Why are the similarities between the management of retinal vein occlusion and diabetic retinopathy?
Like in diabetic retinopathy, vein occlusion results in retinal damage. This results in the release of VEGF which stimulates the development of new blood vessels (neovascularisation). Like in diabetic retinopathy, these new vessels are weak and prone to bleeding. Treatments such as anti-VEGF injections aim to reduce these complications
46
Causes of painful red eye?
- Acute angle closure glaucoma - Scleritis - Anterior uveitis (iritis) - Keratitis (corneal inflammation) - Corneal abrasion - Conjunctivitis
47
What is anterior uveitis?
- Inflammation of the anterior chamber of the eye (iris and ciliary body) - Also called iritis
48
What conditions is anterior uveitis associated with?
Anterior uveitis is associated with HLA-B27 therefore... - Ank spondylitis - Reactive arthritis - UC/Crohn's - Behcet's disease - Sarcoidosis
49
How does anterior uveitis present?
- Acute - Ocular discomfit and pain - Photophobia (intense) - Red eye
50
What examination findings suggest anterior uveitis?
- Ciliary flush (ring of red spreading outwards) - Hypopyon (pus + inflammatory cells in the anterior chamber -> visible fluid level) - Pupil may be small and irregular (due to sphincter muscle contraction) - Visual acuity initial normal -> impaired
51
What is the management of anterior uveitis?
- Urgent opthal. r/v - Cycloplegics (dilate the pupil to relieve pain and photophobia) e.g. atropine, cyclopentolate - Steroid eye drops
52
What is scleritis? What is the most severe type?
- Inflammation of the sclera - Necrotising scleritis - call lead to perforation of the sclera
53
What are the causes of scleritis?
- Idiopathic - Associated with underlying systemic inflammatory condition - Infection (less common)
54
What systemic inflammatory conditions are associated with scleritis?
- RA ( this is because the connective tissue of the sclera is similar to that in joints) - Vasculitis (granulomatosis with polyangiitis) - SLE - Sarcoidosis RA is the most commonly associated condition
55
How does scleritis present?
- Red, inflamed sclera (can be localised or diffuse) - Congested vessels - Pain w eye movement - Photophobia - Epiphora - Reduced visual acuity
56
What is the management of scleritis?
- Urgent opthal. r/v - NSAIDs (normally first line) - Steriods (topical/systemic) - Immunosuppressive drugs for resistant cases (and to treat underlying associated disease)
57
What is episcleritis?
Inflammation of he episclera (the outermost layer of the sclera)
58
How does episcleritis present differently to scleritis?
- No photophobia - No discharge - Normal visual acuity - Often a patch of redness in the lateral sclera
59
What can you do to help differentiate between episcleritis and scleritis?
- Apply phenylephrine eye drops - This will case blanching of the episcleral vessels
60
What are the two types of conjunctivitis?
- Infective - Allergic
61
How does bacterial vs viral infective conjunctivitis present?
Bacterial: - Purulent discharge - Eyes stuck together in the morning Viral: - Serous discharge - Painful pre auricular lymph nodes
62
What is the management of infective conjunctivitis?
- Self-limiting - clears in 1-2 weeks without treatment - Abx - chloramphenicol drops, topic fusidic acid if pregnant - Don't wear contacts during episode
63
How does allergic conjunctivitis present?
- Watery discharge - Itchy eyes - Often in conjunction with hayfever but can occur alone
64
What is the first and second line management of allergic conjunctivitis?
- 1st - topical/systemic antihistamines - 2nd - topical mast-cell stabilisers e.g. sodium cromoglicate
65
What is blepharitis? What are the common causes?
Inflammation of the eyelid margins - Meibomian gland dysfunction (most common) - Seborrhoeic dermatitis - Staphylococcal infections
66
What is the function of the meibomian glands? What does meibomian gland dysfunction result in?
- Secrete oil onto the eye surface to prevent rapid evaporation of the tear film - Dry eyes -> irritation
67
How does blepharitis present?
- Bilateral symtoms - Grittiness and discomfort (particularly around eyelid margins) - Eyes may be sticky in the morning - Eyelid margins may be red
68
What is the management of blepharitis?
- Warm compress BD to soften lid margins - Artificial tears for symptoms relief if dry eyes
69
Causes of painless red eye?
- Subconjunctival haemorrhage - Conjunctivitis - Episcleritis - Blepharitis - Dry eyes
70
What is an RAPD?
Relative afferent pupillary defect - The affected pupil does not constrict as much as the normal pupil when performing the swinging light test - This is due to dysfunction of the retina or optic nerve
71
What are the common causes of an RAPD?
- Optic causes - optic neuritis - Retinal causes - retinal detachment, retinal ischaemia - Glaucoma - Trauma
72
What condition is optic neuritis typical of?
MS
73
What are the features of optic neuritis?
- Central scotoma - Painful eye movements - Impaired colour vision - An RAPD
74
What is strabismus?
Misalignment of the eyes
75
What is amblyopia?
- Lazy eye - When a more dominant eye is prioritised resulting in the other eye becoming progressively more disconnected and 'lazy'
76
What is latent vs manifest strabismus?
1. Latent - eyes become misaligned when not in use - Ends in phoria e.g. exophoria - Cover test - eye will move out when covered and in when uncovered 2. Manifest - eyes are always misaligned - Ends in tropia e.g. exotropia - Cover test - eye will correct when unaffected eye is covered
77
How is strabismus managed in children?
- The visual fields develop up to the age of 8 so it is important to treat children before then - Occlusion of the dominant eye will a patch or blurring drops forces the weaker eye to develop
78
Causes of ptosis
- Age related - Myasthenia gravis - Horner's syndrome - Third nerve palsy - Congenital
79
What is the most common cause of blindness in the UK?
Age-related macular degeneration (ARMD)
80
What is the macula?
- The central retina - It generates high-definition colour vision - It has four layers: - Choroid layer (base) - contains blood vessels that supply the macular - Bruch's membrane - Retinal pigment epithelium - Photoreceptors
81
What are RF for ARMD?
- Age - risk increases 3 fold for patients >75 - Smoking - FHx - RF associated with IHD e.g. HTN, DM
82
How can ARMD be classified?
- Dry macular degeneration (90% of cases) - Wet macular degeneration (aka neovascular macular degeneration)
83
What happens in wet ARMD?
- New vessels develop from the choroid layer and grow into the retina (neovascularisation) - These can leak fluid or blood -> oedema and faster vision loss
84
What stimulates the development of new vessels in wet ARMD?
Vascular endothelial growth factors (VEGF)
85
How does ARMD present?
- Gradual loss of central vision (faster in wet) - Reduced visual acuity - Crooked or wavy appearance to straight lines (metamorphopsia) - Worsening ability to read text
86
What examination findings indicate ARMD?
- Reduced visual acuity - Central scotoma - Drusen seen during fundoscopy
87
What are drusen?
- An important finding in AMD - Yellowish deposits of proteins and lipids between the retinal pigment epithelium and Bruch's membrane - A few small drusen can be normal in older patients - Frequent and larger drusen can be an early sign of MD
88
What investigations are used in ARMD?
- Slit lamp - Optical coherence tomography to view the layers of the retina - Fluorescein angiography in wet ARMD to see oedema and neovascularisation
89
What is the management of dry ARMD?
- No specific treatment - Rx involved monitoring and reducing the risk of progression by: - Avoiding smoking - Controlling BP - Some ev shows benefit of vitamin supplementation
90
What is the management of wet ARMD?
- Intravitreal anti-VEGF injections - Block VEGF and slow the development of new vessels - Pts have injections once/month
91
What happens in cataracts?
The lens of the eye gradually opacifies, this makes if more difficult for light to reach the retina -> reduced/blurred vision
92
What are RF for cataracts?
- Increasing age - Smoking - Increased alcohol consumption - DM - Trauma - Long term corticosteriods - Radiation exposure - Hypocalcaemia
93
How does cataracts present?
- Reduced vision - Faded colour vision - Glare - lights appear brighter - Halos around lights - Normally asymmetrical
94
What's a key examination finding in cataracts?
Absence of red reflex
95
What is the management of cataracts?
- No intervention if symptoms are manageable - Cataract surgery
96
Why might someone still have reduced visual acuity after cataract surgery?
- Cataracts can prevent detection of other pathology e.g. macular degeneration/diabetic retinopathy - These become apparent after cataract surgery
97
What are complications of cataract surgery?
- Posterior capsule opacification (thickening of lens capsule) - Retinal detachment - Posterior capsule rupture - Endophthalmitis
98
Whta is Endophthalmitis?
- Inflammation of the inner contents of the eye - Usually caused by infection, is a rare complication of cataract surgery - Can lead to vision loss - Treated with intravitreal antibiotics
99
What are common eyelid disorders?
- Stye - Chalazion - Entropion - Ectropion
100
What is the management of styes?
- Hot compress - Analgesia - Topical abx if associated conjunctivitis
101
What is a chalazion?
- Aka meibomian cyst - Occurs when a meibomian gland becomes blocked and swells - Presents with swelling of the eyelid that is (normally) not tender
102
What is the management of chalazion?
Warm compresses and gentle massage of the eyelashes to encourage drainage
103
Entropion: 1. What is it? 2. What are the risks? 3. What is the managment?
1. When the eyelid turns inwards with the lashes pressed against the eye 2. Pain, corneal damage, ulceration 3. Taping down the eyelid + lubricating eyedrops, definitive management is surgical
104
Ectropion: 1. What is it? 2. What are the risks? 3. What is the managment?
1. When the eyelid turns outward, exposing the inner aspect 2. Exposure keratopathy 3. Lubricating eyedrops, more significant cases require surgery
105
What is trichiasis?
Inward growth of the eyelashes
106
What is pre-orbital cellulitis? What are the causes? What is the risk?
- Superficial infection anterior to the orbital septum - Superficial tissue injury e.g. chalazion, insect bite - Periorbital cellulitis can progress to orbital cellulitis
107
What is orbital cellulitis?
An infection affecting the fat and muscles posterior to the orbital septum, within the orbit but not involving the globe
108
What usually causes orbital cellulitis?
An upper respiratory tract infection from the sinuses
109
What age group is most commonly affected by orbital cellulitis?
- Children - mean age of hospitalisation = 7-12
110
How does orbital cellulitis present?
- Redness and swelling around eye - Severe ocular pain - Visual disturbance - Proptosis - Opthalmoplegia - Eyelid oedema
111
What symptoms differentiate orbital from pre-orbital cellulitis? What investigation can help differentiate?
- Reduced visual acuity - Proptosis - Opthalmoplegia - CT with contrast - inflammation of the orbital tissues deep to the septum
112
What is the management of pre-orbital cellulitis?
- Systemic abx (oral/IV) - Vulnerable pts (e.g. children) my require admission for monitoring
113
What is the management of orbital cellulitis?
- Emergency admission - IV abx - Surgical drainage if abscess forms
114
What is keratitis?
Inflammation of the cornea
115
What are possible causes of keratitis?
- Viral infection (herpes simplex) - Bacterial infection - Fungal infection - Contact lens-induced acute red eye (CLARE) - Exposure keratitis (caused by inadequate eyelid coverage)
116
What is the most common cause of keratitis?
- Herpes simplex virus (HSV) - Called herpes simplex keratitis
117
How does keratitis present?
- Red eye - Photophobia - Foreign body - gritty sensation - Hypopyon may be seen
118
What is the management of keratitis?
- Stop using contact lenses until symptoms have improved - Topical abx - quinolones first line - Cycloplegic for pain relief - cyclopentolate
119
What are complications of keratitis?
- Corneal scarring - Perforation - Endophthalmitis - Visual loss