Ophthalmology Brief Flashcards
what is the anterior chamber in the eye
the space between the cornea and the iris - it is filled with aqueous humour
what is the posterior chamber in the eye
it is the space between the iris and the lens - it is filled with aqueous humour
where does aqueous humour get produced and where does it drain?
it is produced by the ciliary body and it flows around the lens under the iris, through the anterior chamber, through the trabecular meshwork and into the canal of Schlemm where it enters general circulation
describe the pathophys of open angle glaucoma
- gradual resistance through the trabecular meshwork
- aqueous humour slowly builds up in anterior and posterior chambers
- intraocular pressure builds, giving slow and chronic onset of glaucoma
describe the pathophys of acute angle glaucoma
- the iris bulges forward and seals of the trabecular meshwork from the anterior chamber
- this prevents aqueous humour from draining
- this is a continual build up of pressure
- opthalmology emergancy
what happens to the optic nerve in glaucoma
- increased intraocular pressure causes cupping of the optic disc
- in the centre of a normal optic disc is an optic cup
- usually less than half the size of the optic disc
- in glaucoma the optic cup enlarges due to pressure
- this is called cupping
- an optic cup greater than 0.5 the size of the optic disc is abnormal
risk factors for open angle glaucoma
increasing age
family history
black ethnic origin
nearsightedness (myopia)
presentation of open angle glaucoma
- rise in pressure is asymptomatic for a long time so often diagnosed by routine screening during eye checks
- affects peripheral vision first gradually until tunnel vision
- can present with gradual onset of
- fluctuating pain
- headaches
- blurred vision
how do you measure intraocular pressure
- non contact tonometry
- puff of air
- less accurate but gives helpful estimate for screening
- goldmann applanation tonometry
- gold standard
- device on end of slip lamp that makes contact with cornea and applies pressure
diagnosis of open angle glaucoma
goldmann applanation tonometry
fundoscopy
visual field assessment
management of open angle glaucoma
- prostaglandin analogue eye drops are first line
- latanoprost
- other options
- beta blockers
- timolol
- carbonic anhydrase inhibitors
- dorzolamide
- sympathomimetics
- brimonodine
- beta blockers
- trabeculectomy surgery if eye drops are ineffective
- creates a bleb under the conjunctiva where aqueous humour can be reabsorbed
risk factors for acute angle glaucoma
increasing age
female sex
family history
chinese and east asian ethnic origin
rare in black people
which medications can precipitate acute angle-closure glaucoma
- adrenergic medications
- e.g. noradrenaline
- anticholinergic medications
- e.g. oxybutynin
- tricyclic antidepressants
- e.g. amitryptyline
presentation of acute angle glaucoma
severely painful red eye
blurred vision
halos around lights
associated headache nausea and vomiting
examination findings in acute angle glaucoma
red eye
teary
hazy cornea
decreased visual acuity
dilatation of the affected pupil
fixed pupil size
firm eyeball on palpation
initial management of acute closed-angle glaucoma
- ambulance
- lie patient on back without a pillow
- pilocarpine eye drops
- constricts pupil and causes ciliary muscle contraction
- opens pathway of flow of aqueous humour to trabecular meshwork
- oral acetazolamide
- reduces production of aqueous humour
- analgesia and antiemetic if required
secondary care of acute closed-angle glaucoma
- pilocarpine
- oral acetazolamide
- timolol
- beta blocker reduces production
- dorzolamide
- reduces production
- brimonidine
- reduces production and increases uveoscleral flow
- laser iridotomy is usually required
- makes hole in iris to facilitate flow
what is the most common cause of blindness in the UK
age related macular degeneration
what is the key finding seen during fundoscopy in macular degeneration
drusen
these are yellow deposits of proteins and lipids
what are the types of age related macular degeneration and which is more common and which has the worse prognosis
wet and dry
90% of cases are dry
10% of cases are wet
wet has the worse prognosis
three features common in both wet and dry AMD
atrophy of retinal pigment epithelium
degeneration of the photoreceptors
drusen
pathophys of wet amd
new vessels grow from choroid layer to the retina
these leak fluid and cause oedema
more rapid loss of vision
caused by vascular endothelial growth factor
risk factors for amd
age
smoking
white or chinese ethnic origin
family history
cvd
presentation of AMD
gradual worsening of central visual field
reduced visual acuity
crooked or wavy appearance of straight lines
wet can present more acutely with symptoms coming on over days and progress to full vision loss by 2-3 years
amd findings on examination
reduced acuity on snellen chart
scotoma (central patch of vision loss)
fundoscopy - drusen
management of dry amd
- no specific treatment
- manage lifestyle factors
- avoid smoking
- control blood pressure
- vitamin supplementation slows progression
management of wet amd
- anti-vegf medications
- ranibizumab
- bevicizumab
- pegaptanib
- these injected into vitreous chamber once a month
- need to be started within 3 months of symptom onset to be beneficial
pathopys of diabetic retinopathy
7 features
- hyperglycaemia leads to damage of the retinal small vessels
- blot haemorrhages
- hard exudates of lipids on retina
- microanueurysms
- venous beading
- wein walls no longer straight and look like string of sausages
- cotton wool spots
- nerve fibre damage on retina causes these fluffy white patches
- intraretinal microvascular abnormalities (IMRA)
- dilated capillaries that act as shunt between arterial and venous vessels
- neovascularisation
- due to growth factors
how do you classify diabetic retinopathy broadly
- depending on whether new blood vessels have developed it is either:
- proliferative
- neovascularisation
- vitrious haemorrhage
- non-proliferative
- can develop into proliferative
- proliferative
how do you classify non proliferative diabetic retinopathy based on severity
- mild:
- microaneurysms
- moderate:
- microaneurysms
- blot haemorrhages
- hard exudates
- cotton wool spots
- venous beading
- severe
- blot haemorrhages
- microaneurysms in 4 quadrants
- venous beading in 2 duadrants
- IMRA in any quadrant
complications of diabetic retinopathy
- retinal detatchment
- vitreous haemorrhage
- bleeding into vitreous humour
- rebeosis iridis
- new blood vessel formation in the iris
- optic neuropathy
- cataracts
management of diabetic retinopathy
laser photocoagulation
anti-vegf medications such as ranibizumab and bevacizumab
vitreoretinal surgery may be required in severe disease
signs associated with hypertensive retinopathy
hypertensive retinopathy signs
6 things
- silver wiring or copper wiring
- walls of arterioles thickened and sclerosed increasing light reflection
- arteriovenous nipping
- arterioles compress veins where they cross
- cotton wool spots
- ischaemia and infarction of the retina causes damage to nerve fibres
- hard exudates
- caused by damaged vessels leaking lipids into the retina
- retinal haemorrhages
- damaged vessels rupture
- papilloedema
- ischaemia to the optic nerve results in swelling and blurring of the disc margins
what is the classification system for hypertensive retinopathy
- keith wagener classification
- stage 1: mild narrowing of the arterioles
- stage 2: focal constriction of blood vessels and AV nicking
- stage 3: cotton-wool patches exudates and haemorrhages
- stage 4: papilloedema
risk factors for cateracts
increasing age
smoking
alcohol
diabetes
steroids
hypocalcaemia
presentation of cateracts
- symptoms usually asymmetrical as both eyes are affected seperately
- slow reduction in vision
- progressive visual blurring
- starbursts around light
- loss of red reflex
- lens appears grey or white when testing red reflex
name a complication of cateract surgery
endopthalmitis - inflammation of the inner contents of the eye normally caused by infection
treated with intravitreal abx injected into the eye
causes of mydriasis
- 3rd nerve palsy
- holmes adie syndrome
- raised ICP
- congenital
- trauma
- stimulants such as cocaine
- anticholinergics
causes of miosis
horner’s syndrome
cluster headaches
argyll-robertson pupil (neurosyphilis)
opiates
nicotine
pilocarpine
third nerve palsies cause
ptosis (supplies levator palpebrae superioris)
dilated non-reactive pupil (contains parasympathetic fibres that innervate sphincter muscles of iris)
divergent strabismus (down and out)
causes of third nerve palsy
- full third nerve palsy (caused by compression therefore referred to as surgical third)
- idiopathic
- tumour
- trauma
- cavernous sinus thrombosis
- posterior communicating artery aneurysm
- raised ICP
- if pupil is spared it’s because parasympathetic fibres are spared and suggests a microvascular cause
- diabetes
- hypertension
- ischaemia
what is horner’s syndrome
ptosis
miosis
anhidrosis
enopthalmos
what causes horner’s syndrome
- damage to the sympathetic nervous system supplying the face
- depending on the anhidrosis then the location of the damage can be identified
- central lesions cause anhidrosis of the arm and trunk as well as face
- pre-ganglionic lesions cause anhidrosis of the face
- post-ganglionic lesions do not cause anhidrosis
what is the journey of the sympathetic nerves that supply the head
- arise from spinal cord in chest as pre-ganglionic nerves
- enter sympathetic ganglion at base of neck
- exit as post-ganglionic nerves
- post-ganglionic nerves travel to the head running alongside the internal carotid
causes of central, pre and post ganglionic causes of horner’s
and how to remember this
- 4S for Sentral
- Stroke
- multiple Sclerosis
- Swelling (tumours)
- Syringomyelia (cyst on spinal cord)
- 4T for Torso (pre-ganglionic)
- Tumour (pancoast)
- Trauma
- Thyroidectomy
- Top rib (cervical rib growing above the clavicle
- 4C for Cervical (post-ganglionic)
- Carotid aneurysm
- Carotid artery dissection
- Cavernous sinus thrombosis
- Cluster headache
what is argyll robertson pupil
specific finding in neurosyphilis
constricted pupil that accomodates when focussing nearby object
does not react to light
often irregularly shaped
“accomodates but does not react” made it known as prostitutes pupil also due to it’s relation to syphilis
what is blepharitis
inflammation of the eyelid margins - can be associated with dysfunction of the meibomian glands
management of blepharitis
- hot compresses and gentle cleaning
- lubricating eye drops
what is a stye
how are they treated
- hordeolum externum
- infection of glands of Zeis
- sebacious glands at the base of eyelashes
- or infection of glans of Moll
- sweat glands at the base of the eyelashes
- infection of glands of Zeis
- hordeolum internum
- infection of meibomian glands - tend to be deeper
- may be under eyelid
- treated with hot compresses and analgesia
- consider chloramphenicol topically if associated with conjunctivitis or persistent
what is a chalazion
how is it treated
- aka meibomian cyst
- this is when a meibomian gland becomes blocked and swells up
- typically not tender but can be tender and red
- treated with hot compress and analgesia
- consider chloramphenicol if acutely inflamed
- rarely, surgical drainage may be necessary
what is an entropian
how is it managed
- where eyelid turns inwards with lashes agains eyeball
- can result in corneal damage
- initial management
- tape down to stop it turning inwards
- essential to use regular lubricating eye drops
- difinitive management
- surgery
what is an opthalmic ectropian
- eyelid turns outwards with the inner aspectof the eyelid exposed
- can lead to exposure keratopathy
- mild cases may not need treatment
- regular lubricating eye drops may be needed
- surgery may be needed for severe cases
what is trichiasis
- inward growth of eyelashes
- can lead to corneal damage
- management by epilation
- recurrent cases may need electrolysis or laser treatment
what is periorbital cellulitis
- skin infection in front of the eye
- swelling redness and hot skin around the eyelids and eyes
- treatment with IV or oral abx
- can develop into orbital cellulitis so vulnerable people may need admission
- NOT THE SAME AS ORBITAL CELLULITIS which is sight and life threatening
- CT can be used to differentiate
what is orbital cellulitis
- infection around the eyeball that involves the orbital septum
- medical emergency that requires
- admission
- IV antibiotics
- maybe surgical drainage if there is an abscess
how to differentiate orbital and periorbital cellulitis
- orbital cellulitis has these features that periorbital cellulitis does not
- pain on eye movement
- reduced eye movement
- changes in vision
- abnormal pupil reacctions
- proptosis
what are the three types of conjunctivitis
bacterial
viral
allergic
causes of painless red eye
conjunctivitis
episcleritis
subconjunctival haemorrhage
causes of painful red eye
glaucoma
anterior uveitis
scleritis
corneal abrasions or ulcerations
keratitis
foreign body
traumatic or chemical injury
how long does it normally take conjunctivitis to resolve
normally resolves without treatment in 1-2 weeks
what is the uvea
involves the iris, ciliary body and choroid
what is anterior uveitis
- inflammation and immune infiltration of the anterior chamber of the eye
- usually autoimmune
- can be acute or chronic
- chronic is more granulomatous (has more macrophages)
- chronic if lasting more than 3 months
what conditions is acute anterior uveitis associated with
- HLA B27 related conditions
- ankylosing spondylitis
- inflammatory bowel disease
- reactive arthritis
chronic anterior uveitis is associated with
sarcoidosis
syphilis
lyme disease
tuberculosis
herpes virus
anterior uveitis presentation
- dull aching painful red eye
- pain on movement
- ciliary flush
- reduced visual acuity
- floaters
- photophobia
- pain on movement
- excessive lacrimation
- hypopyon
- collection of white blood cells in the anterior chamber
- seen as yellowish fluid collection settled in front of the lower iris
managment of anterior uveitis
- same day assessment by an opthalmologist
- steroids
- immunosuppressants
- DMARDs
what is episcleritis
benign and self-limiting inflammation of the episclera
presentation of episcleritis
- typically not painful but there may be mild pain
- segmental redness
- foreing body sensation
- watering of eye
- no discharge
management of episcleritis
- usually self-limiting and recovers in 1-4 weeks
- simple analgesia
- safetynetting advice
what is scleritis
inflammation of the full thickness of the sclera
more serious than episcleritis
not usually caused by infection
most severe type is called necrotising scleritis which can lead to perforation of the sclera
systemic conditions associated with scleritis
- associated systemic condition in around 50% of patients presenting with scleritis
- rheumatoid arthritis
- systemic lupus erythematosus
- inflammatory bowel disease
- sarcoidosis
- granulomatosis with polyangiitis
presentation of scleritis
severe pain
pain with eye movement
photophobia
eye watering
reduced visual acuity
abnormal pupil reaction
tenderness to palpation of the eye
if a corneal abrasion is associated with the use of contact lense there may be infection with _______
pseudomonas
how do you diagnose corneal abrasions
fluorescein stain collects in abrasions and ulcers showing up yellow/orange
management of corneal abrasions
simple analgesia e.g. paracetamol
lubricating eye drops
chloramphenicol eye drops if infection suspected
safetynetting
what is keratitis
inflammation of the cornea
what are the different causes of keratitis
- viral: herpes simplex
- bacterial: pseudomonas or staphylococcus
- fungal: candida or aspergillus
- contact lense acute red eye (CLARE)
- exposure keratitis
what is the most common cause of keratitis
herpes simplex keratitis
diagnosis of keratitis
fluorescein staining will show a dendritic corneal ulcer
slit lamp examination
swabs and scrapings can be used to isolate the virus using viral culture or PCR
managment of herpes keratitis
aciclovir - topical or oral
ganciclovir eye gel
corneal transplant may be needed after infection has resolved to treat scarring
what may cause a subconjunctival haemorrhage
- strenuous activity such as heavy coughing, weight lifting or straining when constipated.
- can also be caused by trauma to eye
- most are idiopathic but there are some risk factors to ask about
- hypertension
- bleeding disorders (thrombocytopenia)
- whooping cough
- medications (warfarin, NOACs, antiplatelets)
- NAI
management of subconjunctival haemorrhage
harmless and resolve without any treatment in 2 weeks
investigate any predisposing features
what happens in retinal detatchment
retina seperates from choroid underneith
usually due to a retinal tear that allows vitreous fluid to get under the retina and fill the space between the retina and the choroid
because the retina relies on the vessels of the choroid for its blood supply this is a sight threatening emergency
risk factors for retinal detatchment
- posterior vitreous attachment
- diabetic retinopathy
- trauma to the eye
- retinal malignancy
- older age
- family history
presentation of retinal detatchment
painless
peripheral vision loss - sudden
blurred vision
flashes and floaters
management of retinal detatchment
- patients with painless flashes and floaters should have a detailed assessment of the retina by someone with the appropriate skillset
- three options to reattach retina
- vitrectomy
- replace vitreous body with oil or gas
- scleral bulking
- silicone buckle in sclera causes outer eye to indent and bring choroid in to meet retina
- pneumatic retinopexy
- inject a gas bubble into vitreous body and position so retina flattens against choroid
- vitrectomy
what happens in retinal vein occlusion
- the central retinal vein runs through the optic nerve and is responsible for draining blood from the retina
- four branches come together to form the central retinal vein
- thrombosis in of one of these causes problems in that area
- thrombosis in the central retinal vein causes problems with the whole retina
- blood will pool in the retina causing:
- macular oedema
- retinal haemorrhages
- VEGF release –> neovascularisation
presentation of retinal vein occlusion
sudden painless loss of vision
risk factors for retinal vein occlusion
hypertension
high cholesterol
diabetes
smoking
glaucoma
systemic inflammatory conditions such as SLE
diagnosis of retinal vein occlusion
- fundoscopy has characteristic findings:
- flame and blot haemorrhages
- optic disc oedema
- macula oedema
management of retinal vein occlusion
- immediate referral to opthalmologist
- laser photocoagulation
- intravitreal steroids
- dexamethasone intravitreal implant
- anti-VEGF therapies (e.g. ranibizumab, bevacizumab)
in diabetic retinopathy, cotton wool spots represent areas of:
retinal infarction
what are the stages of non-proliferative diabetic retinopathy
- Mild NPDR
- 1 or more microaneurysm
- Moderate NPDR
- microaneurysms
- blot haemorrhages
- hard exudates
- cotton wool spots, venous beading/looping and intraretinal microvascular abnormalities (IRMA) less severe than in severe NPDR
- Severe NPDR
- blot haemorrhages and microaneurysms in 4 quadrants
- venous beading in at least 2 quadrants
- IRMA in at least 1 quadrant
what is the marcus-gunn pupil
- relative afferent pupillary defect
- the affected and normal eye appear to dilate when the torch is moved from the unaffected eye to the affected eye
- causes
- lesion anterior to the optic chiasm
- retinal detachment
- optic neuritis
- lesion anterior to the optic chiasm
what are the pathways of the pupillary light reflex
- afferent
- retina –> optic nerve –> lateral geniculate body –> midbrain
- efferent
- edinger-westphal nucleus (midbrain) –> oculomotor nerve
how does glaucoma affect vision
starts in the peripheries leading to tunnel vision
acuity can be affected but this is less common
young woman with high BMI, headache and visual symptoms:
think idiopathic intracranial hypertension
eye pain out of proportion with clinical presentation, contact lens and recent freshwater swimming - which is the causative organism
acanthamoeba
accounts for 5% of cases
what is central scotoma
a blind spot in the centre of your vision
three diseases associated with optic neuritis
MS - most common
diabetes
syphilis
what is hutchinson’s sign
a shingles rash on the tip or the root of the nose - representing the dermatome of the nasociliary nerve - strongly associated with ocular involvement
what test can differentiate episcleritis and scleritis
phenylepherine drops blanch conjunctival and episcleral vessels but not scleral ones
therefore if the redness improves after phenylepherine, a diagnosis of episcleritis can be made
how is anterior uveitis treated
steroid eye drops and cycloplegic eye drops such as atropine
cycloplegic means paralysis of ciliary muscles of eyes
bilateral gritty eyes - think:
blepharitis
is there screening for glaucoma
there is a strong hereditary component of glaucoma
those with a first degree relative should have annual screening from the age of 40
how do you manage a patient in GP with an organic foreign body in their eye e.g. grass seed
refer immediately to opthalmology due to infection risk
what are the features of papilloedema
- venous engorgement: usually the first sign
- blurring of the optic disc margin
- elevation of optic disc
- loss of the optic cup
- Paton’s lines: concentric/radial retinal lines cascading from the optic disc
what is papilloedema
Papilloedema describes optic disc swelling that is caused by increased intracranial pressure. It is almost always bilateral.
causes of tunnel vision
- papilloedema
- glaucoma
- retinitis pigmentosa
- choroidoretinitis
4 most common causes of sudden painless loss of vision
- ischaemic/vascular
- includes:
- occlusion of central retinal artery
- occlusion of central retinal vein
- includes:
- vitreous haemorrhage
- retinal detatchment
- retinal migraine
what is hyphema
pooling or collection of blood inside the anterior chamber of the eye
what is the most serious complication of hyphema
blood blicking drainage of aqueous humour and leading to glaucoma
what’s mydriasis
dilation of the pupil
central renal artery occlusion
- sudden unilateral visual loss
- thromboembolism from atherosclerosis or temporal arteritis
- features
- afferent pupillary defect
- cherry red spot
- pale retina
management of dry armd
zinc and anti-oxidant vitamin therapy
that’s it
treatment for wet armd
anti-VEGF agents such as ranibizumab, bevicizumab and pegaptanib
what is hypermetropia
long sightedness
use the words HYPERMETROPIA and MYOPIA to fill these spaces
acute angle glaucoma is associated with _______
primary open angle glaucoma is associated with _____
acute angle glaucoma is associated with HYPERMETROPIA
primary open angle glaucoma is associated with MYOPIA
