Ophthalmology Flashcards
what is the pathophysiology of acute angle closure glaucoma?
iris bulges forwards and seals off trabecular meshwork of anterior chamber, preventing aqueous humour from draining leading to increase in intraocular pressure => leads to further bulging of iris exacerbating angle closure
what are 6 risk factors for acute closed angle glaucoma?
Increased age
FHx
Female - 4x than M
Chinese/east asian ethnic origin
shallow anterior chamber
Hypermetropia - long sightedness
what are 3 meds that can precipitate acute closed angle glaucoma?
Adrenergic medications - noradrenaline
Anticholinergic meds - oxybutynin, solfenacin
Tricyclic antidepressants - amitryptyline
what are 5 presentations of acute closed angle glaucoma?
severe painful red eye
blurred vision
Halos around lights
Headache, nausea and vom
Pain worse on pupil dilation - watching TV in dark room
what are 5 signs of acute closed angle glaucoma on examination?
Red eye
Hazy cornea
decreased visual acuity
mid-dilated fixed size pupil
Hard eyeball on gentle palpation
what is the initial management of acute closed angle glaucoma in primary care? (4)
Lie patient on back without pillow
Pilocarpine eyedrops - 2% for blue eyes, 4% for brown eyes
Acetazolamide 500mg orally
Analgesia + antiemetics
WHAT IS PILOCARPINE?
used in management of acute closed angle glaucoma
acts on muscarinic receptors in sphincter muscle of iris causing pupil constriction (miotic agent) as well as causing ciliary muscle contraction
OPens pathway for flow of aqueous humour from ciliary body into trabecular meshwork
what is acetazolamide?
Used in treatment of acute closed angle glaucoma
carbonic anhydrase inhibitor - reduces production of aqueous humour
what is the dose of pilocarpine in blue eyes in acute closed angle glaucoma?
2%
what is the dose of pilocarpine in brown eyes in acute closed angle glaucoma?
4%
what is the dose of acetazolamide in acute closed angle glaucoma?
500mg PO
what is the definitive treatment of acute closed angle glaucoma?
laser iridotomy - making hole in iris with laser to allow for aqueous humour to drain from posterior to anterior chamber, relieving pressure
what are 6 secondary care options for management of acute closed angle glaucoma?
1 - Drops - pilocarpine, timolol, apraclonidine
1 - Acetazolamide - PO or IV
Definitive - laser peripheral iridotomy
Hyperosmotic agents - mannitol to increase osmotic gradient between blood and eye
Timolol - B Blocker which reduces production of aqueous humour
Dorzolamide - carbonic anhydrase inhibitor
Brimonidine - sympathomimetic that reduces aqueous humour production and increased uveoscleral outflow
what are 2 investigations for acute closed angle glaucoma?
Tonometry for elevated IOP
Gonioscopy - looking at angle
what is blepharitis?
inflammation of the eyelid margins
can be associated with dysfunction of meibomian glands or seborrhoeic dermatitis - can lead to styes, chalazions and conjunctavitis
what is the presentation of blepharitis?
bilateral, gritty, itchy, dry sensation in eyes worse in morning
Eyes may feel sticky in morning
Eyelid margins may be red/swollen
what is the management of blepharitis?
hot compress BD
Lid hygiene with cotton wool dipped in cooled boiled water
Artificial tears for symptom relief
what are the 2 different types of stye?
Hordeolum externum - infection of the glands of zeis or glands of moll - sebaceous or sweat glands at base of eyelashes - tender red possibly pussy lump at base of eyelashes
Hordeolum internum - infection of meibomian glands - deeper more painful, may point inwards towards eyeball underneath eyelid
what is the management of styes?
hot compress
analgesia
Chloramphenicol - topical ABx - may be considered with coexisting conjunctivitis
what is a chalazion?
blocked and swollen meibomian gland also called meibomian cyst
usually non-tender swelling of eyelid
what is the management of a chalazion
warm compress and gentle massage towards eyelashes to encourage drainage
rarely needs surgical drainage
what is entropion?
when the eyelid turns inwards and the eyelashes press on the eye
can cause corneal damage and ulceration
what is the management of entropion?
surgery
should have same day referral to ophthalmology if risk to sight
what is an eye ectropian?
when eyelid turns outwards exposing inner aspect
what can be a complication of an eye ectropion?
exposure keratopathy as the eyeball is exposed to air and not properly lubricated and protected
what is the management of eye ectropion?
regular lubricating eye drops
may require surgery - same day referral if risk to sight
what is trichiasis?
inward growth of the eyelash resulting in pain - can cause corneal damage and ulceration
what is the management of trichiasis?
removal of affected eyelashes
if recurrent may require electrolysis, cryotherapy or laser treatment to prevent regrowth
same day referral to ophthalmology if risk to sight
what is periorbital cellulitis?
eyelid and skin infection of orbital septum in front of eye
red, swollen hot skin around eye and eyelid
can progress to orbital cellulitis
should be seen in secondary care
what is the management of periorbital cellulitis in adults?
1 - Co-amoxiclav 500/125mg TDS for 7 days PO
Pen allergy -
Clarithromycin 500mg BD 5-7 days
PLUS Metronidazole 400mg TDS for 7 days
what is the management of periorbital cellulitis in children?
<30 days - r/f ophthalmology
Co-amoxiclav 0.25ml/kg of 125/31 oral suspension
OR
12-17 years - 25-/125mg TDS PO tablets
Clarithromycin in allergy
what is orbital cellulitis?
infection around the eyeball involving tissues behind orbital septum
what are 7 presentations of orbital cellulitis?
Redness and swelling around eye
severe ocular pain
visual disturbance
Proptosis
Pain with eye movements - ophthalmoplegia
Eyelid oedema and ptosis
Symptoms of meningeal involvement
what imaging can be used for orbital cellulitis?
CT with contrast to distinguish orbital and periorbital cellulitis - for all patients suspected
what are the 3 of the most common organisms causing orbital cellulitis?
Streptococcus
Staphylococcus Aureus
Haemophilus influenzae B
what is the management of orbital cellulitis?
Admission for IV Abx - as per local guidelines - Cefotaxime + flucloxacillin
what are the 4 most common causative organisms for preorbital cellulitis?
Staph Aureus
Staph Epidermis
Streptococci
Anaerobes
what age group are most affected be periorbital/orbital cellulitis?
children - <10
what is primary open angle glaucoma?
a chronic progressive optic neuropathy characterised by degeneration of retinal ganglion cells and their axons leading to irreversible visual field loss due to chronic raised intraocular pressure and subsequent stress on the optic nerve head
what is normal intraocular pressure?
10-21mmHg
what are 7 risk factors for chronic open angle glaucoma?
Increased age
FHx
Black ethnic origin
Myopia
HTN
DM
Corticosteriods
what 5 presentations of chronic open angle glaucoma?
Gradual onset of peripheral vision loss - tunnel vision
Fluctuating pain
Headaches
Blurred vision
Halos around lights particularly at night
what are 2 ways to measure intraocular pressure?
non contact tonometry - puff of air
goldmann applanation tonometry - GOLD STANDARD - device mounted on sit lamp that applies various pressures to eye
what 4 things can be seen on fundoscopy in chronic open angle glaucoma?
increased optic cup to disc ratio >0.7
optic disc pallor - due to optic atrophy
bayonetting of vessels
cup notching and disc haemorrhages
what are 5 tools for diagnosis of chronic open angle glaucoma?
Goldmann applanation tonometry - for intraoccular pressure
Slit lap assessment of retinal health
Visual field assessment - peripheral vision loss
Gonioscopy - assess angle between iris and cornea
Central corneal thickness assessment
At what pressure is treatment for chronic open angle glaucoma usually started?
> 24mmHg
what is the 1st line management of chronic open angle glaucoma?
360 degree selective laser trabeculoplasty
laser directed at trabecular meshwork to improve drainage and delay need for eye drops
what is the 1st line medical treatment for chronic open angle glaucoma?
Prostaglandin analogues - latanoprost
increase uveoscleral outflow
what are 3 side effects of prostaglandin analogues?
lash growth
eyelid pigmentation
iris pigmentation - browning
what are 3 alternative medical therapies for chronic open angle glaucoma?
B Blockers - timolol - reduce production of aqueous humour
Carbonic anhydrase inhibitors - dorzolamide - reduce production of aqueous humour
Sympathomimetics - brimonidine - reduce production of aqueous fluid and increase uveoscleral outflow
what is the definitive management of chronic open angle glaucoma if other treatment fails?
Surgical trabeculectomy to create new channel from anterior chamber for humour resorption
what are 3 side effects of miotics (pilocarpine)?
constricted pupil
headache
blurred vision
what is an example of a prostaglandin analogue?
Latanoprost
what is latanoprost used for?
Prostaglandin analogue 1st line in medical management of chronic open angle glaucoma
what is the most common cause of blindness is in the UK?
Age related macular degeneration
what are 4 risk factors for age related macular degeneration?
Advanced Age - 3x risk >75 years
Smoking - 2x more likely
FHx - 4x risk
Risk of ischaemic cardiovascular disease increases risk of ARMD
What are the 2 classifications of age related macular degeneration?
Dry and Wet
what is the macula?
area in the centre of the retina that generates high def colour vision in the central visual field
what are the 4 layers of the macula?
Choroid layer - blood vessels
Brusch membrane
Retinal pigment epithelium
Photoreceptors - at surface
what are drusen?
yellowish deposits of proteins and lipids between retinal pigment epithelium and Bruch membrane in macula. Frequent and large druses can be a sign of macular degeneration
what are 3 retinal signs of macular degeneration?
Drusen
Atrophy of retinal pigment epithelium
Degeneration of photoreceptors
what is the difference between wet and dry macular degeneration?
Macular degeneration is caused by the degeneration of retinal photoreceptors
In wet macular degeneration there is neovascularisation from the choroid layer into the retina causing oedema and faster vision loss
Is wet or dry macular degeneration more common?
Dry - 90%
Wet - 10%
what chemical stimulates neovascularisation in wet macular degeneration?
vascular endothelial growth factor
what is the presentation of macular degeneration?
gradual loss of central vision
reduced visual acuity
crooked or wavy appearance of straight lines - metamophopsia
often present with gradually worsening ability to read small text
Wet AMD can develop within days and progress to complete vision loss in a few years
what are 4 findings on examination for macular degeneration?
reduced visual acuity with snellen chart
scotoma - enlarged central area of vision loss
ambler grid test for straight lines
Drusen on fundoscopy
what are 2 ways of visualising macular degeneration?
Optical coherence tomography - gives cross section of layers of retina
Fluorescein angiography - flurorescein contrast and photographing the retina to assess the blood supply showing oedema and neovascularisation in wet AMD
what medications are used in wet age related macular degeneration and what are their names?
anti-vascular endothelial growth factor medications - injected into vitreous chamber usually once a month
E.g. - Ranibizumab, aflibercept, bevacizumab
what is the management of dry macular degeneration?
monitoring and reducing risk - stop smoking, control BP, vitamin supplements
what are 6 risk factors for cataracts?
Increased age
smoking
Alcohol
Diabetes
Steroids
Hypocalcaemia
what is cataracts?
progressive opacity of the lens of the eye reducing light entering the eye and decreasing visual acuity
what is the role of the lens and how does it work?
Lens focuses light onto the retina
held in place by suspensory ligaments attached to ciliary body which contracts and relaxes to change shape of lens
No blood supply but is nourished by aqueous humour
what are 4 presentations of cataracts?
Asymetical
Slow reduction in visual acuity
Progressive blurring of vision
Colours become more faded, brown or yellow
Stardust’s spear around lights especially at night
what is a key examination finding in cataracts?
Loss of red reflex
what is a rare but serious complication of cataracts surgery?
Endophthalmitis - inflammation of inner contents of eye usually caused by infection - can lead to vision loss
Tx with intravitreal Abx injected directly into eye
what are 6 common causes of loss of red reflex?
Cataracts
Corneal Scars
Vitreous Haemorrhage
Retinoblastoma
Macular degeneration
Diabetic retinopathy
what is the name for a white red reflex?
leukocoria - commonly seen in retinoblastoma, also seen in congenital cataracts
what are 4 ways to investigate loss of red reflex?
Ophalmic USS - can visualised intraocular structures and detect masses, retinal derangement and vitreous haemorrhage
MRI
Serology - for infective causes
Cytology and Histopathology for masses
what are 2 intraoperative complications of cataracts surgery?
Capsular tear - causes vitreous loss or dislocation of lens fragments into vitreous cavity
Zonular dehiscence
what are 4 postoperative complications of cataracts surgery?
Posterior capsule opacification - most frequent - lens epithelial cells proliferate and migrate onto posterior capsule - YAG laser capsulotomy required for treatment
Cystoid macular oedema - fluid accumulation in macula - Tx steroid and NSAIDs
Endophthalamitis
Intraocular lens dislocation - surgery required to correct
where does the central retinal artery branch from?
Internal carotid artery branches to ophthalmic artery which branches to central retinal artery
what are 2 causes of central retinal artery occlusion?
Atherosclerosis - most common
Giant cell arteritis
what are 7 Risk factors for central retinal artery occlusion?
RF for CVD - HTN, Smoking, Diabetes, raised cholesterol
RF for GCA - White, Older age, female, polymyalgia rheumatic
what is relative afferent pupillary defect?
when pupil in affected eye constricts more when light is shone in other eye than when it is shone in affected eye
what is the clinical presentation of central retinal artery occlusion?
Sudden painless loss of vision
what 2 things will be seen on fundoscopy in central retinal artery occlusion?
Pale retina - due to lack of perfusion
Cherry red spot on retina - thinned fovea showing red choroid below
what are 4 differentials for sudden (acute) painless vision loss?
Retinal detachment
Central retinal artery occlusion
Vitreous Haemorrhage
Retinal detachment
Amaurosis fugal describes a temporary loss of vision caused by interruption to blood flow
what are 3 differentials for visual loss over hours to days?
Anterior ischaemic optic neuropathy
Central retinal vein occlusion
Glaucoma - acute angle close
what are 2 differentials for visual loss over days to weeks?
Optic neuritis
Wet macular degeneration
what are 4 differentials for visual loss over months to years?
Glaucoma - open angle
Dry age related macular degeneration
diabetic retinopathy
cataracts
what is the management of central retinal artery occlusion?
GCA Tx if cause - High doe steroids
Ocular massage
Intra-arterial thrombolysis - urokinase administered directly though ophthalmic artery catheterisation
Vasodilatory therapy -I nhaled Carbogen, ublingual isosorbide dinitrate, oral pentoxifylline
Reduction of intraocular pressure - anterior chamber paracentesis, medications
what is the secondary prevention of central retinal artery occlusion?
Carotid source of emboli - carotid enartectomy if stenosis >50%
Cardiac source of emboli - long term anticoagulant
uncertain aetiology - anti platelets and atherosclerosis risk factor modifications
where do the retinal veins drain?
Drain into central retinal vein which runs through optic nerve then into either superior ophthalmic vein or cavernous sinus
what is retinal vein occlusion?
blockage of retinal vein cabin venous congestion in retina and increased pressure leading to blood leakage into retina causing macula oedema and retinal haemorrhages leading to retinal damage and vision loss
what are 7 risk factors for retinal vein occlusion?
HTN
High cholesterol
Diabetes
Smoking
High plasma viscosity
Myeloproliferative disorders
Inflammatory conditions
what is the presentation of retinal vein occlusion?
painless blurred vision or vision loss
what is seen on fundoscopy in retinal vein occlusion? 6
Dilated tortuous retinal veins
Flame/Blot haemorrhages - stormy sunset appearance
Retinal oedema
Cotton wool spots
Hard exudates
what is the management of retinal vein occlusion?
treatment of macular oedema and prevention of neovascularisation using anti-VEGF therapies, Intravitreal dexamethasone and laser photocoagulation of new vessels
what is the sclera?
the outer layer of connective tissue surrounding most of the eye excluding the cornea
What is a complication of scleritis?
can become necrotising scleritis and lead to scleral perforation
what is the presentation of scleritis?
severe painful red eye
congested vessels
Pain with eye movement
photophobia and watering
reduced visual acuity
tender on palpation
what are 3 causes of scleritis?
Autoimmune disease - RA, LSE, Vasculitis
Infection
Trauma
what are 4 complications of scleritis?
Corneal thinning
cataracts
glaucoma
scleral perforation
what is the management of scleritis?
referral to Ophthalmology
NSAIDs
Steroids
Immunosuppresion - if caused by autoimmune condition
Abx
what is episcleritis?
Non-paiful inflammation of the outermost layer of the sclera just below the conjunctiva
Common in young and middle aged adults and associated with inflammatory disorders
what can be used to differentiate between episcleritis and scleritis?
phenylephrine eye drops - causes blanching of episcleral vessels causing redness to disappear in episcleritis
what are the 3 most common organisms to cause infective keratitis?
pseudomonas aeruginosa - creamy white corneal infiltrates
Staph aureus
herpes simplex virus
Fungi and parasites less commonly
what is keratitis?
a severe corneal infection caused by pathogens
what is the presentation of Infective keratitis? 5
painful red eye
photophobia
Reduced visual acuity
Visible corneal infiltrate
eye watering
what are 7 complications of infective keratitis?
corneal scaring
perforation
endophthalmitis
blindness
cataracts formation
secondary glaucoma
scleritis and episcleritis
what are 5 risk factors for infective keratitis?
Contact lens use
ocular surface disease - dry eyes, blepharitis, meibomian gland dysfunction
trauma
previous ocular surgery
Impaired immunity
what can be used to confirm infective keratitis?
corneal scrapings for MCS
what antibiotics are used in infective keratitis?
Fluoroquinolones - ciprofloxacin, levofloxacin, gemifloxacin
what is keratitis?
inflammation of the cornea
what is the most common microbial cause of keratitis?
HSV-1
what causes recurrent Herpes simplex keratitis?
HSV virus becomes latent in trigeminal ganglion and can reactive
what is required to diagnose keratitis?
Slit lamp examination
what is seen on slit lamp exam in Herpes simplex keratitis?
fluorescein staining shows dendritic corneal ulcer - branching ulcer
what is the management of Herpes simplex keratitis?
topical or oral antivirals - aciclovir PO 200mg 5x a day 5 days or Eye ointment 1cm 5x daily until 3 days after healed
or ganciclovir
what is a surgical option to manage keratitis complications?
Corneal transplant for scaring and vision loss
what can be used to visualise corneal abrasions?
Fluorescein eye drops - stains abrasions yellow to naked eye
especially evident under cobalt blue light
what are 3 different types of lubricating eye drops?
Hypromellose - least viscus - 10 minute effect
Polyvinyl alcohol - middle viscus
Carbomer - most viscus - 30-60 minute effect
what are 5 presentations of corneal abrasion?
painful red eye
photophobia
foreign body sensation
epiphora - excessive tearing
blurred vision
what is hyphema?
blood in the anterior chamber of the eye in front of iris
urgent ophthalmology referral
what are 4 features of hyphema?
eye pain/swelling
proptosis
rockhard eyelids
relevant afferent pupillary defect
what is the emergency management of hyphema?
lateral canthotomy - surgery to lateral cantos (corner or eye) incision made to relieve fluid pressure and decrease IOC pressure
what are 4 risk factors for Subconjunctival haemorrhage?
heavy coughing
weight lifting
straining while constipated
trauma to eye
HTN
Bleeding disorders
Whooping cough
Meds - antiplatelets/coagulants
NAI
what is the presentation of a subconjuctival haemorrhage?
bright red blood under conjunctiva covering white of eye - painless and does not affect vision
How long does it take Subconjunctival haemorrhages to resolve?
2 weeks
what is retinal detachment?
neurosensory layer of retina with photoreceptors and nerves separates from retinal pigment epithelium usually due to retinal tear allowing vitreous fluid between the two layers
neurosensory layer relies on supply from choroid so detachment can cause permanent damage
what are 7 risk factors for retinal detachment?
Lattice degeneration
posterior vitreous detachment
trauma
diabetic retinopathy
retinal malignancy
Fhx
Myopia
what are 3 presentations of retinal detachment?
Painless peripheral vision loss, loss of visual fields - described as shadow coming across vision
Blurred or distorted vision
flashers and floaters
what is the management of retinal tears?
layer therapy or cryotherapy
what is the management of retinal detachment?
vitrectomy - keyhole surgery to remove vitreous fluid and fix tear, add gas to hold retina in place
scleral buckle - silicone buckles to put pressure on sclera from outside eye to reconnect layers
pneumatic retinopexy - injecting gas bubbles into vitreous body to press layers back together
what are 3 presentations of conjunctivitis?
red blood shot painless eyes
itchy/gritty sensation
discharge
what is the presentation of bacterial versus viral conjunctivitis?
bacterial more purulent discharge worse in morning
viral discharge usually clear and concurrent with other viral illness, raised pre auricular lymph nodes
what are 7 causes of an acute painful red eye?
Acute angle closure glaucoma
anterior uveitis
scleritis
corneal abrasion/ulceration
keratitis
foreign body
trauma/chemicals
what are 3 causes of an acute painless red eye?
conjunctivitis
episcleritis
Subconjunctival haemorrhage
what can be given manage bacterial conjunctivitis? (same in children and adults)
chloramphenicol 0.5% - 1 drop ever 2 hours reducing for 48 hours after healing
Fuscidic acid eye drops 1% - BD - SAFE IN PREGNANCY
what advice should be given to contact lens wearers with conjuctivitis?
Stop wearing lenses
bathe eyelids with cooled boiled water on cotton wool
Avoid contact lenses till symptoms have cleared
What are 7 red flags in a red eye Hx requiring immediate referral to ophthalmology?
Reduced visual acuity
Marked eye pain, headache or photophobia
Neonate (<30 days)
Hx of trauma/possible foreign body
Copius rapidly progressive discharge - ?gonorrhoea
Herpes virus infection
Soft contact lens use with corneal symptoms - watering, photophobia
what are 4 common bacterial causes of conjunctivitis?
S aureus
Strep pneumoniae
Haemophilus influenzae
Mortadella catarrali
what is the most common viral cause of conjunctivitis?
adenovirus
who should be referred to ophthalmology immediately with conjunctivitis?
Neonates - ophthalmia neonatorium
Can be due to chlamydia/gonorrhoea infection
what is anterior uveitis?
inflammation of the anterior uvea which includes iris, ciliary body and choroid
what are 5 causes of anterior uveitis?
autoimmune - most common
Infection
trauma
ischaemia
malignancy
what are 4 autoimmune conditions associated with anterior uveitis?
seronegative spondyloarthropathies - HLA-B27
IBD
Sarcoidosis
behcet’s disease
what are 4 symptoms of anterior uveitis?
Painful red eye - dull achy
Photophobia
Reduced visual acuity
excessive lacrimation
what are 4 findings in anterior uveitis?
Ciliary flush - red ring from cornea outwards
Miosis
Abnormally shaped pupil due to adhesions
Hypopyon - collection of inflammatory cells as white fluid in anterior chamber
what is the management of anterior uveitis?
1 - corticosteroids
AND Cycloplegics - Cyclopentolate or atropine 1% eye drops - to dilate pupil and reduce Hilary spasm pain
recurrence may require DMARDS or anti TNF meds
what are 5 complications of anterior uveitis?
posterior synechiae - adhesions between iris and lens leading to pupil distortion and angle closure glaucoma
Cataracts
glaucoma
Cystoid macular oedema
Band keratopathy
what is the presentation of optic neuritis? 6
sudden onset vision loss
painful eye movements
changes in colour perceptions - dyschromatopsia
Relative afferent pupillary defect
visual field defects
impaired light adaption
what are 2 risk factors for thyroid eye disease?
smoking
radioiodine treatment
what is the pathophysiology of thyroid eye disease?
Autoimmune response against auto antigen on THS receptor expressed on bothy thyroid follicular cells and orbital fibroblasts
Increased production of cytokines and chemokine promoting inflammatory cell infiltration
Inflammation results in glycosaminoglcan and collagen deposit in extra ocular muscles and connective tissues
what are 5 presentations of thyroid eye disease?
Exophthalmos (proptosis) - eyes bulging out
conjunctival oedema
Optic disc swelling
Ophthalmoplegia - paralysis of eye muscles
may have any thyroid level - eu, hypo, hyper
what is the management of thyroid eye disease?
topical lubricants
Corticosteroids
radiotherapy
surgery - orbital decompression if there is optic nerve compression due to oedema
what are 6 red flags for referral to ophthalmology in thyroid eye disease?
Unexplained deterioration in vision
Change in colour vision
eye ‘popping out’ - globe sublaxation
obvious corneal opacity
cornea visible with eyes closed
disc swelling
what are 3 complications of thyroid eye disease?
Exposure keratopathy - most common due to corneal exposure
Optic neuropathy
Strabismus and diplopia - due to fibrosis of extraoccular muscles
what is the usual presentation of a corneal foreign body?
pain, tearing, redness, photophobia, foreign body sensation
when should corneal foreign body presentations be referred to ophthalmology?
Suspected penetrating eye injury/high velocity mechanism
significant oribital/periorbital trauma
Foreign body near centre of cornea
Foreign body composed of organic material - higher infection risk
chemical injury
what is the management of corneal foreign body?
Topical anaesthesia - proparacaine hydrochlorine 0.5% or tetracaine hydrochloride 1%
Irrigation
Needle technique
Jeweller’s forceps
Buratto technique
Abx prophylaxis - chloramphenicol 0.5% or ofloxacin 0.3%
Cycloplegia (cyclopentolate hydrochloride 1%) for cilliary spasm
Analgesia
Tetanus prophylaxis
what is concomitant strabismus?
Due to imbalance in extra ocular muscle strength
convergent more common than divergent
what is paralytic strabismus?
due to paralysis of extra ocular muscle(s)
why are eye patches used in squint?
to prevent amblyopia - where brain favours use of one eye and fails to process input from other eye
what is esotopia?
inward positioned squint
what is exotropia?
outward positioned squint
what is hypertropia?
upwards moving affected eye in squint
what is hypotonia?
downward moving affected eye in squint
what are 5 causes of squint?
Idiopathic
Hydrocephalus
Cerebral palsy
space occupying lesion
trauma
what tests can be used to identify squint?
Hirschberg’s test - shine pen torch 1m away from patient, observe reflection of light - should be central and symmetrical, deviation indicates squint
cover test to identify type of squint
until what age are the visual fields developing?
8 years
what is the management of squint?
occlusive patch to cover good eye
atropine drops in good eye to blur vision
What is posterior vitreous detachment?
when the vitreous body comes away from retina
Common in older age
what are 3 presentations of posterior vitreous detachment?
Floaters
Flashing lights
Blurred vision
Can be completely asymptomatic
what is the management of posterior vitreous detachment?
No treatment necessary - symptoms improve over time as brain adjusts
Predisposes patients to retinal tears and retinal detachment - can present with similar flashers and floaters
what are floaters?
small, dark shadowy shapes that drift into field of vision
Usually caused by age related changes to vitreous humour
what are flashes?
brief sensation of light that can occur when the retina receives a non-light induced simulation
Associated with posterior vitreous detachment, retinal breaks and retinal detachment
rarely - optic neuritis, ocular migraines occipital lobe infarct
what is monocular diplopia?
persists even when one eye is closed
often due to refractive errors, corneal abnormalities, lens dislocation or cataracts
what is binocular diplopia?
disappears when one eye is closed
usually due to strabismus, CN palsies, thyroid eye disease, Myasthenia graves or orbital lesions
what are 3 differentials for monocular diplopia?
Keratoconus - corneal disorder
Cataracts - opacities scatter light leading to double vision
Retrobulbar lesions - optic neuritis
What are 3 causes of binocular diplopia?
CN palsies - CNIII, IV, VI
Neuromuscular junction disorders - Myasthenia graves, Lambert eaton syndrome
Extraocular muscle disorders - Thyroid eye disease, orbital myositis
what is the pathophysiology of diabetic retinopathy?
Hyperglycaemia damages retinal small vessels and endothelial cells
increased vascular permeability leads to leaking blood vessels, blot haemorrhages and hard exudates in the retina
damage to blood vessel wall leads to micro aneurysms and venous beading
Damage to nerve fibres in the retina cause fluffy white cotton wool spots in retina
intraretinal microvascular abnormalities - dilated tortuous capillaries in retina - shunt between arterial and venous vessels
Neovascularisation due to vascular endothelial growth factor stimulating new blood vessels
what is the grading of diabetic retinopathy?
Background - micro aneurysms, retinal haemorrhages, hard exudates and cotton wool spots
Pre-proliferative - venous beading, multiple blot haemorrhages, intraretinal microvascular abnormalities
Proliferative - neovascularisation and vitreous haemorrhage
what are 7 complications of diabetic retinopathy?
vision loss
retinal detachment
vitreous haemorrhage
rubeosis iris
glaucoma
optic neuropathy
cataracts
what is the management of non-proliferative diabetic retinopathy?
close monitoring and good diabetic control
what is diabetic maculopathy?
macular oedema caused by leakage from damaged capillaries
what are 7 risk factors for diabetic eye disease?
poor glycemic control
longer duration of diabetes
hypertension
dyslipidaemia
nephropathy
smoking
poor diet and obesity
what are 5 presenting features of diabetic eye disease?
Asymptomatic
Vision changes - blurred, fluctuating
Floaters - due to vitreous haemorrhage from new vessel formation
Sudden visual loss - vitreous haemorrhage
Gradual vision loss
what examination findings are seen in diabetic eye disease?
fundus
- micro aneurysm
dot and blot haemorrhages
hard exudates
cotton wool spots
venous beading
intraretinal microvascular abnormalities
Macular oedema
new vessel formation
what 5 investigations are used assessing diabetic eye disease?
Fundus photography
Fluorescein Angiography
Optical coherence tomography
Tonometry - DM increases risk of glaucoma
Hba1c and lipids
How often should people with diabetes get their eyes tested?
every year after the age of 12 or 5 years since diagnosis for T1DM
Every year from diagnosis in T2DM
what is the management of proliferative diabetic eye disease?
Pan-retina photocoagulation - laser treatment to suppress new vessels
Anti-VEGF intravitreal medications
Vitreoretinal surgery
what blood pressure treatment is used in diabetes?
ACEi
what is the name of the anti-VEGF medication licensed for diabetic retinopathy?
ranibizumab
what is a signs of allergic conjunctivitis?
bilateral, itchy , sore swollen eyelids
Sign - papillae under lids
what is the management of allergic conjunctivitis?
antihistamine drops
mass stell stabilisers
topical steroids
what nucleus does the optic tract terminate in and where in the brain is it?
Lateral geniculate nucleus
thalamus
where is the defect in an ipsilateral monocular blindness?
lesion of that sided optic tract pre-optic chiasm
what are 5 causes of monocular blindness?
Optic neuritis
amaurosis fugax
optic atrophy
retrobulbar optic neuropathy
Trauma
where is the defect in a bilateral temporal hemianopia?
optic chiasm
what are 2 causes of bilateral hemianopia?
pituitary adenoma
suprasellar aneurysm
where is the defect in an superior (upper) homonymous quadrantanopia?
Superior defects = Temporal (myers) optic radiation defects
where is the defect in an inferior (lower) homonymous quadrantanopia?
inferior = Parietal lobe optic radiation defects
How do you remember what optic radiation supplied superior or inferior visual fields?
PITS
Parietal
Inferior
Temporal
Superior
what is the most common cause of homonymous quadrantinopias?
occipital lobe lesions
what is a key feature of optic lobe lesion visual field defects?
MACULAR SPARING
what does hypertensive retinopathy look like on fundoscopy?
Papilledema
Macular star
retinal haemorrhages
cotton wool spots
