Ophthalmology Flashcards
causes of optic neuritis?
- MS (most common)
- DM
- syphilis
features of optic neuritis?
- unilateral reduction in visual acuity
- relative afferent pupillary defect
- loss of colour discrimination
- “red desaturation”
- central scotoma
management of optic neuritis? how long does it take to fully recover?
- high-dose steroids
- 4-6 weeks
prognosis of optic neuritis?
if >3 white matter lesions seen on MRI, very high risk of developing MS
describe the pathophysiology of (all types of) glaucoma
- blockage in aqueous humour drainage from eye
- causes rise in intraocular pressure
- this raised pressure damages the optic nerve (CN2)
which fluid fills the anterior chamber? vitreous chamber?
- aqueous humour
- vitreous humour
which structure produces aqueous humour?
ciliary body
what is normal intraocular pressure?
10-21 mmHg
pathophysiology of open-angle glaucoma?
- gradual increase in resistance through trabecular meshwork
- pressure slowly builds in eye
pathophysiology in acute angle-closure glaucoma?
- iris bulges forward
- completely seals off trabecular meshwork
- continual build up of pressure
- emergency
how does increased intraocular pressure affect the optic disc?
- causes “cupping”
- optic cup in centre of disc gets wider and deeper
risk factors for open angle glaucoma?
- ageing
- FHx
- Black ethnic origin
- myopia (short-sightedness)
presentation of open angle glaucoma?
- often asymptomatic, picked up on screening
- loss of peripheral vision first
- eventually gives “tunnel vision”
- gradual onset
- fluctuating pain
- headaches
- blurred vision
- halos around light, esp at night
how can intraocular pressure be measured in suspected glaucoma?
- non-contact tonometry (puff of air, useful for screening)
- goldmann applanation tonometry (gold standard)
investigations and findings in open angle glaucoma?
- goldmann applanation tonometry (high intraocular pressure)
- fundoscopy (disc cupping)
- visual field assessment (peripheral vision loss)
at what intraocular pressure should treatment be started in open angle glaucoma?
24mmHg or above
management of open angle glaucoma?
- 1st: latanoprost (prostaglandin analogue) eye drops
- timelol (BB)
- dorzolamide (carbonic anhydrase inhibitor)
- brimonidine (sympathomimetic)
- trabeculectomy surgery if eye drops fail
notable SEs of latanoprost?
- eyelash growth
- eyelid pigmentation
- iris browning
risk factors for acute angle closure glaucoma?
- ageing
- being female
- FHx
- Chinese / East Asian ethnic origin
- drugs
which drugs can precipitate acute angle closure glaucoma?
- noradrenaline
- oxybutynin / solifenacin
- amitriptyline
presentation of acute angle closure glaucoma?
- pt feels generally unwell
- severely painful, red eye
- blurred vision
- halos around lights
- headache
- N+V
findings O/E of acute angle closure glaucoma?
- red-eye
- teary eye
- hazy cornea
- decreased visual acuity
- affected pupil is dilated and fixed in size
- eyeball is firm on palpation
initial management of acute angle closure glaucoma?
- same day ophthalmology assessment
- lay on back w/ pillow
- pilocarpine eye drops
- PO acetazolamide 500mg
- analgesia / antiemetics if needed
drug class of acetazolamide?
carbonic anhydrase inhibitor
secondary care management of acute angle closure glaucoma? hint: similar to open angle
- pilocarpine
- PO / IV acetazolamide
- glycerol / mannitol
- timolol
- dorzolamide
- brimonidine
- laser iridotomy
definitive treatment of acute angle closure glaucoma?
laser iridotomy
most common cause of blindness in the UK?
age-related macular degeneration (ARMD)
key finding on fundoscopy in ARMD?
drusen
how can ARMD be classified? which type is most common?
- dry (90%)
- wet (10%)
which type of ARMD carries a worse prognosis?
wet
feature common to both dry and wet ARMD?
drusen on fundoscopy
risk factors for ARMD?
- ageing
- smoking
- White / Chinese ethnic origin
- FHx
- CVD
presentation of ARMD?
- gradually worsening central visual field loss
- reduced visual acuity
- straight lines look crooked / wavy
how might wet ARMD present slightly differently to dry ARMD?
- more acute
- vision is lost over days
- full blindness after 2-3 years
findings O/E of ARMD?
- reduced acuity
- scotoma on visual fields test
- distorted straight lines on amsler grid test
- drusen on fundoscopy
what is a scotoma?
a central patch of vision loss
specialist investigations used in ARMD?
- slit-lamp biomicroscopic fundus exam
- optical coherence tomography
- fluoroscein angiography
management of dry ARMD?
- refer to ophthalmology
- stop smoking
- control BP
- vitamin supplements
management of wet ARMD?
- refer to ophthalmology
- anti-VEGFs (ranibizumab, bevacizumab, pegaptanib)
describe the pathophysiology and examination findings in diabetic retinopathy
- repeated exposure to hyperglycaemia causes increased vascular permeability of retina, causing:
- blot haemorrhages
- hard exudates
- microaneurysms
- venous beading
- “cotton wool spots”
- neovascularisation
how can diabetic retinopathy be classified?
based on fundoscopy findings:
- proliferative
- non-proliferative
signs on fundoscopy in mild / moderate non-proliferative diabetic neuropathy?
- mild: microaneurysms
- moderate: microaneurysms, blot haemorrhages, hard exudates, cotton wool spots and venous beading
signs on fundoscopy in severe non-proliferative diabetic retinopathy?
- blot haemorrhages
- microaneurysms in 4 quadrants
- venous beading in 2 quadrants
- IRMA in any quadrant (intraretinal microvascular abnormality)
signs on fundoscopy in proliferative diabetic retinopathy?
- neovascularisation
- vitreous haemorrhage
signs on fundoscopy in diabetic maculopathy?
- macular oedema
- ischaemic maculopathy
complications of diabetic retinopathy?
- retinal detachment
- vitreous haemorrhage
- rebeosis iridis (new blood vessels in iris)
- optic neuropathy
- cataracts
management of diabetic retinopathy?
- laser photocoagulation
- anti-VEGF (ranibizumab, bevacizumab)
- vitreoretinal surgery (keyhole in eye)
how could hypertensive retinopathy develop?
2 ways:
- very slowly from chronic HTN
- quickly in malignant HTN
signs on retina on fundoscopy in hypertensive retinopathy?
- silver / copper wiring (arterioles compressing veins)
- AV nicking
- cotton wool spots
- hard exudates
- retinal haemorrhages
- papilloedema (end stage sign)
how can hypertensive retinopathy be classified?
keith-wagener classification
management of hypertensive retinopathy?
- control BP
- stop smoking
- control lipids
what is a cataract?
- when the lens becomes cloudy and opaque
- causes loss of visual acuity
how are congenital cataracts picked up?
screened for using red reflex in NIPE
risk factors for cataracts?
- ageing
- smoking
- alcohol
- DM
- steroids
- hypocalcaemia
presentation of cataracts?
- asymmetrical
- very slow vision loss
- progressive blurring
- change of colour vision (more yellow / brown)
- “starbursts” in light, esp at night
finding O/E of cataracts?
- loss of red reflex
- might be picked up in flash pics
management of cataracts?
- if asymptomatic, nothing
- surgically breaking less and replacing with artificial lens
why might someone get cataract surgery and still have poor visual acuity afterwards?
cataracts can mask other eye conditions (e.g. macular degeneration, DM retinopathy)
important complication of cataract surgery?
endophthalmitis, secondary to infection
management of endophthalmitis?
intravitreal ABx
causes of abnormal pupil shape?
- trauma from cataract surgery
- anterior uveitis
- acute angle closure glaucoma
- rubeosis iridis
- coloboma
- tadpole pupil
what is the difference between rubeosis iridis and coloboma?
- RI is caused by neovascularisation secondary to DM (retinopathy)
- coloboma is congenital
key associated condition of tadpole pupil?
migraines
causes of mydriasis (dilated pupil)?
- CN3 palsy
- holmes-adie syndrome
- RICP
- congenital
- trauma
- stimulants (e.g. cocaine)
- anticholinergics
causes of miosis (constricted pupil)?
- horner syndrome
- cluster headaches
- argyll-robertson pupil (neurosyph)
- opiates
- nicotine
- pilocarpine
how does CN3 palsy affect the eye?
- ptosis
- dilated, non-reactive (mydriasis) pupil
- divergent squint
- “down and out” position
which unique feature is found in congenital horner syndrome?
heterochromia (different coloured irises)
how can you test for horner syndrome?
- cocaine eye drops
- normal eye will dilate but not in horner syndrome
- alt: adrenalin eye drops (opposite results)
describe the holmes-adie pupil
- unilateral dilated pupil
- slow light responses
- pupil gets smaller over time
features of holmes-adie syndrome?
- HA pupil
- absent ankle reflexes
- absent knee reflexes
describe the argyll-robertson pupil
- “prostitute’s pupil”
- constricted
- accommodates when focussing on object
- does not react to light
what is blepharitis? what does it predispose to?
- inflammation of eyelid margins
- styes
- chalazions
management of blepharitis?
- hot compresses
- gentle cleaning with cotton wool
- hypromellose drops
- polyvinyl alcohol drops
- carbomer drops
what is a stye?
infection of the sebaceous / sweat glands at base of eyelashes
management of a stye?
- hot compress
- analgesia
- topical chloramphenicol if conjunctivitis present / persistent
what is a chalazion? how does it present?
- blocked meibomian gland
- non-tender swelling
management of chalazion?
- hot compress
- analgesia
- consider chloramphenicol
- surgery (last line)
what is an entropion? does it hurt?
- eyelid turns in on itself and eyelashes touch the eyeball
- painful
complications arising from entropion?
- corneal damage
- ulceration
management of entropion?
- taping eyelid down to prevent it turning in on itself
- lubricating eye drops (to stop dryness)
- same-day referral if risk to sight
what is an ectropion?
- eyelid turning outwards, exposing inner eyelid mucosa
- usually bottom lid affected
complication of ectropion?
exposure keratopathy, due to dryness
management of ectropion?
- mild cases may need nothing
- regular lubricating eye drops
- same-day referral if risk to sight
what is trichiasis?
- inward growth of eyelashes
- causes pain
complications of trichiasis?
- corneal damage
- ulceration
management of trichiasis?
- specialist epilation of lashes
- electrolysis if recurrent cases
- crytherapy
- laser treatment
- same-day referral if risk to sight
what is periorbital cellulitis?
infection of eyelid and skin in front of eye
presentation of periorbital cellulitis?
- swelling around eye
- redness
- skin hot to touch
key differential of periorbital cellulitis? how can these be distinguished?
- orbital cellulitis
- CT
management of periorbital cellulitis?
- PO / IV systemic ABx
- admit and observe if severe
what is orbital cellulitis?
infection around eyeball involving tissue behind orbital septum
features of orbital cellulitis NOT found in peri-orbital cellulitis?
- pain on movement
- reduced eye movement
- changes in vision
- abnormal pupil reactions
- proptosis
management of orbital cellulitis?
- emergency!
- admit
- IV ABx
- surgical drainage if abscess present