Ophthalmology Flashcards
what is the function of the trabecular mesh ? another name for this ?
canal of schlemm
- drains aqueous humour, helps reduce pressure of eye
what does the lens separate in the eye ?
separates anterior + posterior compartments of the eye
what is found in anterior chamber ? what in posterior ?
- anterior: aqueous humour
- posterior: vitreous humour
what is the cornea - function ?
outer most layer of the eye
- helps with light refraction
what produces the aqueous humour ?
ciliary body
what forms the uvea ? (3)
- iris
- ciliary body
- choroid
which structures involved in anterior uveitis ?
iris and ciliary body
what is a normal intraocuular pressure ?
10 - 21 mmHg
name some causes of acute painful red eye ? (6)
- acute angle closure glaucoma
- anterior uveitis
- scleritis
- corneal abrasion
- keratitis
- foreign body
name some causes of acute painless red eye ? (3)
- conjunctivitis
- episcleritis
- sub-conjunctival haemorrhage
what is keratitis ?
inflammation of the cornea
keratitis aetiology ? most common ?
viral (more common): HSV
bacterial (more common in lens wearers)
viral keratitis px ?
- red, painful eye
- photophobia
- tears
(can present as recurrent infections )
dendrites shape ulcer seen on fluorescent dye test. what is causing it ?
HSV keratitis
viral keratitis mx ?
- urgen opthal r/v
- topical aciclovier
- coreanal transplant (if permanent scarring and vision loss after keratitis)
bacterial keratitis mx ?
topical Obx (ofloxacin)
(common in lens wearers)
bacterial conjunctivitis px ? what features does it not have ?
acute onset: red eye (can be painful, but not usually)
- eyes sticking
- yellowy mucus
(no photophobia or reduced visual acuity)
bacterial conjuncitivial common pathogen ? mx ?
commonly s.aureus
- tx: topical chloramphenicol
- good hygiene
neonatal conjunctivitis mx ?
urgen opthal r/v (as can be gonococcal infection)
allergic conjunctivitis mx ?
antihistamines (oral of topical)
what can cause scleritis ? (3)
- idiopathic (no clear cause)
- underlying systemic inflammation condition
- infection (s.aureus)
RA has associated with what condition ?
sero negative spondyloarthropathies have association with what condition ?
- RA/vasulitits (GPA): scleritis
- seronegative spondyloarthropathies): anterior uveitis
whith which other conditions is scleritis often associated with ? (2)
- RA
- vasculitis (often GPA)
scleritis ps x ? (5)
more gradual onset, uni or bilateral
- very painful (wake up at night) red eye
- pain with eye movement
- photophobia
- associated with vision loss
- excessive tear production
scleritis mx ?
- urgent opthal r/v
- steroids
- consider immunosuprresions if due to underlying systemic condition
how to distinguish between epi vs scleritis ? (2)
- scleritis has pain
- scleral vessels don’t blanch with phenylephrine drops whereas epi vessels do
what is open angle glaucoma ? pathophys
optic nerve damage caused by raised intraocular pressure
- caused by blockage to aqueous humour trying to escape eye due to gradual increase in resistance through trabecular meshwork
how does open angle glaucoma affect optic disc ?
leads to cupping of optic disc
=> optic cup > 0.5 size of optic disc
open angle glaucoma RF ? (3)
- increasing age
- FHx
- near sightedness
open angle glaucoma px ? (5)
often asx for a long time
- affects peripheral vision first: progressive constraint visual field over months => tunnel vision
- visual acuity remains good
- headaches
- halos around lights
- fluctuating pain
(peripheral vision loss + halos)
open angle glaucoma ix ? what would they show ?
- non contact tonomtery (raised pressure
- funcdoscopy (cupping of optic disc)
open angle glaucoma mx ? what definitive procedure ?
aim to reduce intraocular pressure
- prostaglandin analgye (first line): latanoprost eye drop
- BB: topic timolol
- surgery: (when eye drops ineffective): trabeculectomy
eye prostaglandin analogue SE ?
- luscious eye lashes
- eyelash pigmentation
- iris pigmentation
what is acute angle closure glaucoma ? pathosphsy
ophthalmology emergency
optic nerve damage caused by increased intraoccqular pressure caused by blockage of aqueous humour form the eye
- iris bulges forward (closed angle) => blacks trabecular meshwork
-
acute angle glaucoma complciaiton
opthalmology emergency
- can cause permanent loss of vision
acute angle glaucoma px ?
ps appears unwell
- severely painful red eye
- blurred vision
- hallos
- headache
- headache
- N+V
(peripheral vision loss + halos)
acute angle glaucoma O/E ? (3)
- red teary eye
- reduced visual acuity
- mid dilated non-active pupil
acute angle glaucoma mx ? immediate ? definitive ?
acetazolamide and ambulance
- once in secondary care: laser iridotomy (hole in iris)
What is age related macular degeneration ?
progressive condition affecting macula of the eye
- most common cause of blindness in UK (often unilateral, can be bilateral)
what are the types of age related macular degeneration ?
wet (10%)
dry (90%) Drusen !
age related macular degeneration RF ? (4)
- age
- smoking
- FHx
- obesity
age related macular degeneration px ?
- unilateral gradual vision loss (central scotoma)
- poor visual acuity
- things appearing small + wavy (metamorphopsia)
age related macular degeneration O/E ? (4)
- reduced visual acuity
- central scotoma
- amsler grid test (distortion of straight lines)
- drusens (seen on fundosocpy)
age related macular degeneration Mx ? for the 2 types ?
- dry: not much you can do
- wet: anti VEGF (ranibizumab) injected into eye once a month (intravitreal injection)
describe general px of:
- glaucoma
- AMD
- cataracts
- glaucoma: peripheral vision loss + halos
- AMD: central vision loss + wavy appearance to straight lines
- cataracts: generalised reduction in visual acuity + starburst around light
What is central retinal artery occlusion ?
occurs due to obstruction to blood flow through central retinal artery
causes of central retinal artery occlusion ? (2)
- atherosclerosis
- GCA
central retinal artery occlusion RF ? (4)
(CVD RF)
- smoking
- HTN
- DM
- high cholesterol
central retinal artery occlusion px ?
sudden painless loss of vision (like curtain over vision)
central retinal artery occlusion O/E ? fundoscopy ?
- relative afferent pupillary defect (absent direct but normal consensual reflex)
- fundoscopy: pale retina with a cherry red spot (due to lack of blood perfusion)
central retinal artery occlusion mx ? (3)
emergency (attempt to dislodge or dissolve occlusion)
- if GCA suspected: high dose steroids
- topical timolol (reduce intraoccqular pressure)
- secondary prevention of CVD
causes of sudden painless vision loss ? (4)
- central retinal artery occlusion
- retinal detachment
- central retinal vein occlusion
- vitreous haemorrhage
what is amaurosis fugax ?
temporary loss of vision due to temporary interruption to blood supply
What is retinal vein occlusion ?
thrombus forms in retinal vein => blocks drainage of blood from retina
- can be central retinal vein or branched retinal veins
retinal vein occlusion px ?
painless blurred vision/vision loss
retinal vein occlusion O/E ? (4)
- tortuous dilated retinal veins (pizza pie)
- flame + blot haemorrhages
- retinal oedema
- cotton wool spots
retinal vein occlusion mx ?
immediate opthal r/v
- anti VEGF
what is posterior vitreous detachment ?
when vitreous body comes away form the retina
- common in older age (becomes less firm with age)
posterior vitreous detachment px ? (4)
- can be asx
- painless
- floaters
- blurred vision
posterior vitreous detachment mx ?
no tx needed
posterior vitreous detachment complication ?
can increase risk of retinal tears + detachment
what is retinal detachment ?
retina separates from retinal pigment epithelium (usually due to retinal tears)
- sight threatening condition
retinal detachment px ?
painless
- peripheral vision loss
- blurred distorted vision
- flashing/floaters
retinal detachment mx ?
vitrectomy
What are cataracts ?
when lens of the eye becomes progressively opaque => reduced visual acuity
cataracts RF ? (5)
- old age
- smoking
- alcohol
- DM
- steroids
cataracts px ?
- asymmetrical slow reduction in acuity
- faded colours
- starburst around light
cataracts O/E ? (2)
- loss of red refelx
- lens appears grey/white with ophthalmoscope
catatracts mx ?
cataract surgery
what is hypertensive retinopathy ?
damage to small blood vessels in retina relating to HTN (slowly due to chronic HTN, or quickly due to malignant HTN)
hypertensive retinopathy features ? (4)
- cotton wool spots (due to ischaemia + infarction)
- retinal haemorrhages
- flame haemorrhages
- papiloedema
what is blepharitis ? can lead to what ?
inflammation of eyelid margins (can lead to styes
blepharitis px ?
- gritty
- itchy
- dry sensation to eyes
blepharitis mx ?
- warm compress
- cleaning eyelid margin to remove debris
what are styes ?
tender red lump along eyelid that may contain pus
syte mx ?
- warm compress + analgesia
- if sx persist or sx of conjunctivitis: topical abx (chloramphenicol)
what is entropion ?
when eyelid turns inwards + lashes presses against eye
entropion px ? (2)
- pain
- corneal damage
entropion mx ?
taping eyelid down
what is periorbital cellulitis ? where exactly ? needs to be differentiated form what ?
eyelid + skin inferno in form of orbital septum
- needs to be differentiated form orbital (sigh + life threatening)
what can distinguish peri from orbital cellulitis ?
CT scan
periorbital cellulitis px ?
swollen, red, hot skin
periorbital cellulitis mx ?
systemic abx
- can develop to orbital cellulite so consider admission for monitoring
orbital cellulitis px ?
- pain with eye movement
- visual changes
- abnormal pupil reactions
- proptosis
orbital cellulitis mx ?
- emergency admission
- IV Abx
- consider surgical drainage if abscess forms
What is diabetic retinopathy ? pathophys
it is damage to retinal blood vessels due to prolonged high blood super levels
- hyperglycaemia damages retinal small vessels => leaky blood vessels => blot haemorrhages + hard exudates (yellow deposits on retina)
what are the types of diabetic retinopathy ?
- proliferative (new blood vessel dev - neovascularisation)
- non-proliferative
diabetic retinopathy mx ?
- anti VEGF
- PRP (pan-retinal photocongenlation)
diabetic retinopathy complications ?
- blindness
- retinal detachment
- vitreous haemorrhage
what is anterior uveitis ?
it is inflammation of anterior part of urea (iris and ciliary body)
what causes anterior uveitis ? (3)
- usually caused by autoimmune process
- though can be infection
- or trauma
anterior uveitis px ? (3)
- painful red eye
- reduced visual acuity
- photophobia
anterior uveitis O/E ? (3)
- ciliary flush (redness coming out from in)
- miosis + abnormally shaped pupil
- hypopyon (inflammation cells collected as white fluid in anterior chamber)
anterior uveitis mx ?
- urgent opthal r/v
- steroids: topical, oral, IV
- atropine eye drops
optic neuritis px ? key features ? (4)
unilateral reduced vision
- central scotoma
- pain with eye movement
- impaired colour vision
- relative afferent pupillary defect
