Ophthalmololology Flashcards
What is glaucoma?
optic neuropathy, usually due to raised intra-ocular pressure
what is acute angle closure glaucoma
optic nerve damage secondary to rise in intra-ocular pressure due to impairment in aqueous fluid outflow
iris bulges forward and seals off trabecular meshwork
what are the RFs for AACG
hypermetropia
lens growth with age
pupillary dilatation
shallow anterior chamber, chinese ethnicity
what symptoms of AACG
- painful red eye
- headache
- blurry vision
- worse on mydriasis (pupil dilation) (TV in dark)
- dull cornea (corneal oedema)
- hard, red eye
- haloes around lights
- fixed semi-dilated pupil
- systemic upset - nausea, vomiting, abdo pain
what initial treatment of AACG
- lie patient on back without pillow
- pilocarpine eye drops
- acetozolamide
- timolol
- analgesia and anti-emetic
what secondary care treatment of AACG
- pilocarpine
- acetozolamide
- hyperosmotic agents (mannitol/glycerol)
- timolol
- dorzolamide
- brimonidine
what surgical treatment for AACG
bilateral laser iridotomy
how does pilocarpine work
miotic agent
works on muscarinic receptors in iris sphincter, causes constriction of pupil
also causes ciliary muscle contraction
both actions cause pathway to open up for fluid to leave through trabecular meshwork
how does acetozolamide work
carbonic anhydrase inhibitor
- reduces aqueous fluid production
how does timolol work
beta blocker reduces aqueous fluid production
how does brimonidine work
sympathomimetic, reduces aqueous fluid production
what investigation for AACG
gonioscopy and tonometry
what complications of AACG
sight loss
central retinal artery/vein occlusion
what is blepharitis associated with
rosacea
seborrheic dermatitis
what eye drops in blepharitis
hypromellose
polyvinyl alcohol
carbomer
what symptoms of blepharitits
bilateral grittiness discomfort eyelid margins red swollen eyelid sticky eye in morning styes and chalazions secondary conjunctivitis
what are cataracts
cloudiness and opacification of lens
reduced light entering through lens
what are the symptoms of cataracts
gradual onset: reduced vision faded colour vision glare - lights appear brighter than usual haloes around lights
what key sign of cataracts
loss of red reflex
what investigations for cataracts
ophthalmoscopy - normal fundus and optic nerve
slit lamp - cataracts visible
what RFs for cataracts
age smoking alcohol trauma diabetes long term steroids radiation exposure myotonic dystrophy hypocalcaemia
what mgmt of cataracts
conservative if mild symptoms
cataract replacement surgery
what complications following cataract surgery
endopthalmitis
retinal detachment
posterior capsule rupture
posterior capsule opacification
how is endopthalmitis treated
intravitreal antibiotics
what happens if endopthalmitis is untreated
loss of vision/loss of eye itself
which classification of cataract is most associated with steroid use
subcapsular
what are the two main causes of central retinal artery occlusion
thrombosis secondary to atherosclerosis
giant cell arteritis
what are the RFs for central retinal artery occlusion
same RFs as atherosclerosis (smoking hyperlipidaemia HTN obesity diabetes age FH gender etc.)
GCA/PMR
how does central retinal artery occlusion present
sudden painless loss of vision
what investigations for central retinal artery occlusion and what findings
fundoscopy - pale retina and cherry red spot (macula)
ESR raised
temporal artery biopsy if GCA suspected
what management for central retinal artery occlusion
GCA - prednisolone 60mg thrombosis - ocular massage - removal of fluid from anterior chamber to decrease IOP - carbogen (dilates artery) - isosorbide dinitrate (dilate artery)
what long term management of central retinal artery occlusion
treat RFs
secondary prevention of cardiovascular disease
what is conjunctivitis and how does it present
inflammation of conjunctiva
presents with:
sore gritty red eyes with sticky discharge
NOT PAINFUL
no photophobia/visual loss
what are the two main causes of infectious conjunctivitis and how do they present
bacterial - sticky purulent discharge
viral - serous discharge, preauricular lymphadenopathy, associated with recent URTI
how is bacterial conjunctivitis treated
usually resolves within 2 weeks
advise on good hygiene to avoid spreading
- no sharing towels
- no contact lens
- no school exclusion
- clean eyes with cooled boiled water and cotton wool
topical chloramphenicol eyedrops (fucidic acid if preg)
how is neonatal conjunctivitis treated
if under 1m, urgent ophthalmology review
associated with gonococcal infection
can cause loss of sight/pneumonia
how is allergic conjunctivitis treated
topical antihistamines or mast cell stabilisers (sodium cromoglicate)
avoid contact with allergens
how does allergic conjunctivitis present and how is it treated
bilateral symptoms itchy red eyes swelling of conjunctival sac and eyelid history of atopy may be seasonal/perennial (dust mite etc.)
treatment:
avoid contact with allergens
1st line: topical/oral antihistamines
2nd line: sodium cromoglicate (mast cell stabiliser, takes weeks to work)
explain the pathophys of diabetic retinopathy and the findings on ophthalmoscopy
chronic hyperglycaemia causes damage to retinal vasculature and endothelial cells.
this increases vascular permeability, leading to:
- hard deposits
- blot haemorrhages
- microaneurysms
- venous beading
- cotton wool spots (nerve fibre damage, retinal infarction (pre-capillary arteriolar occlusion))
- intraretinal microvascular abnormalities
- neovascularisation