Acute Red Eye Flashcards
what is the acute red eye?
painless= conjunctivitis, episcleritis, subconjunctival haemorrhage painful= glaucoma, anterior uveitis, scleritis, corneal abrasions or ulceration, trauma etc
what are cataracts?
lens opacification which reduces visual acuity by reducing the light that enters the eye
what are the symptoms of cataracts?
usually asymmetrical, very slow reduction in vision, progressive burring of vision, change in colour vision with colours becoming more brown or yellow, “starbursts” can appear around lights- particularly at night time
what is a key sign for cataracts?
loss of the red reflex- the lens can appear grey or white when testing the red reflex which might show up on photographs taken with a flash
when do cataracts present and what are the risk factors?
can be congenital but most develop over years due to risk factors: increasing age, smoking, alcohol, diabetes, steroids, hypocalcaemia
how are cataracts treated?
if symptoms are manageable then no intervention but can perform cataract surgery if needed which involves removing and replacing the lens
what is glaucoma?
optic nerve damage caused by a significant rise in intraocular pressure caused by a blockage in aqueous humor trying to escape the eye- there are 2 types= open angle and closed angle
what is the normal intraocular pressure and why is this created?
10-21mmHg and is created by the resistance to flow through the trabecular meshwork
what is the pathophysiology of open angle glaucoma?
can be a gradual increase in resistance through the trabecular meshwork making it difficult for aqueous humor to exit the eye causes slow onset
what are the risk factors of open angle glaucoma?
increasing age, FH, black ethnic origin, nearsightedness (myopia)
how does open angle glaucoma present?
often asymptomatic for a long time and usually diagnosed by routine screening, it affects the peripheral vision first and gradually closes until they get tunnel vision, also maybe headache, blurred vision and fluctuating pain
what happens to the optic disc due to increased pressure in the eye?
ophthalmoscopy view of the optic disc appears unhealthy, pale and cupped (small indent in the disc= optic cup becomes larger)
how is open angle glaucoma diagnosed?
raised IOP (Goldman applanation tonometry), optic disc changes (fundoscopy), visual field defects (visual field assessment)
how is open angle glaucoma managed?
prostaglandin analogue eyedrops (latanoprost) to reduce IOP= 1st line, beta-blockers carbonic anhydrase inhibitors can reduce production of aqueous humor
what treatment is given if eyedrops are ineffective?
traveculectomy surgery which involves creating a new channel
what is the pathophysiology of acute angle closure glaucoma?
iris bulges forward and seals off the trabecular meshwork from the anterior chamber preventing draining and the build up of pressure worsens the closure of the angle= ophthalmology emergency
what are the risk factors for acute angle closure glaucoma?
increasing age, females x4, FH, Chinese and East Asian (unlikely black), shallow anterior chamber
how does acute angle closeure glaucoma present?
sudden onset, red eye, teary, vision lost/blurred, headaches, fixed pupil size
how is acute angle closure glaucoma managed?
referred to opthalmologist and given pilocarpine eye drops (constrictor), acetazolamide (carbonic anhydrase inhibitor) to reduce the pressure but laser iridotomy is usually required as a definitive treatment (hole in iris to allow aqueous humor flow)
what is uveitis?
inflammation of the uvea (vascular layer of the eye= iris, choroid and ciliary body), can be anterior, intermediate or posterior
what are the causes of uveitis?
isolated illness, HLA B27 related conditions= ankylosing spondylitis, IBD, reactive arthritis (acute anterior uveitis), chronic AU= sarcoidosis, syphilis, TB, herpes
how does acute anterior uveitis present?
dull, aching, painful red eye, reduced visual acuity, watering eye with photophobia, floaters, exam will show cells in the anterior chamber
how is acute anterior uveitis treated?
topical steroids and dilating drops
what is scleritis?
inflammation of the full thickness of the sclera
