Ophthalmology Flashcards
Describe how anterior uveitis presents
acute, painful red eye associated with photophobia and blurred vision
O/E: pupil is small + irregular; hypopyon [fluid level]. Visual acuity normal –> impaired
What condition is scleritis associated with?
Rheumatoid arthritis
Describe how scleritis presents
Severe, constant pain in eye
O/E: eye red + photophobia, visual acuity normal
How to differentiate episcleritis from scleritis
Pain
Pilocarpine mechanism of action
Pupil constriction (via agonist to muscarinic receptors)
works like the parasympathetic nervous system
Atropine mechanism of action
Pupil dilation (via anti-muscaranic/anti-cholinergic)
Like sympathetic NS
Risk factors for posterior vitreous detachment
Elderly
Short sighted!!!
Describe the presentation of posterior vitreous detachment
Floater on the temporal field of vision
Visual acuity is normal
Cupping of the optic disc is seen in what?
Glaucoma
What does fundoscopy reveal in central retinal artery occlusion
Chery red spot/macula
Pale retina
Describe a Holmes Adie pupil
Unilateral dilated pupil; slowly reactive to accommodation; poorly reactive to light
Absent ankle/knee jerks
How does retinitis pigmentose present?
Night blindness Tunnel vision (as peripheral retina affected)
What are some ocular manifestations of RA?
keratoconjunctivitis sicca (most common) episcleritis (erythema) scleritis (erythema and pain) corneal ulceration keratitis
Iatrogenic
steroid-induced cataracts
chloroquine retinopathy
What is the commonest ocular manifestation of RA?
keratoconjunctivitis sicca (dryness)
How do prostaglandin analogue eye drops work?
Increases uveoscleral outflow
How do beta blocker eye drops work in glaucoma?
Reduces aqueous production
How do Sympathomimetics (e.g. brimonidine, an alpha2-adrenoceptor agonist) eye drops work in glaucoma?
Reduces aqueous production and increases outflow
How do Carbonic anhydrase inhibitors (e.g. Dorzolamide, acetazolamide) eye drops work in glaucoma?
Reduces aqueous production
How do Miotics (e.g. pilocarpine, a muscarinic receptor agonist) work in glaucoma?
Acute: constrict pupil
Chronic glaucoma: Increases uveoscleral outflow
How does glaucoma cause visual loss?
Increased ocular pressure –> optic disc/nerve atrophy
Describe Argyll Robertson pupil
Small irregular pupils
No response to light, but can accommodate
[to remember - prostitute pupil - accommodates but doesnt react/have a good time]
(seen in neurosyphilis)
Initial investigation in age related macular degeneration?
Slit lamp microscopy
What 2nd line investigation if you suspect neovascular ARMD?
Fluoroscein angiography
Treatment for dry age related macular degeneration
Zinc + anti-oxidant vitamine (ACE)
Stop smoking
What charcaterises dry ARMD?
Drusen
how to measure pressure in the eye?
Tonometry
Why does orbital cellulitis require immediate admission/IV antibiotics?
risk of cavernous sinus thrombosis and intracranial spread
