Opthamology Flashcards
(114 cards)
What are the causes of conjunctivitis? What are the clinical features of each?
Allergic - generalised redness, serous discharge, itchiness, bilateral
Viral (adenovirus, Herpes simplex) - unilateral, generalised redness, serous discharge
Bacterial (S.pneumoniae, S.aureus, H.influenzae) - generalised redness, itchiness, purulent discharge, foreign body sensation/gritty
What is the management of each cause of conjunctivitis?
Allergic - antihistamine eye drops
Viral - self limiting, don’t touch eyes, can use artificial tears
Bacterial - normally self limiting, chlorampenicol drops in severe cases
What type of HSV causes conjunctivitis and how?
HSV 1 normally but HSV2 in neonates from contaminaiton in vaginal delivery.
What is blepharitis?
Inflam of the eyelid = sore and itchy crusty eyelids. Is a chronic condition and can’t be cured. 50 yo = average presentation.
What are the causes of different types of blepharitis and some specific signs for each?
Ant - staph, seborrheic dermatitis. Trichiasis, poliosis, madarosis
Post - affects meibomian gland. dilated and obstructed meibomian glands, chalazion
What do these words mean:
Trichiasis
Poliosis
Madarosis
T = eyelashes turning in
P = depigmentation of eyelashes
M = loss of eyelashes
What is the management of blepharitis?
Can’t be cured but:
Conservative management - warm compresses and clean lids reg, avoid eye make up and contact
Medical - ocular lubricants, steroids or abx
Can refer if not resolving or suspect underlying condition, visual change/loss, cellulitis signs and eyelid deformity
What do entropion and ectropion mean?
Entropion = eyelid turning inwards
Ectropion = eyelid turning outwards
What is keratitis? What are the CF?
Inflam of the cornea.
CF - eye pain, watering, photophobia, reduced vision, hypopyon
O/E - corneal infiltrate and opacification
What are corneal infiltrates? What is epiphora?
What is hypopyon?
Gray haze around cornea, looks a bit like corneal arcus
Epiphora - excess tearing of eye
Hypopyon - collection of pus behind the cornea in the ant chamber
Herpes simplex keratitis:
- CF
- O/E
- Treatment
Pain, photophobia, epiphora.
Can see dendritic ulcers w fluorescein, most common cause of corneal blindness.
Topical acyclovir.
What is the pathophysiology behind central retinal artery occlusion?
Int carotid artery branches into the ophthalmic artery which supplies the eye. This splits into retinal (retina) and ciliary (choroid) arteries.
What is the presentation of CRAO?
- Sudden onset painless unilateral loss of vision due to ischaemia of the retina
- Central area of vision spared due to cilioretinal artery supply to the macula in 15-30% of cases
What are the signs of CRAO? (fundoscopy)
- Relative afferent pupillary defect - asymmetrical pupillary reaction to light due to optic nerve disease
- Pale retina
- Cherry red spot = macular sparing due to choroid maintaining blood supply
- Retinal emboli
What is the management of CRAO?
- Intra arterial thrombolysis - limited evidence
- Treat underlying causes eg. IV steroids for temporal arteritis
What are the complications of CRAO?
- Profound visual loss
- Cardiovascular disease burden, more likely to die from stroke
- Neovascularisation of ischaemic retina = vitreous haemorrhage or occlude ant chamber = glaucoma
What is the difference between CRAO and CRVO?
CRVO is more common than CRAO and has widespread hyperaemia and haemorrhages on fundoscopy = stormy sunset.
What are cataracts and what are the causes?
Opacity in the lens due to denatured protein/loss of crystallin.
Causes - increasing age, trauma, steroids, ant uveitis, radiation
What are the CF of cataracts?
- Blurred vision
- Sensitive to bright lights and glare
- Poor night vision
- Halos around lights
- Polyopia
- Reduction in colour intensity
- Loss of red reflex
- Can see white/grey pupil
- Nystagmus
What is the management of age related cataracts?
Replace the diseased lens:
- Phacoemulsification - break up diseased lens and aspirating the contents, then place a new lens into the remaining lens capsule (most common)
- Extra capsular cataract extraction = remove whole nucleus and aspirate lens cortex then insert rigid lens
What are the complications of cataracts surgery?
- Endophthalamitis - infection of the viterous/aqueous
- Corneal oedema
- Malposition of lens
- Retinal detachment
- Post capsule rupture and opacification
What are the causes of cataracts in children?
- Inherited
- Systemic disease eg. intrauterine rubella, DM, myotonic dystropy craniofacial syndromes
- Idiopathic
- Drugs
- Trauma - penetrating injury, electric shock, blunt trauma
Quite a rare cause of blindness in children.
What are some drugs that cause cataracts?
- Steroids
- Amiodarone
- Phenothiazines
What are the sx of cataracts that affect the subcapsular of the lens?
Near vision affected more than distance