Opthalmology Flashcards
arcuate scotoma suggests what pathology
glaucoma
central scotoma visual field defect suggests what?
macular degeneration
macular oedema
or optic nerve pahtolgy
right temporal lobe lesion would cause what visual field defect?
left superior quadrantanopia
having a complete lesion on the optic nerve causes what visual defect?
what about the direct and indirect pupillary reflexes?
total blindness in that eye
direct absent, indirect intact
optic chiasm lesion will cause what visual defect?
bitemporal hemianopia
lesion on the optic tract causes what visual defect
a contralateral homonymous hemianopia
lesion on the optic radiation causes what visual defect
a contralateral homonymous hemianopia
damage to tip of the occipital lobe causes what visual defect
contralateral homonymous hemianopia
causes of visual cortex field defects
ischaemia [TIA, migraine, stroke] glioma meningioma abscess AV malformation drugs: ciclosporin
what is a cataract?
opacity of the lens
risk factors for cataracts
age DM [appear earlier] genetic steroids high myopia myotonic dystrophy smoking alcohol ^sunlight trauma radiotherapy HIV
is there red reflex in cataracts?
immature: yes
dense cataracts: no
how do cataracts present in adults and in children
gradually worsening blurred vision
dazzle, difficulty driving at night
if unilateral, often unnoticed
children: white pupil, squint, nystagmus, amblyopia
cataract Mx
mydriatic drops
sunglasses
surgery
Mx of congenital cataract
R/F immediately to prevent deprivation amblyopia
TORCH screen
causes of a red eye that requirke urgent referral
acute glaucoma
acute iritis
corneal ulcers
scleritis
common causes of red eye
conjunc
foreign body
corneal ulceration
subconjunctival haemorrhage
what causes acute closed-angle glaucoma
angle of the anterior chamber narrows causing sudden rise in intraocular pressure
risk factors/ causes of acute closed angle glaucoma
shallow anterior chamber thick lens thin iris/ciliary bodies hypermetropic cyclopentolate traumatic haemorrhage
peak age incidence of acute closed-angle glaucoma
40-60
how does acute closed angle glaucoma present?
N+V headache painful red eye night blurred vision halos around lights at night
what should be avoided in acute closed-angle glaucoma patients and why?
dark room or patch - will worsen the angle closure by dilatation of the pupil
Mx of acute closed-angle glaucoma
BB pilocarpine acetazolamide [analgesia, antiemetics] peripheral iridectomy
complications of peripheral iridectomy surgery [for acute closed-angle glaucoma]
visual loss
central retinal artery or vein occlusions
repeated episodes
what are the 2 types of diabetic retinopathy and how are they distinguished
proliferative and non-proliferative
proliferative = new vessels on the retina [neovascularisation]
signs of non-proliferative diabetic retinopathy
microaneurysms [dots] haemorrhages [blots] hard exudates [yellow patches] engorged tortuous veins cotton wool spots
what can non-proliferative diabetic retinopathy progress to?
sight threatening proliferative DR
signs in proliferative diabetic retinopathy
fine new vessels on optic disc, retina
vitreous haemorrhage
what is maculopathy in diabetic retinopathy?
leakage of vessels close to the macula - causing oedema and vision loss
when + how often should diabetics have eyes screened
at diagnosis and annually
define glaucoma
optic neuropathy with death of many retinal gangion cells and their optic nerve axons
[IOP may be raised but this isnt part of the definition!]
risk factors for glaucoma [chronic simple open-angle]
^IOP african-caribbean FH ^age myopia thyroid eye disease DM eye disease
what is required for glaucoma diagnosis [CSOAG]
IOP visual fields central corneal thickness optic nerve /fundus exam Gonioscopy
screening for glaucoma
tonometry [pressure]
visual fields
optic disc exam
Mx of COA glaucoma
drops: prostaglandin analogues (latanoprost) B blockers (timolol) alpha agonists (apraclonidine) miotics (pilocarpine)
laser therapy
surgery
systemic drugs that can cause glaucoma
steroid drops
mydriatics
anticholinergics [tricyclics, some parkinsons drugs]
risks of steroid eye drops (used in allergic eye disease)
^ocular pressure
cataract formation
propagate a missed dendritic ulcer > blind
Mx of diabetic retinopathy
BP control DM control laser photocoagulation Triamcinolone anti-VEGF drugs [Vascular endothelial growth factor]
what factors may accelerate diabetic retinopathy
pregnancy smoking dyslipidaemia ^BP renal disease anaemia
describe subconjunctival haemorrhage
blood behind conjunctiva from small bleed
harmless
differences between scleritis and episcleritis [how common? how dangerous?]
episcleritis common, scleritis rare
episcleritis benign, scleritis sight-threatening + ass. w/ systemic disease
how to differentiate scleritis and episcleritis on examination
episcleral vessels move with cotton bud and blanch with phenylephrine. Scleral won’t.
Sx of episcleritis
red eye acute onset dull ache, tender wedge of engorged vessels acuity ok
Mx of episcleritis
articficial tears
topical/ systemic analgesia [NSAIDs]
presentation of scleritis
red eye pain bores into back of eye painful ocular movements headache photophobia
Mx of scleritis
NSAIDs PO
pred PO
cyclophos/ritux if posterior/ necrotizing
surgery if imminent globe perf
differentials for a red eye
foreign body episcleritis scleritis subconjunct. haemorrhage conjunctivitis corneal ulcer uveitis acute glaucoma
what does the anterior uvea comprise of
iris and ciliary body
give 3 system diseases that cause or are ass. w/ uveitis
ank spond sarcoid IBD reactive arthritis herpes TB syphilis HIV MS lymphoma
Sx of anterior uveitis
red eye pain blurred vision photophopia ^lacrimation small or irregular pupil
what would be seen on slit lamp in anterior uveitis
leucocytes in the ant chamber
Mx of anterior uveitis
pred drops
cyclopentolate [keep pupil dilated]
control underlying disease
[inflix]
Sx of conjunctivitis
red inflamed eye itch burn tears, sticky discharge acuity NOT affected
give 5 causes of conjunctivitis
allergy virus [adenovirus] gonococcal contact lenses autoimmune
Ix in conjunctivitis
conjunctival cultures [in neonatal/ chlam/ gon/ refractive]
Mx of conjunctivitis
viral - artificial tears
allergic - antihist drops
bact - topical chloramphenicol/ fusidic acid [but self limiting]
how would you help diagnose a corneal abrasion/lesion/ulcer?
fluorescin drops and blue light
[lesions stain green]
define keratitis
corneal inflammation- white area on cornea [collection of white cells]
causes of corneal ulcers
bacterial herpetic fungal [candida, aspergillus] protozoal vasculitis [e.g. in RA]
management of opthalmic shingles
aciclovir
Mx of non-herpetic corneal ulcers: 1 Ix, 2 Tx and what nerve would you examine?
cultures
chloramphenicol drops
ofloxacin drops
OR cefuroxime + gent
steroid drops
trigeminal nerve
ocular causes of headache
acute closed angle glaucoma
ant uveitis
Optic neuropathy is damage to the optic nerve from any cause. Give 4 causes of optic neuropathy
GCA non-arteritic anterior ischaemia optic neuropathy meningitis compression trauma inflamm/autoimmune genetic
findings in optic neuropathy
monocular partial or complete blindness central scotoma afferent pupillary defect colour blindness papillitis -> optic atrophy
unilateral loss of acuity over hours to days, with red destauration [reds appear less red], eye movements hurt. Diagnosis
optic neuritis
45-80% of optic neuritis patients develop what condition over the next 15 yrs
MS
causes of optic neuritis
MS syphilis DM vit deficiency leber's optic atrophy
Mx of optic neuritis
methylpred 72 hrs then pred for 11 days
give 3 causes of transient vision loss
vascular [atherosclerosis/emboli] migraine MS glaucoma papilloedema
dramatic unilateral visual loss in seconds. Afferent pupil defect. Retina appears white with cherry red spot at macula
central retinal artery occlusion
what nerves are responsible for afferent and efferent pupil light reflex?
what nerve is responsible to pupilary dilatation
afferent optic
efferent oculomotor
parasympathetic [ciliary nerves]
causes of afferent pupil defect
[optic nerve not receiving light]
optic neuritis
optic atrophy
retinal disease
causes/associations of retinal vein occlusion
atherosclerosis ^BP DM polycythaemia glaucoma ^age
Mx of retinal vein occlusion
photocoagulation [laser]
anti-VEGF injections
what causes vitreous haemorrhage
neovascularisation in DM or retinal vein occlusion
trauma
retinal tear
retinal detachment
give 5 causes of sudden monocular vision loss
retinal detachment acute glaucoma migraine optic neuropathy optic neuritis GCA central retinal artery occlusion retinal vein occlusion
what is a consensual pupil response
constricts when light shone in other eye
which muscles cause the down and out eye of 3rd nerve palsy
superior oblique
lateral rectus
causes of 3rd nerve palsy
cavernous sinus lesions superior orbital fissure syndrome DM posterior communicating artery aneurysm tumour HTN
what runs through the cavernous sinus?
CN 3,4,5,6
ICA
what is the pathogenesis of horners syndrome. Give some causes of this
disruption of sympathetic nerves
posterior inferior cerebellar artery/ basilar artery occlusion MS cavernous sinus thrombosis pancoast's tumour [NSCLC at apex] hypothalamic lesion cervical adenopathy mediastinal mass aortic aneurysm
child with inflamed eye, fever, lid swelling, reduced eye mobility, double vision, painful eye movements, proptosis, chemosis. Diagnoiss?
orbital cellulitis
complicaitons of orbital cellulitis
absecesses [subperiosteal, orbital] visual loss[ optic neuritis, retinal vein/artery occlusion] meningitis brain abscess sinus thrombosis
Mx of orbital cellulitis
Abx as per local guidelines
2 ways in which vision is lost in acute glaucoma
optic nerve damage
central retinal artery occlusion
commonest cause of viral conjunctivitis
adenovirus
red eye, painful to the point the patient cant sleep, with Hx of RA
scleritis
how is vision lost in scleritis
thinning and perforation of the sclera
how does pupil look in acute glauc vs anterior uveitis?
glauc = dilated
ant uve = constricted
ank spond, red eye
ant. uveitis
patient describes vision DISTORTION. what part of the eye is affeted?
macular
sudden or insidious for wet vs dry macular degen
wet sudden [bleed]
dry = insidious
what is responsible for the neovascularisation in wet MD and DM retinopathy?
ischaemia leads to VEGF release
Mx of the neovascularisation in wet MD and DM retinopathy
antiVEGF injections
what is the idea behind laser for DM retinopathy? what’s the downside?
burn the peripheral retina where new vessels are growing. sacrifice periperal vision for the sake of preserving central vision
flashes and floaters indicate
retinal detachment
cherry red spot =
central retinal artery occlusion
“blood and thunder” appearance and diffuse retinal haemorrhages =
central retinal vein occlusion
swollen optic disc and multiple flame haemorrhages
HTN Retinop/ papilloedema
6th nerve palsy often caused by what brain pathology
^ICP
why NGT in DKA?
gastroparesis
