Eye disease Flashcards
in who is eye trauma more common
males 25-36 in machinery or assault
females >60 who have fallen
how many with poor outcome due to eye trauma have no light perception?
50%
what parts of eye should be examined in trauma
lids conjunctiva cornea anterior segment pupils fundus fluroscien
golden rules of eye trauma?
hx key take visual acuity fluroscein drops handle globe rupture with care Xray or CT IORB irrigate chemical injuries
what may cause blowout fracture and what is a consequence
trauma to globe or to orbital rim may transmit to orbital plates
can trap inferior rectus and patient may not be able to look up
may cause subconjunctival haemorrhage
what is hyphaemia
blood in ant chamber or in vitreous cavity leaking in
can circulate around but if enough then will settle
describe the process of traumatic retinal detachment
slight tear of retina causes vitreous to get behind and cause total detachment
how can a corneal lateration or penetrating injury present
aqueous leaking out, ant chamber flat/shallow
iris may be pulled into wound to cause irreg pupil
what is siedels test
use of fluroscein to determine corneal penetration as it is diluted by aqueous
what is sympathetic ophthalmia
injury to one eye leads to AA uveitis in both eyes due to systemic exposure of intraocular antigens
can lead to bilateral blindness
what may cause small particle corneal damage
hammer and chisel
machinery
management of corneal abrasion or small particle in eye
slit lamp/local anaesthetic
use edge of needle to scrape out
chloramphenicol ointment 4x daily for 1 week
what may raise suspicion of anterior chamber penetrating injury
irreg pupil
shallow ant chamber
localised cataract
gross inflammation
what may cause intra-ocular penetrating trauma and what must be done
hammer and chisel or other fast moving objects
always X ray/CT
what is the china white sign
ischaemia and white areas caused by alkali destruction of blood vessels
alkali damage can cause corneal vascularisation - what is this?
blood vessels growing over cornea following alkali damage
true/false - acid burns are more penetrating than alkali
false - alkali generally have better penetration and can cause corneal/conjunctival scarring
management of chemical burns to the eye
quick Hx with nature of chemical check its not cement or lime check toxbase and pH irrigate with 2L saline or until pH normal assess at slitlamp
prevention of eye trauma?
safe practice
eyewear
education
what is papilloedema
optic disc swelling in response to raised ICP
what should optic disk swelling be suspected as
always suspect as SOL until proven otherwise
what is a consequence of increase in volume in intercranial cavity
herniation of brainstem through foramen magnum
may lead to cord compression, brainsrem compression and death
common vascular cause of papilloedema
malignant hypertension
functions of CSF
maintains stable extracellular environment buoyancy mechanical protection waste removal nutrition
what happens in chronic optic disk swelling
swelling subsides and disk becomes atrophic and pale
may lead to lost visual function and blindness
what is idiopathic intercranial hypertension
common cause of bilateral disc swelling in young females
may be due to blocked CSF absorption or obstructed CSF circulation
what may cause CSF blockage to absorption in IIH
vitamin A
microemboli in superior sagittal sinus
what may cause obstructed CSF circulation in IIH
increased intra abdo pressure - ie obesity
stenosis of transverse cerebral sinuses
what is ischaemic optic neuropathy, how does it present and what is an associated condition
occlusion of posterior ciliary arteries causing occlusion of optic nerve head circulation
sudden, painless visual loss with swollen optic nerve
associated with temporal arteritis
cause of CRAO
carotid artery disease
emboli from heart
presentation of CRAO
painless sudden visual loss
RAPD
pale, oedematous retina with thread like vessels
other forms of CRAO
branch retinal artery occlusion
amaurosis fugax
what is amaurosis fugax
painless vision loss lasting around 5 mins
nothing on examination
refer to stroke clinic
cause of CRVO
diabetes
hypertension
cancer
virchow’s triad
signs and symptoms of CRVO
sudden visual loss
retinal haemorrhage
dilated, tortuous veins
optic disc and macula swelling
signs and symptoms vitreous haemorrhage
sudden loss of vision floaters loss of red reflex haemorrhage on fundoscopy identify cause
cause of vitreous haemorrhage
retinal vein occlusion, diabetes lead to angiogenesis with leaky blood vessels
retinal tear leading to disrupted blood vessel
presentation of retinal detachment
painless loss of vision with flashes/floaters
may have RAPD
tear on fundoscopy
what is Wet ARMD
new blood vessels grow causing build up of fluid and scarring
presentation and management of wet ARMD
rapid loss central vision, metamorphopsia, scotoma
haemorrhage, exudate
intra-vitreal VGEF
what is closed angle glaucoma
aqueous humour encounters increased resistance through iris/lens channel leading to peripheral iris to bow forward and obstruct trabecular meshwork
presentation of closed angle glaucoma
painful red eye sudden visual loss headache nausea and vomiting cloudy cornea dilated pupil
causes of gradual visual loss
ABCDG dry ARMD Blur - refractive error cataract diabetes glaucoma
what is a cataract
clouding of lens - often age related
management of symptomatic cataracts
intra-ocular lens implant
presentation and management of dry ARMD
gradual vision decline
scotoma
druden, atrophic retina
supportive with low visual aids, social support, registered blind
signs/symptoms of open angle glaucoma
often none and may be incidental
cupped disc
visual field defect
how many layers does the retina have
10
pathogenesis of diabetic retinopathy
diabetes leads to high sorbitol, outpouching of retinal blood vessels to cause microaneurism, haemorrhage, deposition fo exudate
high sorbitol makes blood more viscous so there is slowed flow and ischaemia
VGEF leads to angiogenesis, which can lead to retinal traction
features of mild/moderate non-proliferative diabetic retinopathy
microaneurism
hard exudates
small intraretinal haemorrhage
features of severe non proliferative diabetic retinopathy
cotton wool spots
venous bleed
how can severe non-proliferative diabetic retinopathy be managed
laser therapy
management of diabetic macular oedema
anti-VGEF
used to be laser
consequence of proliferative diabetic retinopathy
vitreous haemorrhage and retinal traction
findings on fundus of pathological myopia
lacquer crack subretinal haemorrhage fuch's spot RPE/ choroid haemorrhage cystoid, paving stone, lattice degeneration retinal thinning with holes scleral thinning
diagnostic criteria for pathologic myopia
spherical equivalent >-8.00D or axial length >26mm
what retinal tears need to be treated in case of retinal detachment
horseshoe tears or total dialysis
what is a rhegmatogenous PVD
retinal break leads to retinal detachment
what is a non-rhegmatogenous PVD
traction or exudate forms scar tissue or exudative fluid that pushes off the retina
cause of traction leading to retinal detachment
diabetes
cause of exudative retinal detachment
choroid tumours post scleritis haradas toxaemia of pregnancy hypoproteinaemia RD surgery excess retinal photocoag choroid neovascularisation uveal effusion
signs of exudate behind retina?
convex, smooth elevation
may be mobile with fluid shift
what is central serous chorioretinopathy
small, focal RPE leak
young pt, male, healthy, 30-50, executive job
most recover, some recur
causes of cystoid macular oedema
postop uveitis retinal venous occlusive disease choroid neovascualrisation epiretinal membrane retinitis pigmentosa
Ia macular hole?
foveolar detachment
II macular hole?
full thickness defect <400mm
III macular hole
full thickness defect >400mm
IV macular hole
stage III with PVD
