Acute visual disturbances Flashcards
is macular degeneration reversible?
no
what types are MD are there?
dry and wet
what is characteristic of dry MD?
drusen (yellow lipid depositis behind retina)
atrophy of retinal pigmenet epithlium
sow progression
less dramatic
what vision is lost in MD?
central vision
what is characteristic of wet MD?
accumulation of fluid heamorrhages scarring macular thickening swelling develops dramatically
who tends to get MD?
over 50 yrs
its 3rd most common cause of blindness worldwide
what are the risk factors of MD?
age smoking alcohol sun exposure poorly balanced diet
How does MD present?
disturbed central vision - blurring, scotoma, distortion
difficult reading fine print, recognising faces and appreciating fine detail
distortion on Amsler grid testing
Fundsocopy - drusen, atrophy, scarring, pigmentation and in wet -haemorrhages
when do you refer dry and wet MD pts to specialist?
dry - routine referral if pt symptomatic
wet - within 2 weeks if new signs seen
what is the tx for MD?
NO CURE!
lifestyle modifications - stop smoking, reduce alcohol, better diet, minimise sun exposure
supportive management - magnifiers, light modifications
wet AMD- minimise angiogenesis, give anti-VEGF (i.e ranibizumab aka ‘lucentis’) via intra vitreous injections
what are the risk factors for posterior vitreous detachment?
age myopia (short sighted) uveitis intraocular laser or surgery treatment eye trauma
what are the symptoms of PVD?
floaters
photopsia - percieved flashes of light
painless
no visual impairment
vitreous haemorrhage - shower of black spots (vitreous heamorrhage is associated with retinal detachment)
what signs can be seen with PVD and what instrument do you use to see the signs?
weiss ring
sometimes haemorrhage
use a slit lamp
what tx is availabe for PVD?
PVD usually caused by retinal tear - laser repair
vitreous hemorrhage clears spontaneously but if very large may require surgery
if flashes persist - vitrectomy
Is retinal detachment a medical emergency?
YES!!!!
What three types of retinal detachment are there?
rhegmatogenous - tear in retina allows fluid to accumulate under retina separating it from retinal pigment epithelium which nourishes the retina. this is most common type
tractional - scar tissue pulls retina away from RPE
exudative - caused by trauma/inflammatory disorders. fluid accumulates but no tear present.
what are the risk factors for retinal detachment?
any age but more common >40 males white short sighted (myopia) diabetic hypertensive retinal detachment in other eye fhx cataract rugery uveitis eye injury
what are the symptoms of retinal detachment?
increase in floaters
light flashes in eye
sometimes curtain over field of vision
signs are seen through fundoscope
how do you treat retinal detachment?
laserm(thermal)/cryopexy (freezing) to repair tear
pneumatic retinopexy - small gas bubble injected into eye and then laser or cryopexy used to seal tear
scleral buckle -sew silicone buckle around sclera to put pressure which allows tear to heal - seal with laser or cryopexy
vitrectomy - remove vitreous and replace with saline solution if large tears present
these treatments can be used in combination
what is amaurosis fugax?
transient monocular blindness (curtain over one eye)
lasts for secs-mins, painless
males with cv/stroke risk factors or hx of stroke are at risk
vision returns to normal afterwards
no tx - tx underlying cause
what is optic neuritis?
inflammation of the optic nerve - it is a recurring condition
who is at risk of optic neuritis?
females
20-40yrs
what are the causes of optic neuritis?
often unknown
could be autoimmune - MS
infection/trauma/arteritis/diabetes/glaucoma/compressive lesions?
what are the signs and symptoms of optic neuritis?
vision loss ussually in one eye that develops over hours-days. it peaks at 1-2 weeks
variation in how blind the eye becomes
reduced visual acuity
reduced colour vision
loss of contrast
change in peripheral vision
pain
vision worsened by heat/exercise and pain worsened by eye movement
usually temp but can be perm
swelling of optic nerve and enlargement of blood vessels=papillitis
RAPD SEEN IF ONLY ONE EYE AFFECTED AND OTHER EYE NORMAL
nb: inflammation can be retrobulbar in 2/3 pts meaning that no signs can be seen when using an opthalmoscope = retrobulbar neuritis
