age-related macular degeneration Flashcards
what
degeneration in macula, causing progressive deterioration of vision
most common cause on blindness in UK
key finding
drusen on fundoscopy
2 types
wet dry (90% cases)
Wet AMD has worse prognosis
4 layers of macula
choroid layer - bottom
bruch’s membrane
retinal pigment epithelium
photoreceptors - top
choroid layer
contain blood vessels providing macula blood supply
what are drusen
yellow deposits of proteins + lipids between retinal pigment epithelium + bruch’s membrane
can be normal - if small and hard
features common to both wed and dry AMD
drusen
atrophy retinal pigment epithelium
degeneration of photoreceptors
wet AMD
development of new vessels growing from choroid layer into retina
they can leak fluid or blood, causing oedema and more rapid vision loss
what stimulates new vessel development in wet AMD
vascular endothelial growth factor (VEGF) stimulated the new vessel development
risk factors
age smoking white or chinese ethnicity FHx CVS disease
visual changes
worsening central visual field loss
reduced visual acuity
crooked/wavy appearance to straight lines
if wet AMD - presents more acutely
OE
reduced acuity - snellen chart
scotoma
amsler grid test shows distortsion straight lines
fundoscopy - drusen
scotoma
central patch of vision loss
slit-lamp biomicroscopic fundus examination
done by specialist to diagnose AMD
diagnosing wet AMD
optical coherence tomorgraphy
