posterior segment and the retina Flashcards
3 main layers in the retina from out to in
retina>RPE>choroid
3 parts of retina and function
- macula - cones, fine and color vision
- fovea - thinned center of macual - fine vision
- peripheral - rods
def. age realted macular degen.
- aquired degen disease of all 3 layers
- leads to deposition of drusen and loss of ovrlying receptors
- central vision loss
why is AMD important
leading cause of visual loss in >65
2 types of AMD
- wet
2. dry
what is Sx and prev of AMD
90%
Sx - mild central vision loss
4 signs of AMD
- drusen
2 pigment abnormalities
3 geography atrohy - serous pigment abnormalities
what is wet AMD
10%
- abnormal blood vessel growth from choroid to subRPE
- leads to hemmorage, fluid, fibrosis
- can cause dense central scotoma
how to confirm wet AMD (2)
- IV flouro
- optical CT
2 stages of preventions for dry AMD
1ry - sunglasses, quit smoking, diet?
2ry - vitamins
AMD risk factors
- age
- fam Hx
- smoking
- whites
- female
- diet
what is only use of vitamins
dry AMD for stages 3-4
4 Sx of wet AMD
1 . central and paracental blunting
- metamorphosia
- loss of visual acuity
- alterations in color perception
how to monitor dry AMD for progression
amsler grid - tells you it;s getting better or wet
main therapies for wet AMD
anti-VEGF
goal of anti-VEGF
prevent further vision loss
what happens to the vitrous with age
becomes more liquid and can begin to lose matrix
3 poss. effects of matrix loss
- posterior vitreous detachment - causes increases tractions at the vitreoius base
- retinal tear - liquid vit. travels under the retinal break and may lead to detachment
- retinal detachement - separation of retina from RPE leads to hypoxia and visual field defect
Sx of retinal detachment
- flashing lights
- floaters
- visual field defect
treatment of retinal tear
laser to hold it in place with the scarring
treatment of retinal detachement
surgery to reattach and prevent further visual loss
what is the choroid
posterior to retina
- high flow vascualr network
2 possible baddies of the choroid
- choroiditits - most often to toxoplasmosis
2. choroidal melanoma - tumor arising from melanocytes
