AMD

Question 1

what is the major tissue effected by AMD?

Answer 1

RPE

Question 2

What fi, ndings your pt must have in order to have dry AMD ?

Answer 2

RPE changes, drusen, geographic atrophy
remember, hard drusen alone is not indicative of AMD
nor increase the likelihood of CNVM (choroidal Neovascularization)

Question 3

How do you define hard drusen ?

Answer 3

Drusen that are < 6m microns in diameter
they could be from a single RPE cell filed with lipid or
focal deposits of hyaline materials in Bruch’s membrane

Question 4

How do you differentiate between hard and soft drusen?

Answer 4

hard drusen are more superficial and shiny, small and well demarcated vs. hard drusen are deeper, duller, larger puffy and boarder not distinct

Question 5

what is the chances of dry AMD to progress ?

Answer 5

Mild AMD –> low risk, 7.1 % will progress in 5 years

Severe AMD –> high risk, 13-18% progress in 5 yr, which are seen wt bilateral soft drusen

Question 6

what can be used as an indication of progression to wet AMD?

Answer 6

number and size of drusens

Question 7

what is happening in the RPE changes?

Answer 7

• mottling or salt pepper appearance, darker and lighter spots are indicative of RPE changes.
• damaged RPE cells lose their pigment which is taken up by the healthy RPE cells –> the appearance of both hypo & hyper pigment background.

Question 8

how do you differentiate hard and soft drusen from RPE changes?

Answer 8

RPE changes the amount of pigment is constantly changing –> gives it darker and lighter appearance
- in drusen we only have hypo pigmentation –> we see lighter spots wt regular RPE appearance

Question 9

what is the most visually threatening of dry AMD?

Answer 9

Geographic atrophy esp. if closer to the macula

Question 10

what is geographic atrophy ?

Answer 10

large confluent atrophy of the RPE –> to atrophy of overlaying PR’s thus retina in general–> can see underlying choroidal vasculature

Question 11

what is the risk of geographic atrophy ?

Answer 11

CNVM ,
Any time we have a RPE defect, the tight junction that make up the blood retinal barrier is damaged and no longer prevent the blood from choroicapillaries getting into the retina

Question 12

what is the treatment plan for pts with geographic atrophy?

Answer 12

Low vision therapy

Question 13

what causes geographic atrophy ?

Answer 13

It is a result of adjacent RPE & PR cell death

Question 14

will anti VGEF helps in the case of geographic atrophy ?

Answer 14

no

Question 15

what causes education of vision in dry AMD?

Answer 15

Geographic atrophy accounts for 10% of blindness related 
to AMD ( = dry)

Question 16

what is the pathology of AMD?

Answer 16

• ischemia of retina and RPE due to dec. perfusion
• Senescence of the RPE
• RPE cell apoptosis due to inflammation & immune response
• Genetic factors effecting RPE or PR
• Accumulation of defective microglial cells , which support neurons, and ensure their well-being

Question 17

what is the most responsible iso-form for angiogenesis ?

Answer 17

VGEF - A

Question 18

where does a net in wet AMD originate from ?

Answer 18

Choriocapillaries

Question 19

is AMD unilateral or bilateral ?

Answer 19

there is a 43% chance of progression bilaterally but asymmetric

Question 20

what % of reduction in VA is done by drusen and RPE changes?

Answer 20

RPE changes and drusen are not major causes of VA reduction, which is a good news for pt
but the major threat to vision comes from geographic atrophy and CNVM

Question 21

Do all AMD bleeding look the same ?

Answer 21

No bleeding comes from 2 different layer , sub-retinal and sub-RPE.
bleeding is from the outer layer of the retina ( RPE, Choroid )
In AMD, blood starts to break through at the level of the RPE & depending on how much it breaks through & level of degradation of the RPE, is going to determine what its like to look like to us clinically

Question 22

Does all the bleeding look the same on PDR?

Answer 22

In PDR the inner vascular supply ( CRA) is leaking. so
in PDR the vessels growing typically superficially btw the virtuous face and the face of the retina, therefore they will almost look alike