Assessment, Classification, Grading and Referral of AMD Flashcards
In Fundus Autofluoresence, what appears as hyperfluorescence and what appears as hypofluorescence
Oxidative stress: hyperfluorescent
Causes lipofuscin to fluoresce
RPE cell death: hypofluorescent
what is Fluorescein Angiography used for
Investigate retinal leakage
Pattern of leakage used to classify lesion
what is Indocyanine Green Angiography used for
Images the choroidal vasculature
name 2 advantages of OCT angiography
Non-invasive and quicker than FA
Detects blood flow and abnormal patterns of vascular flow
what are drusen
Extracelluar deposits between RPE and BM, resulting from incomplete processing of photoreceptor outer segments, largely composed of lipids
Act as a barrier - affects waste removal from photoreceptors to the choriocapillaris
what is Cuticular Drusen also known as
Baso laminar drusen
how do Cuticular Drusen appear in oct and what is it a precursor to
usually many but small lesions 25-35 microns
the height of the druse = the diameter of the druse at its base
precursor to a vitelliform lesion which can cause a CNV
where does Reticular (pseudo)drusen appear in the retina
an accumulation of material
in the sub retinal space (rather than between the RPE and Bruch’s membrane)
there is more accumulation in the para and peri foveal region where there’s greater rod density
how large are Reticular (pseudo)drusen and what can they end up developing into
~100 microns
develop into type 3 CNV
which types of atrophy are more likely to progress more rapidly
the ones with more hypoflourescence around it such as diffuse and banded type patterns
name 2 types of atrophy that are more slower at progressing and why
focal and patchy
they have fewer areas of hypoflourescence
List 7 OCT features of AMD apart from GA and CNV
Subretinal fluid Intraretinal fluid Pigment epithelium detachment (PED) Hyper-reflective dots (HRD) Subretinal hyper-reflective material (SHRM) Double layer sign (DLS) Outer retina tubulation (ORT)
list the 4 different types of PED
Serous
Drusen
Fibrovascular
Haemorrhagic
name this feature on oct
drusenoid PED
name this oct feature
fibrovascular PED
fibrous material beneath the RPE
what oct feature is this
what size are they
where in the retina are they present
what can they indicate
Hyper reflective dots HRD 20-40 microns - quite small Can be present in all retinal layers Usually located around fluid can indicate an active neo-vascular membrane
what oct feature is this
what 4 things is it caused by
Sub retinal hyper reflective material caused by: Haemorrhage Lipid Pigment Subretinal fibrosis
what oct feature is this
what does it appear as
what 2 pathologies can it be present in
Double layer sign DLS
Irregular elevation of RPE from Bruchs
Can be present in CSR, subtypes of AMD e.g. PCV, non-exudative CNV
what oct feature is this
what do they represent
how do they appear in oct
what is it a sign of
Outer retinal tubules
Degenerative photoreceptors and Muller cells
Hyper-reflective ring, hypo-reflective centre - with intra retinal cysts/fluid
Sign of chronicity and poor response to Tx
what oct feature is this
where in the retina is it found
how does it appear on FA
Type 1 CNV
found below the RPE
a fibrovascular PED
has minimal changes and not much leakage seen on FA = occult or minimally classic
what oct feature is this
where in the retina is it found
how does it appear of FA
what other conditions is it also seen in
what happens when the lesion disrupts the RPE
Type 2 CNV
Above the RPE
in FA it shows greater leakage = classic
the lesion is focal with no widespread disruption
also seen in myopic or inflammatory lesions
once the lesion disrupts the RPE - it starts to enter the intra retinal space
what oct feature is this
where in the retina is it found
how does it appear on oct
Type 3 CNV
intraretinal NV
disruption to the RPE with hyper reflective material and hypo reflective intra retinal oedema
