fundus autoflorescence

what is lipofuscin

flourescent that accumulates in the RPE

byproduct of photoreceptor outer segments that have been phagocytosed

when does fundus autoflourescnce occur

when lipofuscin excited by short to med wavelength visible light

how can you detect lipofuscin

-confocal scanning laser ophthalmoscope

-fundus autoflourescence camera system

-fundus spectrophotometer

what is the wavelength of lipofuscin

300-600nm

what kind of laser stimulates lipofuscin

low energy

what is the purpose of a barrier filter in AFA

allow only the RPE lipofuscin response to pass

what can AFA do

perform 30 scans & provide an avg calculated result

provides a single monochromatic images with contrast

what does the wideband barrier filter of fundus autofluorescence camera do

allows the lipofuscin response to pass through it before reaching the sensor of the retinal camera

high concentration of lipofuscin

hyperfluorescent signal

absence of lipofuscin appears as

hypofluorescent signal

how does normal fundus appear?

bc there is normal amount of lipofuscin in the RPE → ocular fundus appear diffuse, midly hyperfluorescent

what structures in the eye appear hypoflurescent

optic nerve

blood vessels

fovea

what do hypofluorescent signal

-RPE atrophy

-fresh hemorrhages

-exudative lesions

-areas of dense hyperpigmentation

-some types of hard drusen

what do hyperfluorescent signal

• yellow lesions → best’s and stagardt’s disease

• older hemorrhages

• soft drusens

how do RPE tear appear

center: well demarcated → hypo fluorescence

edges: retracted → hyper-fluorescence

central serous choriotetinopathy

acute exacerbation of CSCR presents a macular detachment w/ hyper-fluorescence at the margin & inferior zone of detachment

in simpler terms: fluid build up → macular detachment → hyperfluorescence due to fluid leaking under the retina → most notable at inferior zone

age related macular degeneration

• For dry AMD, there’s no cure, but some people use vitamins or dietary changes to slow progression.

• For wet AMD, doctors may use treatments like injections, lasers, or photodynamic therapy to stop the blood vessels from leaking.

While AMD doesn’t cause total blindness, it can make everyday tasks like reading or driving difficult, especially in its later stages.

stargardt disease

hyperfluorescent flecks with peripapillary sparing

appear as flecks surrounding a hypofluorescent central macula related to chorioretinal atrophy

what is the most common form of inherited macular degeneration in young people

stargardt disease

retinitis pigmentosa

robson-holder ring: border of active outer segment dysgenesis and abnormal lipofuscin production

what does robson-holder ring represent?

area where retina is active but damaged

retina is trying to work here but it is starting to break down

what is mottle hypoflourescence

Outside the ring

dark, uneven areas

area where photoreceptor cells are dead or severely damaged.

The dark spots mean the retina is no longer working properly in those areas.

best disease

genetic eye disorder that affects the macula

- mutations in the BEST1 gene, which leads to abnormal deposits of material under the retina, disrupting normal vision

what are the different stages of best’s disease

1. previtelliform

2. vitelliform

3. pseudohypopyon

4. vitelleruptive

5. atrophic

6. choroidal neovascularization

stage 1 - previtelliform

normal vision

subtle RPE changes

stage 2 - vitelliform

egg-yolk appearance

normal vision to mild vision loss

stage 3 - pseudohypopyon

layering of lipofuscin

normal to mild vision loss

stage 4 - vitellereptiove

break up of material

“scrambled egg”

stage 5 - atrophic

central RPE & retinal atrophy

20/30 → 20/200

stage 6 - CNV (choroidal neovascularization)

occurs in about 20% pts

significant decrease (20/200 or worse)