This document discusses fundus autofluorescence, which maps the metabolic function of the retinal pigment epithelium (RPE). It explains that lipofuscin, a byproduct of phagocytosis in the RPE, is a major source of autofluorescence. Increased lipofuscin accumulation is implicated in aging and retinal diseases. Fundus autofluorescence imaging allows evaluation of spatial and temporal changes in lipofuscin distribution, providing insight into disease progression and prognosis. Specific autofluorescence patterns are described for various retinal conditions, and its utility for monitoring treatment effects is discussed.

1. FUNDUS
AUTOFLUORESCENCE
DR.SHAH-NOOR HASSAN FCPS,FRCS
Consultant, Vitreo-Retina
Bangladesh Eye Hospital & Institute

2. Fluorophore

3. Autofluorescence
 Some materials contain a naturally
autofluorescent component that can be
visualised when excited with a light of
particular wavelength

4. Retinoid Fluorophores

5. RPE and lipofuscin
 RPE constitutes a monolayer of
polygonal cells between the
choroid and neuro-sensory
retina
 Multiple functions
 RPE dysfunction implicated in
variety of retinal diseases
 LF is a byproduct of
accumulation of sheded outer
segments of the photoreceptors

6.  Lipofuscin accumulates as a byproduct
of phagocytosis of photoreceptors’ outer
segment
 In advanced age: It may occupy 20% of
free cytoplasmic space of RPE cells
The older we grow the more we glow

7. lipofuscin
 WHY IS IT DANGEROUS ?
 A2-E (N-retinylidene-N-retinylethanol-
amine) the dominant fluorophore possess
toxic properties
 Interferes with the normal cell function
 Precursors of A2-E are also toxic
 Products of photo-oxidation of RPE
lipofuscin serves as trigger for
complement activation inflammation

8. Fundus Autofluorescence
 Major source of fundus
autofluorescence is the lipofuscin of the
RPE

9. Fundus autofluorescence
 Metabolically mapping the RPE
 Developed as a tool to evaluate the RPE
during aging and ocular disease
Andrea von Ruckmann, Fredrick W. Fitzke and Alan C. Bird- Moorfield’s
eye hospital

10. Scanning Laser
Ophthalmoscope
 Webb and co-workers
 55° of field in one frame
 Low power laser source
 Scan in x and y axis
 Confocality ensures that light fluorescence
and reflectance is derived from same ocular
plane
 HRA2: Excitation 488nm
Emitted light above 500nm

11. FAF image acquisition
ART Mean image
Live image
FAF image
OCT image

12. FAF image acquisition
 Align the camera using the IR
illumination.
 Spectralis HRA+OCT only: Once you
see a sharp well-focused image,
change to Redfree illumination to fine-
tune focus.
 Change to the FA illumination. The
image will now be considerably darker.
 Automatic (recommended!) or
manual (Spectralis HRA+OCT only)
sensitivity control will outline the
retinal blood vessels.
Turn
or
automatic

13. FAF image acquisition – Mean
function
 Activate the ART (Automatic Real
Time) Mean function to generate a ‘live
Mean’ Autofluorescence image online
and view it as it is created.
 Note: Following the injection of
fluorescein dye, it will be impossible to
perform FAF imaging.
Press

14. Normal Autofluorescence
distribution
 Optic nerve head
 Absence of
autofluorescent pigment
 Retinal blood vessels
 Absorption by blood
vessels
 Foveal area
 Absorption by luteal
pigment
 Parafoveal area
 Mildly decreased
intensity due to high
melanin content and
lower density of
lipofuscin granules in
central RPE

15. In disease state
 Excessive accumulation of lipofuscin in
the lysosomal compartment of the RPE
is the downstream process in many
hereditary and age related diseases

17. AF and ARMD- Basic
Considerations
 RPE is thought to play a key role in the
early and late phases of the disease
 Hallmark of aging is the accumulation of
lipofuscin granules in the cytoplasm of
the RPE cells
 Lipofuscin accumulation is the common
downstream process

18.  Ability to document spatial distribution of
lipofuscin and its changes over time.
 The amount of autofluorescence is signature for
previous or possible future oxidative injury
Hyperfluorescence in FAF FA 36 sec FA 69 sec

19. Geographic Atrophy
 Seen as hypo-
autofluorescent areas
 No RPE, NO
LIPOFUSCIN  NO
AUTOFLUORESCENCE
 Measure the atrophic
area to see for the
progression

20. Geographic atrophy
 Identification of peri-lesional abnormalities
 Hyperautofl signals bordering  denote sick
RPE
 The damage marches in areas of high signals
 Predictor of future trouble

21. Pigment Epithelial Detachment
 Serous PED:
 Increased FAF signal
corresponding to area of
detachmet
 Underlying CNVM: No
specific findings
 Surrounding area: Hypo AF
signal

22. Choroidal
neovascularization
 Irregular FAF in areas of CNV
 High FAF outside the edge of the
lesion
 FAF intensity decreased over the
disciform scars
 In early stages, preservation of
FAF
 Extent of abnormal areas on FAF
is more than that on FA

23. CNVM
CLASSIC FA

24. CSR
 Leaks at the level of RPE
leading to central serous
detachment
 Chronic disease associated
with atrophic changes at the
level of RPE and retina
 FA and ICG – hemodynamics
and fluid dynamics
 OCT- clues to size and
elevation of detachment
 Autofluorescence- functional
status

25. CSR

26. Bull’s eye maculopathy

27. Macular dystrophies-
Stargradt’s disease
 Areas of atrophy on fundus
corresponded to hypo-
autofluorescence
 Flecks seen as
depigmented lesion
appeared as areas of hypo-
autofl
 Predictive value is yet to be
determined

28. Macular dystrophies: Best’s
disease
 Autofl characters: central round
area of increased FAF
 Pseudohypopyon stage:
increased FAF in the lower part
 Late stages: irregular FAF
within the lesion with
disseminated spots of
increased FAF

29. Macular dystrophies: Best’s
disease
 Pattern of spread on FAF: centrifugal
 Atrophic regions are associated with low
levels of background FAF, lower visual
acuity, abnormal colour vision, central
scotomas and poorer
electrophysiological results
 FAF appears more striking and
widespread
 Spoke like, diffuse or combination

30. X-linked retinoschisis
 FAF finding reflect typical radiating
cystic changes
 The changes on FAF are most likely due
to altered passage of exciting and
emitted light from the retinal folds

31. Retinitis Pigmentosa
 In dominant and recessive
and rod-cone dystrophies
 Absent FAF in areas of outer
retinal atrophy
 Normal FAF in adjacent
regions of surviving retina
 High FAF in surviving areas in
some cases
 Macular oedema of more than
4 months  high FAF

32. Retinitis Pigmentosa
 Parafoveal ring of increased FAF
 Correlation exists between these areas
of high FAF and photopic and scotopic
sensitivity

33. Serpigenous Choroiditis
 In SC: Autofluorescence is
detected within 2-5 days
after the appearance of
lesion
 Provides a clear
delineation of the area of
RPE damage
 Progressive decrease in
autofluorescence was seen
during the scarring phase

34. APMPPE
 Affected RPE
demonstrate
increase AF in
early phase of the
disease
 More pronounced
after 3 wks
 Fade away after 1
yr.

35. Macular Hole
 Bright fluorescence of macular holes
similar to images on FA
 Pseudoholes: no such high
autofluorescence
 Attached operculum shows focal
decreased autofluorescence

36. Macular hole surgery

37. VKH
 Hypo AF in the areas of serous
detachments
 NIR AF: hyper AF at the macula and
hypo AF in the areas of serous
detachment
 With treatment: BL-FAF: subtle FAF
 NIR FAF: more wide spread FAF

38. LASER & AF
1 hour 3 hour 3 month

39. Applications for therapeutic
interventions
 In advanced atrophic AMD: useful to
develop and assess the therapeutic
interventions
 Fenritidine, an oral medicine shown to
reduce the production of toxic fluophores
 In retinal dystrophies: useful to assess
the functional preservation of the outer
retina
 In Leber’s: normal or slightly reduced FAF

40. RPE FAF & therapeutic
outcome
 The RPE-FAF of exudative AMD lesions varies
greatly.
 FAF differences have a great influence on the
chances of antivascular endothelial growth factor
(VEGF) therapy success.
 Development of visual acuity is less favorable in
eyes with initially increased central FAF.
Heimes et al. - Foveal RPE FAF as a prognostic factor for anti-VEGF therapy in exudative AMD - GraefesArch 2008

41. CONCLUSION
 Non invasive ,Easy to perform
 Provides a novel prognostic marker for
disease progression
 Metabolic changes and loss of RPE
integrity corresponds to visual function
 In combination with SD OCT it adds to
our understanding of retinal diseases
from a broad point of view.

42. THANK YOU