This document provides an overview of macular pathology and OCT interpretation. It discusses various retinal conditions including: - Retinal hemorrhages and their locations (vitreous, pre-retinal, intraretinal, subretinal) - Common findings on OCT including pathology involving different retinal layers (inner retina, outer retina) and features like the photoreceptor integrity line. - Examples of diseases like diabetic retinopathy, retinal vein occlusions, AMD (dry and wet), central serous retinopathy, macular holes, optic disc pits, and retinitis pigmentosa. It emphasizes assessing retinal layers, fluid locations, RPE appearance, and photoreceptor integrity to

1. An u p d ate on m acu lar
p ath ology

2. Talk summary
• Clinical signs
– Retinal haemorrhage and differential diagnosis
– The cotton wool spot
– Exudate vs Drusen
• OCT signs
– Basics of OCT interpretation
– When to refer
– Some rare cases

3. Retinal haemorrhage, what depth?
• Vitreous
• Pre retinal
• Intraretinal (superficial and deep)
• Sub retinal
• Sub RPE
• More than one level

4. Vitreous haemorrhage
• Poor fundal view / poor red reflex
• Pulling on blood vessel
– Retinal tear with PVD or trauma
– Proliferative diabetic retinopathy / BRVO
• “Break through” bleeding
– Severe wet AMD
– Retinal macroaneurysm

5. Pre retinal haemorrhage
(boat shaped)
Haemorrhage limited by extent of vitreous separation
Masks retinal blood vessels

6. Superficial intra retinal haemorrhage
(flame shaped)
Confined by nerve fibre layer, masks retinal blood vessels

7. Deep intra retinal haemorrhage
(dot and blot)
May be in front of or behind the retinal blood vessels

8. Sub retinal haemorrhage
(round)
retinal blood vessels visible
Sub RPE haemorrhage similar but darker

9. The “cotton wool spot”
Think – Hypertension, Diabetes, Smoker
Rarely – HIV retinopathy, SLE
What is this?

10. Exudate vs drusen
If exudate is present there must be signs of leakage from
abnormal blood vessels (micro or macroaneurysms, CNV)

11. Life is not that simple
What is this?

12. Principles of the OCT
• Based on interferometry
– Interference between incident and reflected light
• Like doing a vertical biopsy of the retina
– Use laser light rather than knife!
• Resolution down to 10 microns
• Nerve fibre layer and RPE well defined
• Good at showing swelling due to leakage
• FFA still needed for showing blockage

13. Confusing but important terms
• Inner retina
– Next to vitreous cavity
– Nerve fibre layer
– Interconnecting neurons
• Outer retina
– Next to choroid
– Rods and cones
– RPE

14. Retina pathology often in layers
• Inner retina
– Diabetic retinopathy
– Retinal vein occlusion
• Outer retina
– AMD
– CSR

15. OCT pathology often in layers
• Retinal surface
– Vitreo-macular traction
– Epiretinal membrane
• Inner retina
– Diabetic retinopathy
– Retinal vein occlusion
• Outer retina
– AMD
– CSR

16. Retinal pathology in more than
one layer
• Macular hole
– All layers involved (full thickness)
• Lamellar hole
– Usually surface and inner retina
• Severe retinal disease
– Wet AMD
– Diabetic eye disease
– Retinal vein occlusions

17. Central macular thickness
• Can be difficult to assess function on
thickness alone
• Normal thickness = 200 microns
• Thick retina > 250 microns
– Usually due to leakage
• Thin retina < 150 microns
– Atrophic with poor function

18. The photoreceptor integrity line
• Junction between inner and outer segments
• Barely visible in histological sections
• Highly prominent with OCT
• Due to difference in index of refraction of the
inner and outer segments

19. Assess retinal function
• Thick retina = oedema
• Thin retina = atrophic retina
• Normal thickness retina – how is it functioning?
• Well demarcated IS/OS junction suggest good
photoreceptor function

20. Vitreo-macular traction
• Posterior vitreous pulling on macula
• Wide range of severity
• If incidental OCT finding and patient
asymptomatic – do not refer

21. Severe Vitreo-macular traction
0.5 LogMAR
“Pointed - being Pulled”

22. Mild Vitreo-macular traction
Inner retinal cyst
0.12 LogMAR

23. Epiretinal membrane
• Posterior vitreous usually detached
• Sometimes associated with lamellar hole
• Wide range of severity
• If incidental OCT finding and patient
asymptomatic – do not refer

24. Lamellar macular hole with ERM
Note ERM with “saw tooth sign”
Lamellar macular hole
Note healthy IS / OS junction
Visual acuity is 0.12
No symptoms

25. Mild epiretinal membrane
0.1 LogMAR
Loss of foveal pit

26. Lamellar macular hole with ERM
0.1 LogMAR
Asymptomatic

27. ERM with lamellar hole
No symptoms
-0.1 LogMAR
Good IS / OS junction

28. Basics of diabetic retinopathy
• Retinal blood vessels involved
• Inner retina first involved
• Fluid
– Intra retinal (including cystoid oedema)
– Sub retinal if severe
– No Sub RPE fluid
• Hard exudates
– Highly reflective intraretinal spots
• RPE looks ok

29. Basics of diabetic retinopathy

30. Basics of retinal vein occlusions
• Retinal blood vessels involved
• Inner retina first involved
• Fluid
– Intra retinal (including cystoid oedema)
– Sub retinal if severe
– No Sub RPE fluid
• Hard exudates
– Less frequently seen than in diabetics
• RPE looks ok

31. Basics of retinal vein occlusions

32. Basics of dry AMD
Drusen
“Lumpy bumpy” RPE

33. Basics of dry AMD
RPE atrophy
High signal beneath RPE
Thin retina

34. Basics of Wet AMD
• Blood vessels from choroid
• Outer retina first involved
• Fluid
– Sub RPE
– Sub Retinal
– Intra retinal (includes cystoid oedema)
• Usually previous dry AMD
– Look at RPE line as rarely “pristine”

35. Basics of Wet AMD
Sub RPE fluid Intra retinal fluid
Sub retinal fluid Note previous dry changes

36. “Burnt out” Wet AMD
Scarring and chronic leakage

37. Basics of CSR
• Leakage from choroid
• Fluid
– Sub Retinal
• RPE
– May be small PED associated
– Remaining RPE looks healthy

38. Basics of CSR

39. Full thickness macular hole

40. Spontaneous improvement in a
full thickness macular hole
0.0 LogMAR
0.1 LogMAR

41. Post macular hole op
0.32 LogMAR

42. Ask yourself
• Anything on the surface?
• Is it mainly inner or outer retina or both?
• How does the RPE look?
• How well demarcated is the IS /OS
line?

43. Small BRVO or wet AMD at
macula?
• BRVO
– Inner retina (inner and outer if severe)
– RPE normal
– IS / OS may be preserved
• Wet AMD
– Outer retina (inner and outer if severe)
– RPE abnormal
– IS / OS disrupted

44. Pre and post Ozurdex in macular
oedema from vein occlusion
0.5 LogMAR
0.3 LogMAR

45. Pre and post Ozurdex in diabetic

46. Sept 2011 Feb 2012 April 2012
Ozurdex for CRVO

47. What is this?

48. Adult vitelliform dystrophy

49. Adult vitelliform dystrophy
0.22 LogMAR OS
0.0 LogMAR OD
Intact IS / OS junction

50. What is this and what is the vision?

51. Macula schisis
0.0 LogMAR 0.1 LogMAR
Intact IS / OS junction Intact IS / OS junction

52. What is this?

53. It was due to this !

54. What is this?

55. Optic disc pit maculopathy

56. Retinitis pigmentosa
Pre – Sub Tenon’s steroid Post injection
“Bell shape – from Below” Note thin retina
No IS / OS junction