Spectralis oct normal anatomy & systematic interpretation.

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Heidelberg Lecture on anatomical structures visable on a OCT scan

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Spectralis oct normal anatomy & systematic interpretation.

  1. 1. Interpretation and Terminology of OCT for Retina Christopher Mody Clinical Programme Manager Heidelberg Engineering Ltd
  2. 2.  Make valued judgements whilst scanning  Utilise the fundus reference image  Understand the significance OCT image  Identify pathology & link to visual symptoms
  3. 3. 30° high resolution line scan Fovea Inf
  4. 4. Dark regions : • Intra retinal fluid • Sub retinal fluid • Sub RPE fluid • Retinal elevation IR fundus reference image
  5. 5. Green areas : • Intra retinal fluid • Sub retinal fluid • Sub RPE fluid • Retinal elevation MultiColor fundus reference image
  6. 6. Blue laser FAF reference image Dark regions: • Retinal atrophy • RPE atrophy Bright regions: • Active disease
  7. 7. Normal OCT
  8. 8.  What does the SD-OCT image actually represent?
  9. 9. N T Fovea Internal Limiting Membrane Retinal Blood Vessels
  10. 10. RNFL Ganglion Cell Layer Inner Plexiform Layer Inner Nuclear Layer Outer Plexiform Layer Outer Nuclear Layer External Limiting Membrane
  11. 11. Henle fibre layer
  12. 12. Choroid Inner photoreceptor segments Inner/outer photoreceptor junction Rod/cone outer segments RPE interdigitation Bruch’s/RPE Complex
  13. 13. Pre-Euretina Normal OCT Classification Formed Vitreous Posterior Cortical Vitreous Preretinal Space Nerve Fiber Layer Ganglion Cell Layer Inner Plexiform Layer Inner Nuclear Layer Outer Plexiform Layer (dendritic) Henle’s-ONL junction (subtle) Henle Fiber Layer (axonal OPL) Outer Nuclear Layer Sattler’s Layer (inner Choroid) Haller’s Layer (Outer Choroid) External Limiting Membrane Ellipsoid Zone Outer Segments Interdigitation Zone Choriocapillaris RPE/ Bruch’s Complex Myoid Zone Choroid Sclera Junction
  14. 14. Rods & Cones OS EZ MZ ELM ONL OPL IZ RPE
  15. 15. Inner segment  Ellipsoid zone  Mitochondria  ATP production – chemical energy  Myoid zone  Golgi apparatus  Protein synthesis Ellipsoid zone Myoid zone
  16. 16. Evaluating OCT images 1. Determine scan quality 2. Rate overall scan profile 3. Evaluate foveal profile 4. Identify foveal cut 5. Carry out structured assessment  Observe alteration of layers  Identify additional structures  Pre retinal  Epiretinal  Intraretinal  Subretinal  Sub RPE
  17. 17. STEP 1 Determine overall scan quality
  18. 18.  Scan quality Qualitative assessment
  19. 19. Qualitative assessment Step 1  Scan quality  Identify inner and outer retinal band  Good signal to noise ratio  Truncated  Shadowing
  20. 20. Vitreous opacities
  21. 21. Vessel shadowing
  22. 22. STEP 2 Rate the overall scan profile
  23. 23. Qualitative assessment Step 2. Rate the over-all retinal scan profile  The normal over-all retinal profile has a slightly concave curvature.  Abnormal profiles would include exaggerated concavity and convexity or retinal folds.
  24. 24. The over-all retinal profile  RPE detachment  Fibrotic/Serous  Haemorrhagic  Retinal detachment  Rhegmatogenous  Serous  Retinal thickening  CSMO/CMO/CNV
  25. 25. STEP 3 Evaluate the foveal profile
  26. 26. Qualitative assessment  Step 3. Evaluate the foveal profile  The normal foveal profile is a slight depression in the surface of the retina.
  27. 27. Foveal profile  Deformations in the foveal profile include the following: 1. Macular pucker 2. Macular pseudo-hole 3. Macular lamellar hole 4. Macular cyst 5. Macular hole, stage 1 (no depression, cyst present) 6. Macular hole, stage 2 (partial rupture of retina, increased thickness) 7. Macular hole, stage 3 (hole extends to RPE, increased thickness, some fluid) 8. Macular hole, stage 4 (complete hole, oedema at margins, complete PVD)
  28. 28. STEP 4 Identify foveal cut
  29. 29. Fovea Do you have a foveal cut?
  30. 30. STEP 5 Carry out a structural assessment
  31. 31. Qualitative Assessment Step 5. Carry out a structural assessment a) Observe alteration of layers b) Identify additional structures • Pre-retinal • Epiretinal • Intra-retinal • Sub-retinal • Sub RPE
  32. 32. Qualitative assessment Pre-retinal Epiretintal Intra-retinal Sub-retinal • Sub neurosensory retina • Sub RPE
  33. 33. Qualitative assessment  Pre retinal – vitreous cavity: 1. pre-retinal membrane 2. epi-retinal membrane 3. vitreo-retinal strands 4. vitreo-retinal traction 5. syneresis 6. pre-retinal neovascular membrane NVE 7. pre-papillary neovascular membrane NVD
  34. 34. Qualitative assessment  Pre-retinal  A normal pre-retinal profile is displayed as a black or white space.  Prepapilla/prefoveal lacunae (premacula bursa) may be visible
  35. 35. Qualitative assessment  Intra-retinal changes: 1. Choroidal neovascularization 2. Diffuse intra-retinal oedema 3. Cystoid macular oedema 4. Hard exudates 5. Scar tissue 6. Atrophic degeneration
  36. 36. Qualitative assessment  Sub-retinal/RPE: 1. choroidal neovascularization 2. RPE detachment 3. Drusen 4. sub-retinal fibrosis 5. scar tissue 6. RPE atrophy
  37. 37. What to look for… 1. Determine scan quality 2. Rate overall scan profile 3. Evaluate foveal profile 4. Identify foveal cut 5. Carry out structured assessment  Observe alteration of layers  Identify additional structures  Pre retinal  Epiretinal  Intraretinal  Subretinal  Sub RPE
  38. 38. TERMINOLOGY
  39. 39. Irregularity Fragmentation Rupture Interruption Depression Elevation Thinning Thickening Alteration of Layers Terminology
  40. 40. Irregularity Fragmentation Rupture Interruption Depression Elevation Thinning Thickening RPE Terminology
  41. 41. Irregularity Fragmentation Rupture Interruption Depression Elevation Thinning Thickening RPE Terminology
  42. 42. Irregularity Fragmentation Rupture Interruption Depression Elevation Thinning Thickening RPE Terminology
  43. 43. Irregularity Fragmentation Rupture Interruption Depression Elevation Thinning Thickening RPE Terminology
  44. 44. Irregularity Fragmentation Rupture Interruption Depression Elevation Thinning Thickening RPE Terminology
  45. 45. Irregularity Fragmentation Rupture Interruption Depression Elevation Thinning Thickening RPE Terminology
  46. 46. Additional Structures Macular Hole Epiretinal Membrane (ERM) Drusen Blood Component Fluid /Edema Non Exudative Spaces Neovascularisation Fibrosis Lipid Precipitates Hyperreflective Spots & Dense Areas Tubulations of Outer Retina Tumours
  47. 47. Identify RPE Examine RPE Examine posterior to RPE Examine anterior to RPE Systematic Procedure
  48. 48. RPE • Irregularity • Fragmentation • Rupture • Interruption • Depression • Elevation • Thinning • Thickening Posterior to RPE • PED • Bruch’s Membrane • Hyperreflectivity (atrophy of RPE vs. fibrosis) • Hyporeflectivity (screen effect) Anterior to RPE • Vitreous • Retinal Thickness • Foveal Depression • Subretinal Fluid • ELM • Elipsoid Zone • Hyperreflective Spots • Dense Areas • Outer Nuclear Layer • Intraretinal Cysts • Inner Retinal Layers
  49. 49. Identify RPESystematic Procedure
  50. 50. Examine RPE One single elevation of RPE (PED) Undulating (wavy) PED No interruption No thickening or thinning of RPE Identify EPR
  51. 51. Identify RPE Examine RPE Examine posterior to RPE Sub-RPE Reflectivity moderate Shadow at RPE / sub - RPE
  52. 52. Hyperreflective Zone in inner layers Intraretinal Cysts (in 2 layers) Increased retinal thickness Large Hyperreflective Precipitates Hyperreflective Punctiform Precipitates Dense Areas anterior to RPE Interruption of ELM & Elipsoid Zone Identify RPE Examine RPE Retinal Angiomatous Profliferation (RAP) Posterio rto RPE Examine anterior to RPE Intra & subretinal fluid
  53. 53. Final thoughts…  Know your chorio retinal anatomy  Familiarise yourself with normal variation in OCT recordings  Adopt a systematic approach to evaluating OCT images  Familiarise yourself with the aetiology of macular disease  Don’t forget vision, signs/symptoms, history and fundus appearance
  54. 54. Questions… Acknowledgements: Evangelos Tsiroukis MD Institut Català de Retina Barcelona Professor Yit Yang Wolverhampton Eye Infirmary

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