Spectralis oct normal anatomy & systematic interpretation.
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Transcript of Spectralis oct normal anatomy & systematic interpretation.
Interpretation and Terminology
of OCT for Retina
Christopher Mody Clinical
Programme Manager
Heidelberg Engineering Ltd
Make valued judgements whilst scanning
Utilise the fundus reference image
Understand the significance OCT image
Identify pathology & link to visual
symptoms
30° high resolution line scan
Fovea
Inf
Dark regions :
• Intra retinal fluid
• Sub retinal fluid
• Sub RPE fluid
• Retinal elevation
IR fundus reference image
Green areas :
• Intra retinal fluid
• Sub retinal fluid
• Sub RPE fluid
• Retinal elevation
MultiColor fundus reference image
Blue laser FAF reference image
Dark regions:
• Retinal atrophy
• RPE atrophy
Bright regions:
• Active disease
Normal OCT
What does the SD-OCT image actually
represent?
N T
Fovea
Internal Limiting Membrane
Retinal Blood Vessels
RNFL
Ganglion Cell Layer
Inner Plexiform Layer
Inner Nuclear Layer
Outer Plexiform Layer
Outer Nuclear Layer
External Limiting Membrane
Henle fibre layer
Choroid
Inner photoreceptor segments
Inner/outer photoreceptor junction
Rod/cone outer segments
RPE interdigitation
Bruch’s/RPE Complex
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
Rods & Cones
OS EZ
MZ
ELM
ONL
OPL
IZ
RPE
Inner segment
Ellipsoid zone
Mitochondria
ATP production – chemical energy
Myoid zone
Golgi apparatus
Protein synthesis
Ellipsoid zone
Myoid zone
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
STEP 1
Determine overall scan quality
Scan quality
Qualitative assessment
Qualitative assessment
Step 1
Scan quality
Identify inner and outer retinal band
Good signal to noise ratio
Truncated
Shadowing
Vitreous opacities
Vessel shadowing
STEP 2
Rate the overall scan profile
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.
The over-all retinal profile
RPE detachment
Fibrotic/Serous
Haemorrhagic
Retinal detachment
Rhegmatogenous
Serous
Retinal thickening
CSMO/CMO/CNV
STEP 3
Evaluate the foveal profile
Qualitative assessment
Step 3. Evaluate the foveal profile
The normal foveal profile is a slight
depression in the surface of the retina.
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)
STEP 4
Identify foveal cut
Fovea Do you have a foveal cut?
STEP 5
Carry out a structural assessment
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
Qualitative assessment
Pre-retinal
Epiretintal
Intra-retinal
Sub-retinal • Sub neurosensory retina
• Sub RPE
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
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
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
Qualitative assessment
Sub-retinal/RPE:
1. choroidal neovascularization
2. RPE detachment
3. Drusen
4. sub-retinal fibrosis
5. scar tissue
6. RPE atrophy
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
TERMINOLOGY
Irregularity
Fragmentation
Rupture
Interruption
Depression
Elevation
Thinning
Thickening
Alteration of Layers
Terminology
Irregularity
Fragmentation
Rupture
Interruption
Depression
Elevation
Thinning
Thickening
RPE
Terminology
Irregularity
Fragmentation
Rupture
Interruption
Depression
Elevation
Thinning
Thickening
RPE
Terminology
Irregularity
Fragmentation
Rupture
Interruption
Depression
Elevation
Thinning
Thickening
RPE
Terminology
Irregularity
Fragmentation
Rupture
Interruption
Depression
Elevation
Thinning
Thickening
RPE
Terminology
Irregularity
Fragmentation
Rupture
Interruption
Depression
Elevation
Thinning
Thickening
RPE
Terminology
Irregularity
Fragmentation
Rupture
Interruption
Depression
Elevation
Thinning
Thickening
RPE
Terminology
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
Identify RPE Examine
RPE
Examine posterior to
RPE
Examine anterior to
RPE
Systematic Procedure
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
Identify RPE Systematic Procedure
Examine RPE
One single elevation of RPE (PED)
Undulating (wavy) PED
No interruption
No thickening or thinning of RPE
Identify EPR
Identify RPE Examine
RPE
Examine posterior to
RPE
Sub-RPE Reflectivity moderate
Shadow at RPE / sub - RPE
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)
Posteriorto RPE
Examine anterior to
RPE
Intra & subretinal fluid
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
Questions…
Acknowledgements:
Evangelos Tsiroukis MD
Institut Català de Retina
Barcelona
Professor Yit Yang
Wolverhampton Eye
Infirmary