A nice concise ppt on OCT and OCTA

1. ABC of OCT and OCTA
Ajit K Thakur
M. Optom
Drishti Eye Care System

2. Financial Disclosure : No any financial interest

3. Content
• Background
• Brief History and Time line of Development
• Principle & Instrumentation
• Different brands and their comparison
• Doing OCT and OCTA (Practitioner)
• Reading OCT and OCTA report
• Clinical Pictures

4. Sign Convention
• Outer Retina
• Inner Retina
• Pole
• Equator
• Temporal
• Nasal
• Superior
• Inferior
• Preretinal
• Subretinal
• Choroidal

5. Background
• Optical coherence tomography (OCT)
• In vivo optical biopsy
• Used for biometric purpose
• Optic Coherence Tomography Angiography (OCTA)
• Non-invasive retinal and Choroidal angiography by the analysis of differences in
OCT signals caused by blood flow.

6. History of Development
• David Huang (1991)
• Swanson et al. 1993
IOVS j Special Issue j Vol. 57 j No. 9 j OCT5.

7. Indian J Ophthalmol 2018;66:20-35.
Time Line

8. IOVS j Special Issue j Vol. 57 j No. 9 j OCT12

9. Principle Of OCT and Variants
Optical Coherence Tomography, 1991

10. SD OCT and SS OCT
Ebook: High Resolution Imaging in Microscopy and Ophthalmology: New Frontiers in Biomedical Optics

11. Comparison
TD OCT SD OCT SS OCT
Scanning Speed low high Very high
Resolution low high Very high
Penetration
low high Very high
Image quality Poor Good Better
Artifact Removal
Technology
poor Good Better
Registration Poor Good Better

12. Indian J Ophthalmol 2018;66:20-35.

13. Indian J Ophthalmol 2018;66:20-35.

14. Principle of OCTA
• Based on ultra-high speed sequential acquisition of B-scans of the
exact same retinal area.
• Since OCT-A is based on the principle of multiple scans on the same
retinal location, it requires high speed image acquisition processes
• Decorrelation Algorithm?
• Flow of red blood cells in a vascular network
• Analyze the difference in the reflected OCT signal between static and non-
static tissue from one scan to another

15. Benefits and Limitations of OCTA
• Benefits
• Non invasive with no contraindication
• can evaluate deeper capillary structures, providing a more precise location and
depth of a pathology
• Better to vascular structure below pool or leakage
• Limitation
• a limited field of view
• The inability to depict vessel leakage is another issue
• Artifacts that may lead to misinterpretation
• Low signal strength is another limitation for OCT-A

16. Artifacts
• Motion Artifact
• SSADA/OMAG/Phase Variance
• Motion correction technology
• Projection or Tailing Artifact
• Segmentation artifacts

17. Segmentation Artifact

18. Different Brands
Angioplex
OCT Microangioraphy
complex
Triton Plus
Swept Source (OCTARA)

19. Avanti (Optovue)
SSADA
Spectralis
Multimodal Imaging
Different Brands

20. Angiovue DRI OCT-1
Model Triton
(plus)
Spectralis Cirrus 6000
Scanning Speed
(Acan/Second)
70,000 100,000 85000 100,000
Optical Axial
Resolution
(Micron)
5 8 3.9 5
Optical Transverse
Resolution
(Micron)
15 20 5.7 15
Scan Protocol 3x3, 6x6, 8x8, 4.5 x
4.5, 12x9
12x9mm, 7x7mm,
3x3mm
3x3, 6x6 8x8,
12x12, 4.5x4.5
Angiography SSADA Swept Source
(OCTARA
algorithm)
Amplitude decor
relation algorithm/
Multimodal
Imaging
OMAG
Feature Comparison of Brands

21. Comparison of OCT/OCTA System
PLOS ONE | https://doi.org/10.1371/journal.pone.0177059 May 10, 2017

22. Imaging Technique
• OCT & OCTA
• Scan protocol and their uses
Picture: Angiovue

23. Focus
Picture: Angiovue

24. Scan Protocol & Their Application
Line Scan Report
Cross Line Scan Report
Picture: Angiovue

25. Grid Scan Report
Scan Protocol & Their Application
Raster Lines
Picture: Angiovue

26. Scan Protocol & Their Application
Radial Lines Report
Enhanced HD line report
Picture: Angiovue

27. Scan Protocol & Their Application
Wide Field with en face imaging
Picture: Angiovue

28. Interpretation of An OCT report
• General
• Age, Gender
• Assess the quality of the scan
Ophthalmology 2006; 113: 985-991.

29. Optic Disc: Poor Quality of Scan
TNOA Journal of Ophthalmic Science and Research ¦ Volume 57 ¦ Issue 1 ¦ January-March 2019 37
Segmentation Error
Very Poor Signal
Strength

30. Optic Disc: Poor Quality of Scan
TNOA Journal of Ophthalmic Science and Research ¦ Volume 57 ¦ Issue 1 ¦ January-March 2019 37

31. Optic Disc: Poor Quality of Scan
TNOA Journal of Ophthalmic Science and Research ¦ Volume 57 ¦ Issue 1 ¦ January-March 2019 37

32. Optic Disc
Picture: Angiovue

33. OCT and Glaucoma
TNOA Journal of Ophthalmic Science and Research ¦ Volume 57 ¦ Issue 1 ¦ January-March 2019

34. OCT based Anatomy of Macula
OCT Interpretation in Retinal Disease Executive Clinical Director –ppt of Retina and Macula Specialists Jay M.
Haynie, OD, FAAO

35. Land Marks for OCT interpretation
OCT Interpretation in Retinal Disease Executive Clinical Director –ppt of Retina and Macula Specialists Jay M. Haynie, OD, FAAO

36. Land Marks for OCT interpretation
OCT Interpretation in Retinal Disease Executive Clinical Director –ppt of Retina and Macula Specialists Jay M.
Haynie, OD, FAAO

37. OCT Report
Picture: Angiovue

38. OCT Report : Change Analysis Report
Picture: Angiovue

39. OCTA Report
Picture: Angiovue

40. • Differentiate Inner or Outer Retinal
Disease
• Inner Retina
• DR, HT Retinopathy, Other Vascular Cause
• Outer Retina
• Photoreceptors
• Disease of RPE
• AMD, CSR and Dystrophic Changes
Interpretation of OCT/OCTA
Picture: Angiovue

41. Interpretation of OCT/OCTA
• Qunatative Analysis
• Qulitaive Analysis
• IRMA Vs NV
Indian J Ophthalmol 2018;66:20-35.

42. Clinical Pictures

43. Choroidal Thickness
Picture: Angiovue

44. Case 1
Picture: Angiovue

45. Case 1
Picture: Angiovue
Mac Tel

46. Case 2
Picture: Angiovue

47. Case 2
Picture: Angiovue

48. Picture: Angiovue
CSR

49. Case 3

50. Case 3
Picture: Angiovue

51. Case 3
Picture: Angiovue CNVM?

52. Case 4
Picture: Angiovue BRVO

53. Case 5
Picture: Angiovue

54. Case 5
Picture: Angiovue
NPDR with CNP
areas

55. Case 6
Picture: Angiovue

56. Case 6
Picture: Angiovue
CNVM (?PCV)

57. Case 7
Picture: Angiovue
VMT

58. OCTA: Glaucoma
Picture: Angiovue

59. • 6 specific
• Quality of the images
• Presence of avascular areas within the lesion
• Heterogeneity of the choroidal plexus over the lesion
• Presence of a neovascular membrane associated with the lesion
• Definition of the lesion’s borders
• Presence of a hyperreflective ring surrounding the lesion.
OCTA & Retinal Tumors
Clinical Ophthalmology 2018:12 207–214

60. 1
2
Clinical Ophthalmology 2018:12 207–214

61. 1. Choroidal Nevus
1. Choroidal Melanoma
Clinical Ophthalmology 2018:12 207–214

62. Choroidal Haemangioma
Indian J Ophthalmol 2017;65:1240-2.

63. Indian J Ophthalmol 2017;65:1240-2.
Choroidal Haemangioma

64. Hyperreflective retinal spots
New Landmarks, Signs, and Findings in Optical Coherence Tomography
DOI: http://dx.doi.org/10.5772/intechopen.84242
Posterior Uveitis

65. Clinical Application of OCT in Ophthalmology
IOVS j November 2018 j Vol. 59 j No. 13
DRIL: Disorganization of inner retinal Layer

66. Retinal dystrophies

67. Some OCT/OCTA study from Nepal

68. OCTA Research Article

69. Summary
• OCT and OCTA
• Vital Tool in Ophthalmology these days
• Inquire a lot to acquire a lot
• Use of OCT Angio and OCT in research Field
• Normative data for patients : Research Questions
• Effect of Treatment
• GCC and Blood vessels data linked to systemic condition and can be used as
biomarker for other systemic conditions.
• Research opportunities

70. Please give your Feedback
https://www.surveymonkey.com/r/F8GZ2KC
Contact Details
Email: ajitthakur.drishti@gmail.com
Phone: 00977-9801409740 (Whatsapp/Viber)