Optical Coherence Tomography in Diabetic Retinopathy. Mrs Samantha Mann Consultant Ophthalmologist Clinical Lead of SEL-DESP

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1 Optical Coherence Tomography in Diabetic Retinopathy Mrs Samantha Mann Consultant Ophthalmologist Clinical Lead of SEL-DESP

2 Content OCT imaging Retinal layers OCT features in Diabetes Some NON DR features seen in diabetes patients OCT grading in Diabetes Quiz

Non-contact imaging technique that employs lowcoherence interferometry (light waves analogous to ultrasound waves).

3 Introduction Optical Coherence Tomography (OCT) was first introduced by Huang and colleagues in 1991 and became commercially available in Non-contact imaging technique that employs lowcoherence interferometry (light waves analogous to ultrasound waves). Tissue is segmented into layers based upon reflectance. Algorithm can assign thickness values to each layer Cross-sectional images are constructed from a series of laterally adjacent depth-scans obtained while scanning the probe beam across the eye 3

4 Schematic of Spectral/Fourier Domain OCT super luminescent diode Signal processing Spectrometer + camera 4

5 Developments in OCT Type of OCT Time domain Fourier domain Swept source Spatially encoded frequency domain (SEFD-OCT) Time encoded frequency domain (TEFD- OCT ) A scans/sec , ,000 Resolution 16 m 10 m 5 m 3 m spectrometer based system frequency swept laser based system 5

6 Time domain Fourier domain UH-SD (3 m) Swept source CSI 6

7 Retinal Structure / OCT layers

8 Normal Retinal OCT/ false colour 8

9 Staurenghi G et al. Ophthalmology 2014;121:

11 Retinal Layers Pre-retinal Retinal Subretinal/ choroidal

12 Trilaminar band IS/OS junction Interdigitation zone RPE

13 Relative OCT Signal Reflectivity SIGNAL High (white) Moderately High Moderate (grey) Moderately Low Low (black) STRUCTURES RPE, IS/OS junction, exudate, ERM NFL, Scar Tissue, CNV, blood, vitreo-retinal interface Retina, Choroid, Vitreous bands Vitreous debris, Posterior hyaloid, Outer retina, noise Vitreous, Silicone oil, Cysts, Shadowing behind blood vessels and behind exudates 13

14 Vitreous/ vitreoretinal interface Diabetes feature Vitreous haemorrhage Vitreo-macular traction Non DR patholoy Vitreous haemorrhage (secondary to PVD/retinal tear) Vitreo-macular traction/ Epi-retinal membrane Posterior hyaloid Pre-retinal haemorrhage Valsalva haemorrhage NVD/NVE Retinal Microaneurysms/ exudates Lamellar hole/ macular hole/ Retinal Vein Occlusion Cotton wool spot (NFL) Intra-retinal cysts/ DMO CRAO Cystoid macular oedema secondary to RVO/post op Sub-Retinal Subretinal fluid Central serous retinopathy/ AMD sub RPE/ Choroidal/ Bruchs PED, CNV, wet AMD, polypoidal, drusen, Geographic atrophy 14

15 Vitreous Haemorrhage Often no signal or minimal signal with vitreous haemorrhage

16 Epiretinal Membrane (non DR) traction

17 Vitreo-Macular Traction (non DR)

18 Vitreo-Macular Traction- requires VR referral

19 Pre-retinal Haemorrhage Pre-retinal haem exudates

20 New Vessels Elsewhere

21 New Vessels at Disc

22 Traction retinal detachment- requires VR referral

23 Exudates/ microaneurysms Exudates Exudates

24 Cotton Wool Spots

25 Diabetic Macular Odema (DMO) Hyperreflective dots Intra-retinal cysts Exudates

26 Diabetic Macular Odema (DMO) Intraretinal cysts Subretinal fluid

27 DRIL

28 DRIL associated with worsening VA

29 Disorganisation of the Retinal Inner Layers 1mm

30 Centre-involving Clinically Significant Diabetic Macular Oedema Retinal thickening Improved Post 4 anti- VEGF injections

31 Branch Retinal Vein Occlusion- non DR Retinal flame haemorrhages Macular oedema

32 Central Retinal Vein Occlusion- non DR Cystoid macular oedema

33 Branch Retinal artery Occlusion- non DR Retinal thinning

34 Laser Scars Laser scars in RPE/ photoreceptors

35 Macular drusen Drusen deposits in Bruch s membrane

36 Wet Age-related Macular Degeneration Subretinal fluid Sub-retinal haemorrhage Choroidal neovascularisation

37 OCT pathway for M1 s All R1M1 from screening or stabler3(s)m1 DIRECT TO HES On digital photography there is substantial macular exudation (>1/2 Disc area within 1 DD of fovea) AND a significant drop in visual acuity (>2 lines or worse than 6/12 OCT clinic OCT negative Back to Screening OCT borderline Stay in OCT OCT positive Stay in Oct or refer to HES* * According to local protocol

38 Direct to HES (>1/2 DA & VA 6/12 or worse) 6/12 6/6 6/12 6/9

39 Definitions OCT grade OCT negative OCT borderline OCT positive Diabetes Non DR No intra-retinal cysts or subretinal fluid or solitary intraretinal lesion AND NO change in ILM contour BACK to SCREENING Presence of intra-retinal cysts or solitary intraretinal lesions (due to diabetes) AND NO change in ILM contour STAY IN SURVEILLANCE 1) Presence of intraretinal cysts or intraretinal lesions (due to diabetes) AND with a change in ILM contour 2) Parafoveal thickening of greater than 0.5 disc area 3) Area of thickening >1.0 disc area within the macula region 4) Any R3A REFER TO HES/STAY IN SURVEILLANCE* (local protocol) Wet AMD, Drusen, VMT, CRVO, BRVO

40 OCT positive -3 definitions (1) An area of retinal thickening of greater than 1/2 disc area the edge of which is within 1 disc diameter of the central fovea (2) An area of retinal thickening of greater than 1.0 disc area within the NHS DESP definition of the macula (3)Any cystic change or single lesion in the retina from diabetes resulting in a change of the foveal ILM contour

41 Severe Diabetic Macular oedema >400 microns central macular thickness Fast track to Med Ret CLINIC For Anti-VEGF injection Therapy 135 degrees 90 degrees 45 degrees

42 Case 1) OCT negative- Back to Screening

43 Case 2) OCT borderline- stay in OCT surveillance

44 Case 3) OCT borderline- stay in surveillance

45 Case 4) OCT positive (>1/2 DA within 1DD of fovea) Refer to HES or stay in surveillance

46 Case 5) OCT positive (loss of ILM contour)

47 Case 6) OCT positive (>1DA in macular area) Refer to HES

48 Case 7) OCT positive with significant thickening & pre-retinal haem Intra-retinal cyst exudates Refer to HES

49 QUIZ

50 CASE A

51 CASE A- OCT borderline (<1DA in macula)

52 CASE B

53 CASE B- OCT negative

54 CASE C exudates

55 CASE C- OCT borderline (exudates present) no change in ILM contour exudates

56 CASE D

57 CASE D- NVE Urgent R3A referral

58 CASE E

59 CASE E- OCT positive (>1DA in macula)

60 CASE F

61 CASE F- OCT Positive (Fast Track to Clinic >400 microns thickness)

62 CASE G

63 CASE G? OCT Borderline- no change in contour BUT..

64 CASE G Always look at the Map view >1DA thickening within the Macular Area OCT positive

65 Thank you

The Quick Guide to OCT Mastery 50 Real Cases with Expert Analysis

OPTICAL COHERENCE TOMOGRAPHY The Quick Guide to OCT Mastery 50 Real Cases with Expert Analysis VOL 1 Sanjay Sharma, MD, FRCS, MSc (Epid), MBA Ophthalmologist, Epidemiologist Queen s University, Canada