NEW INSTRUMENTS/CASE DISCUSSION

1. NEW INSTRUMENTS/CASE DISCUSSION Speaker M Jayasree Moderators J Manju Anju

2. Contents • Optical Coherence Tomography • Microperimetry • Multifocal Electroretinogram • Glaucoma Diagnostics • GDx • HRT • GLAUCOMA OCT • HVF

3. OCULAR COHERENCE TOMOGRAPHY PRINCIPLE • Optical involves light and optics Used for Optical biopsy of retina. • Coherence– two light beams of same wave length in phase. Uses principle of low coherence interferometry. • Tomography Tome/Tomo – Greek for section /cutting

4. SDOCT Resolution – 6 microns Wavelength – 840 nm 3-D imaging No movement artifacts 25,000 A-scans/second Determining and visualizing structure that absorb and scatter light Noncontact Noninvasive

5. Indications • Retinal- macula and Optic nerve. • Inconclusive FFAs- done together. • Quantify extent of lesions ex-CNVM, thickness of macula. • Quantify RNFL thickness around Optic nerve head.

8. Hypo reflectivity Hyper reflectivity Above the NFL Posterior Hyaloid ,Epiretinal Membrane,Blood In the NFL Inflammation, Cotton Wool Spots, Blood Vessels, Flame Shaped Hemorrhages In the nuclear and plexiform layers Hard Exudates, Dot Blot Hemorrhages In the RPE CC layer Hyperpigmentation, CNV In the sub RPE layer Drusens, Blood, Fibrosis In the choroids Scar, Transmission Absence Edema Cystoid spaces Fluid – serous

9. NORMAL VITREO RETINAL INTERFACE • NORMAL FOVEAL CONTOUR WITH FOVEAL DIP • INNER RETINAL RETINAL LAYERS ARE NORMAL • NORMAL RPE CC COMPLEX • FOVEAL THICKNESS

10. NORMAL VITREO RETINAL INTERFACE • FOVEAL CONTOUR ALTERED • THICKENED HYPERREFLECTIVE INNER LAYERS • E/O SRF , SUGGESTIVE OF ACTIVE CNVM WITH CYSTIC SPACES IN THE INNER RETINAL LAYERS

11. THICK ERM NOTED • ALTERED FOVEAL CONTOUR • LARGE CNVM, NO E/O SRF SUGGESTIVE OF SCARRED CNVM

12. THIN ERM • ELEVATED FOVEAL CONTOUR • THICKENED AND HIGH REFLECTIVE MEMBRANE NOTED SUBFOVEALLY • NO E/O SRF,SUGGESTIVE OF SCARRED CNVM • SMALL DRUSENOID PED

13. WRINKLED ILM • ALTERED FOVEAL CONTOUR • INNER RETINAL LAYERS ARE THICK AND CYSTIC SPACES • THICKENED AND HIGH REFLECTIVE RPE-CC COMPLEX WITH MULTIPLE PED

14. NORMAL VITREO RETINAL INTERFACE • FOVEAL CONTOUR ELEVATED AND THINNED • HYPER REFLECTIVE INNER LAYES • CSR • SEROUS PED

15. NORMAL VITREO RETINAL INTERFACE • FOVEAL CONTOUR ALTERED • HEMORRHAGIC PED

16. WRINLED ILM • FOVEAL CONTOUR ALTERED • CYSTIC SPACES IN THE INNER RETINAL LAYERS • SEROUS AND FIBROUS PED

17. INCOMPLETE POSTERIOR VITREOUS DETACHMENT • FOVEAL CONTOUR ALTERED • FIBROVASCULAR PED

18. INCOMPLETE POSTERIOR VITREOUS DETACHMENT • FOVEAL CONTOUR ALTERED • DRUSENOID PED

19. NORMAL VITREO RETINAL INTERFACE • FOVEAL CONTOUR ALTERED • HARD EXUDATES IN THE INNER RETINAL LAYERS • NORMAL RPE CC COMPLEX

20. NORMAL VITREO RETINAL INTERFACE • FOVEAL CONTOUR ALTERED • DIFFUSE HARD EXUDATES IN THE INNER RETINAL LAYERS • NORMAL RPE CC COMPLEX

21. NORMAL VITREO RETINAL INTERFACE • CSME CME FOVEOLAR DETACHMENT • THICKENED HYPER REFLECTIVE CYSTIC SPACED INNER LAYERS • NORMAL RPE-CC COMPLEX

22. NORMAL VITREO RETNAL INTERFACE • FOVEAL CONTOUR ELEVATED/THINNING • NEURO SENSORY DETACHMENT • SRF, SUGGESTIVE OF CSR • NORMAL RPE COMPLEX

23. ERM WITH ILM FOLDS • FOVEAL CONTOUR ALTERED • INNER RETINAL THICKENED • NORMAL RPE CC COMPLEX

24. ERM WITH WRINKLING ILM • LAMELLAR MACULAR HOLE • THIN INNER RETINAL LAYERS • NORMAL RPE COMPLEX

25. FULL THICKNESS MACULAR HOLE WITH OPERCULUM

26. COMPLETE POSTERIOR VITREOUS DETACHMENT • VITREOUS TRACTION RELEASED

27. NORMAL VITREO RETINAL INTERFACE • FOVEAL SCHISIS • THINNED CYTIC SPACES INNER LAYERS • RPE ALTERED

28. FOVEAL CONTOUR ALTERED • OPTIC DISC PIT

29. OPTIC DISC PIT MACULOPATHY

30. VITREO MACULAR TRACTION

31. Case 1 PRE TREATMENT • DATE OF VISIT 22/08/08 • BCVA OS 6/36, N36 • SL OS WNL • FUNDUS OS CNVM, SUB RETINAL HEAMORRHAGE • OCT OS E/O SRF , SUGGESTIVE OF ACTIVE CNVM WITH CYSTIC SPACES IN THE INNER RETINAL LAYERS OS INJ AVASTIN GIVEN THRICE POST TREATMENT • DATE OF VISIT 22/11/08 • BCVA OS 6/12, N8 • SL OS WNL • FUNDUS OS SCARREDCNVM, • OCT OS NO E/O SRF , SUGGESTIVE OF SCARRED CNVM WITH CYSTIC SPACES IN THE INNER RETINAL LAYERS

32. PROGNOSIS HOLE FORM FACTOR • HFF > 0.9 - 100 % PRIMARY CLOSURE • HFF = 0.5 - 67 % PRIMARY CLOSURE • HFF < 0.5 - Poor closure rates • HIGHER HFF - BETTER POST OP VA

33. CASE 2 PRE TREATMENT • DATE OF VISIT (25/09/08) • BCVA OS 6/48(ECC VIEW), N24 • S/L OS NO ABNORMALITY • FUNDUS OS FTMH • OCT OS FULL THICKNESS MACULAR HOLE WITH COMPLETE PVD POST TREATMENT S/P VIT+C3F8 UNDER GA • DATE OF VISIT (6/12/08) • BCVA OS 6/12+, N8 • S/L OS WNL • FUNDUS OS • OCT OS

34. Multifocal Electroretinogram (mfERG) in Retinal Disorders

35. Multifocal electroretinogram • Simultaneous recording of focal retinal responses • Offers direct, objective and topographical mapping of central 36-40º of retinal function • Cone driven responses • Fovea, Para fovea and near peripheral photopic retina function can be evaluated.

36. mfERG Stimulus • Display contains array of hexagons- • Commonly used 103 hexagonal array • Scaling basis - Photoreceptor density • Produce local retinal responses of equal amplitude • Flickers according to pseudorandom binary m-sequence

37. 1.6° 1.6°- 6° 6°-11.4° 11.4°-18.2° 18.2°-26.2° • 26.2°-35° • Waveforms grouping according to different retinal eccentricities • Subtends 35° horizontally and 31° vertically – viewing distance 53cm • The responses obtained from six zones

38. First order kernel responses- Interpretation Multiplot Trace Array

39. mfERG Components Parameters • N1 – First negative trough • P1- First positive Peak • Origins • Cone Photoreceptors • Dominated by on and off bipolar cells P1-IT P1- AMP N1- IT N1-AMP

40. Interpretation • Degenerative photoreceptor disease • Larger delay in implicit times • Local lesions damaging INL • Larger reduction in amplitudes • Damage to NFL or GCL • No reduction or delay

41. Clinical applications • To distinguish retinal diseases from optic nerve disease • Details extent of lesion • Sensitive indicator for retinal drug toxicity • Post-operative management following V-R surgery • Assess sub-clinical retinal changes in DR

42. Case 1 Stargardt’s disease Few yellowish flecks at the macula

43. FullfieldERG

44. Multifocal ERG – Trace array

45. Multiplot Crater like defect - MfERG delineates the macular pathology

46. Case 2 Cone Dystrophy

47. FullfieldERG

48. Multifocal ERG – Trace array

49. Multiplot

50. Case 3