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. Determining and visualizing structure that absorb and scatter light
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.

7. Normal Retina RNFL - high reflective (red)
IPL & OPL - moderate back scattering(yellow)
Nuclear layers - min.back scattering (green)
Photoreceptors - dark layer
RPE & choriocapillaries - high reflective(red)
Choroid & sclera - low reflectivity

8. Hyper reflectivity Hypo 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 POST TREATMENT
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 > % PRIMARY CLOSURE
HFF = % PRIMARY CLOSURE
HFF < Poor closure rates
HIGHER HFF - BETTER POST OP VA

33. CASE 2 PRE TREATMENT POST TREATMENT S/P VIT+C3F8 UNDER GA
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. Waveforms grouping according to different retinal eccentricities
Subtends 35° horizontally and 31° vertically – viewing distance 53cm
The responses obtained from six zones
1.6 °
1.6°- 6°
6°-11.4°
11.4°-18.2°
18.2°-26.2°
26.2°-35°

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 Larger delay in implicit times
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. Fullfield ERG

44. Multifocal ERG – Trace array

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

46. Case 2
Cone Dystrophy

47. Fullfield ERG

48. Multifocal ERG – Trace array

49. Multiplot

50. Case 3

51. Fullfield ERG
Retinitis Pigmentosa

52. Multifocal ERG – Trace array

53. MultiPlot

54. Case 4
JUVENILE RETINOSCHISIS

55. Case 5 Fine RPE stippling in normal looking fundus –
Chloroquine toxicity

59. MICROPERIMETRY
It is an instrument for fundus related perimetry - assess the central visual field and correlates the findings directly to the fundus location
Captures patient’s retina and simultaneously projects light stimuli on to the retina
Stimuli have been projected and the operator customizes the pattern of stimuli according to the retinal disease
Easily adapted to the different diseases of macula
Assess also the patient’s fixation site and stability of fixation over time as stable, relatively unstable and unstable
With or without pupillary dilation (if undilated pupil size min 4mm required)
Persons who have low vision or fixation problems, the stimulus can be made thicker or larger – also the fixation target may be chosen as either single cross, four crosses or circle, any color , any size

60. Comparison with HVF HVF
MICROPERIMETRY
Even a small central, paracenral scotoma can be detected, understand and assess macular disease
Fixation location is assessed
Direct corelation between threshold values and retinal sensitivity in decibels
Operator decides the stimuli location and time interval between the stimuli
Gives best results especially in cases of vitreo retinal surgeries(pre and post), before and after PDT THERAPHY, easily detects the defect is in the retina or visual pathway
HVF
Macular program available but relatively small central scotoma may be missed
Cannot be assessed
Similar but logarithmic values in apostils
Cannot be done

61. Fixation cross, at the macula
Retinal sensitivity in decibels

62. MAP REPRESENTATION
Fixation target four crosses
Filled green square better sensitivity
Filled yellow square moderate sensitivity
Filled red square poor retinal sensitivity
Empty square stimulus not seen

63. operator decides when and where to project each stimulus on the tracked retinal image and its corresponding initial intensity in manual micro perimetric exam
In a semi-automatic exam the operator shall define a polygonal area on the tracked image and the number of stimuli inside the selected area.
In an automatic exam the stimuli are proposed following a pattern chosen from among the pre-determined or customized by the operator.

64. Clinical applications of micro perimetry
ARMD/AMD(atrophic and neovascular)
EARLY AMD
DIABETIC MACULAR EDEMA
VITREO RETINAL INTERFACE DISORDER
LOW VISION PATIENT
MACULAR HOLE CYST
TOXIC MACULOPATHIES
CSR
HEREDITORY RETINAL DYSTROPIES(RP, STARGARDT’S DISEASE,BEST’S DISEASE)

65. Thank You

66. PRE POST MICROPERIMETRIC IMAGE
YET TO BE PASTED