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

•OpticalOptical involves light and optics Used for Optical biopsy of retina.

•CoherenceCoherence – two light beams of same wave length in phase. Uses principle of low coherence interferometry.

•TomographyTomography Tome/Tomo – Greek for section /cutting

4

SDOCTSDOCT

Resolution – 6 micronsResolution – 6 microns

Wavelength – 840 nmWavelength – 840 nm

3-D imaging3-D imaging

No movement artifactsNo movement artifacts

25,000 A-scans/second25,000 A-scans/second

Determining and visualizing structure that Determining and visualizing structure that absorb and scatter lightabsorb and scatter light

NoncontactNoncontact

NoninvasiveNoninvasive

5

IndicationsIndications•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

PHOTORECEPTORSPHOTORECEPTORSRPERPE

CHORIOCAPILLARISCHORIOCAPILLARIS

NFLNFL

FOVEOLAFOVEOLA

GCLGCL

ELM

ONLONL

OPLOPL

INLINLIPLIPL

8

Hyper reflectivityHyper reflectivity

Above the NFLAbove the NFL

Posterior Hyaloid ,Epiretinal Membrane,Blood

In the NFLIn the NFL

Inflammation, Cotton Wool Spots, Inflammation, Cotton Wool Spots, Blood Vessels,Blood Vessels,

Flame Shaped HemorrhagesFlame Shaped Hemorrhages

In the nuclear and plexiform layersIn the nuclear and plexiform layers

Hard Exudates, Dot Blot HemorrhagesHard Exudates, Dot Blot HemorrhagesIn the RPE CC layerIn the RPE CC layer

Hyperpigmentation, CNVHyperpigmentation, CNV

In the sub RPE layerIn the sub RPE layer

Drusens, Blood, FibrosisDrusens, Blood, FibrosisIn the choroidsIn the choroids

Scar, TransmissionScar, Transmission

Hypo reflectivityHypo reflectivity

AbsenceAbsence

EdemaEdema

Cystoid spacesCystoid spaces

Fluid – serousFluid – 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


•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


•FOVEAL CONTOUR ELEVATED AND THINNED

•HYPER REFLECTIVE INNER LAYES

•CSR

•SEROUS PED

15



•HEMORRHAGIC PED

16

•WRINLED ILM


•CYSTIC SPACES IN THE INNER RETINAL LAYERS

•SEROUS AND FIBROUS PED

17

•INCOMPLETE POSTERIOR VITREOUS DETACHMENT


•FIBROVASCULAR PED

18

•INCOMPLETE POSTERIOR VITREOUS DETACHMENT


•DRUSENOID PED

19



•HARD EXUDATES IN THE INNER RETINAL LAYERS


20



•DIFFUSE HARD EXUDATES IN THE INNER RETINAL LAYERS


21


•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


•INNER RETINAL THICKENED


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


•FOVEAL SCHISIS

•THINNED CYTIC SPACES INNER LAYERS

•RPE ALTERED

28


•OPTIC DISC PIT

29

•OPTIC DISC PIT MACULOPATHY

30

•VITREO MACULAR TRACTION

31

Case 1

• 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

PRE TREATMENT

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•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

PRE TREATMENT

S/P VIT+C3F8 UNDER GA POST TREATMENT

•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

MultiplotTrace Array

First order kernel responses- Interpretation

39

mfERG Components

• N1 – First negative trough

• P1- First positive Peak

• Origins

Cone Photoreceptors

Dominated by on and off bipolar cells

N1- IT

P1-IT

P1- AMP

N1-AMP

Parameters

40

• 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

Interpretation

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

Multiplot

Crater like defect - MfERG delineates the macular pathology

46

Case 2

Cone Dystrophy

47

Fullfield ERG

48


49

Multiplot

50

Case 3

51

Fullfield ERG

Retinitis Pigmentosa

52


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 HVFMICROPERIMETRY

• 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

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

MAP REPRESENTATION

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)

65Thank You

66

PRE POST MICROPERIMETRIC IMAGEYET TO BE PASTED

NEW INSTRUMENTS/CASE DISCUSSION

Documents

Transcript of NEW INSTRUMENTS/CASE DISCUSSION