RTVue 100 The Next Generation OCT
description
Transcript of RTVue 100 The Next Generation OCT
RTVue 100The Next Generation OCT
Principles of OCT Technology
• Optical Coherence Tomography (OCT) uses a principle called low coherence interferometry to derive depth information of various retinal structures
• This is performed by comparing the time difference in reflected light from the retina at various depths with a reference ‘standard’
• Differences between the reflected light and the reference standard provide structural information in the form of an ‘A’ scan
Principles of OCT Technology•An A-scan is the intensity of reflected light at various retinal depths at a single retinal location
• Combining many A-scans produces a B-scan
A-scan A-scan
+ + . . . =
B-scanA-scans
Re
tina
l De
pth
Reflectance Intensity
Fourier Domain OCT – RTVue 100
• Optical Coherence Tomography (OCT) provides cross sectional imaging of the retina
• Spectrometry and Fourier Domain methods allow high speed data capture (26,000 A scans per second)
• Broad-band light source provides high depth resolution (5 microns)
The Evolution of OCT Technology
• 65 x faster• 2 x resolution
Zeiss OCT 1 and 2, 1996
Zeiss Stratus 2002
OptoVue RTVue 2006
26,000
400
100
16 10 5
Speed(A-scansper sec)
Resolution (m)
Fourier domain OCT
Time domain OCT
Evolution of Commercial OCT
1996
2002
2006
OCT 1(Time Domain)
Stratus OCT(Time Domain)
RTVue(Fourier Domain)
Time Domain OCT
SLD
Lens
Detector
Data Acquisition
Processing
Combines light from reference with reflected
light from retina
Distance determines depth in A scan
Reference mirror moves back and forth
Scanning mirror directs SLD
beam on retina
Interferometer
Broadband Light Source
Creates A-scan 1 pixel
at a time
Final A-scan
Process repeated many times to create
B-scan
Slide courtesy of Dr. Yimin Wang, USC
Fourier Domain OCT
SLD
Spectrometer analyzes signal by
wavelength FFT
Grating splits signal by
wavelength
Broadband Light Source
Reference mirror stationary
Combines light from reference with reflected
light from retina
Interferometer
Spectral interferogram
Fourier transform converts signal to
typical A-scan
Entire A-scan created at a single timeSlide courtesy of Dr. Yimin Wang, USC
Process repeated many times to create
B-scan
Fourier Domain OCT• Simultaneous• Entire A-scan at once• 2048 pixels per A scan• 26,000 A scans per second• 1024 A-scans in 0.04 sec• Faster than eye movements
Time Domain OCT• Sequential• 1 pixel at a time• 1024 pixels per A-scan• 400 A scans per second• 512 A-scans in 1.28 sec• Slower than eye movements
512 A-scans in 1.28 sec
Motion artifact
Higher speed, higher definition and higher signal.
1024 A-scans in 0.04 sec
Small blood vessels
IS/OS
Choroidal vessels
Slide courtesy of Dr. David Huang, USC
Fourier Domain OCT
• High speed reduces eye motion artifacts present in time domain OCT
• High resolution provides precise detail, allows more structures to be seen
• Larger scanning areas allow data rich maps & accurate registration for change analysis
• 3-D scanning improves clinical utility
High Speed allows 3-D scanning
B-scans provide high resolution detail
Retinal Layers with RTVue & Histology
ILMNFLGCLIPLINLOPLONLPR IS/OSRPEChoriocapillaris and choroid
Fovea ParafoveaTemporal Nasal
Macula thickness map reveals edema
RPE Elevation map reveals drusen & CNV
RPE Elevation map reveals CNV
Change Analysis for macula
Glaucoma Analysis
• RNFL Thickness Map
• Neural retinal rim
• Cup area
• RNFL TSNIT graph at 3.45 mm circle
Measuring the ganglion cellsInner retinal layer providesGanglion cell assessment:
• Axons = nerve fiber layer• Cell Body = ganglion cell layer• Dendrites = inner plexiform layer
Images courtesy of Dr. Ou Tan, USC
Ganglion cell layer in macula analyzed for glaucoma
Inner Retina Segmentation
Provides thickness of:• RNFL layer• Ganglion cell layer• Innerplexiform layer
Normal vs Glaucoma
Normal Glaucoma
CupRim
RNFL
Inner RetinaMacula Map
Retina Examples
Normal
Rod cone dystrophy
Images courtesy of Dr. Jennifer Lim, USC
Courtesy: Michael Turano, CRAColumbia University.
Cystoid Macula Edema
Courtesy: Michael Turano, CRAColumbia University.
horizontal vertical
Diabetic Retinopathy
Images courtesy of Dr. Tano, Osaka University
Central Retinal Vein Occlusion
Images courtesy of Dr. Tano, Osaka University
horizontalhorizontal verticalvertical
AMD-Classic CNV
Images courtesy of Dr. Tano, Osaka University
Idiopathic CNV
Images courtesy of Dr. Tano, Osaka University
horizontalhorizontal verticalvertical
Macula Hole
Images courtesy of Dr. Tano, Osaka University
Courtesy: Michael Turano, CRAColumbia University.
Diabetic Macula Edema with Epiretinal Membrane
Central Serous Chorioretinopathy with PED
early phase FA
56 year old Female
Sub-retinal fluid PED
Images courtesy of Dr. Tano, Osaka University
Operculum
Courtesy: Michael Turano, CRAColumbia University.
Stage 3 Full Thickness Macular Hole
Central Serous Chorioretinopathy
Images courtesy of Dr. Tano, Osaka University
Epiretinal Membrane
Images courtesy of Dr. Tano, Osaka University
Retinitis Pigmentosa
Images courtesy of Dr. Tano, Osaka University
Courtesy: Michael Turano, CRAColumbia University.
Vitreomacular Traction Syndrome with CME
Patient MB – Neovascular AMD
Fundus Photograph FA
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient MB – Neovascular AMD
Fluid accumulation
CNVCase courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient MB – Neovascular AMDFull Retinal Thickness Map RPE Elevation Map
RPE elevation due to CNVLarge area of abnormally thick retina from intraretinal
fluid accumulation Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient WB – Neovascular AMD
Fundus Photograph FA
• 86 year old male
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient WB – Neovascular AMD
CNV
Date: 1/10/07
3-D Evaluation reveals extent of CNV
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient WB – Neovascular AMDFull Retinal Thickness Map RPE Elevation Map
RPE / choroid disruption identifies presence of CNV
Some abnormal thickening and thinning
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient WB – Neovascular AMD
1/10/07
2/23/07
B-scan comparison Full retinal Thickness RPE Elevation
Treatment• 2/7 – Lucentis• 2/14 – PDT
Thinning of retina and improvement in RPE in response to treatment
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient ED – Neovascular AMD• 84 year old male, initial exam 12/13/2006
FA shows leakage just superior to fovea
Full retinal thickness shows no thickening
RPE elevation map clearly shows area of CNV superior to fovea
FA Full retinal thickness map RPE elevation map
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient ED – Neovascular AMD
Initial Exam:12/13/2006
Follow-up Exam:3/20/2007
RPE/Choroid shows some reduction in height, but overall retinal thickness increases due to intra-retinal fluid accumulation
Treatment1/17 – Macugen3/14 - Macugen
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient ED – Neovascular AMD
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Total Retinal Thickness increases RPE elevation decreases
Patient WW – AMD• 76 year old male.
Drusen
PEDs
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Patient WW – AMD
Full Retinal Thickness Map RPE Elevation Map
Localized elevations reveal location of PED and Drusen
Full Retinal thickness map normal
Case courtesy of Dr. Nalin Mehta, Colorado Retina Center
Comparison of Stratus OCT to RTVue OCT
ComparisonRTVue Stratus• Fourier Domain OCT
• 26,000 A scans per second
• 5 µm depth resolution
• Retina Assessment• Dense Full Retinal Thickness map• RPE elevation map• 3-D macula scans
• Glaucoma Assessment• RNFL map• Inner Retinal Thickness map (Ganglion cell assessment -> axon+cell body+dendrites)• Optic disc
• RTVue is 65 times faster
• RTVue has twice the depth resolution
• Time Domain OCT
• 400 A scans per second
• 10 µm depth resolution
• Retina Assessment• Sparse retinal thickness map for retina (97% interpolated)
• Glaucoma Assessment• RNFL ring for glaucoma (TSNIT curve)
Comparison of Stratus OCT to RTVue OCTGlaucoma ComparisonRTVue Stratus
• Data Captured: 9510 A scans (pixels)• Time: 370 msec• Area covered: 4 mm diameter circle • RTVue has 97% more data
• RTVue is over 5 times faster
• Data Captured 256 A scans (pixels)• Time: 1.92 seconds• Area Covered: ring at 3.45 mm diameter
Provides •Cup Area• Rim Area• RNFL Map• TSNIT graph
Provides• TSNIT graph
• RTVue provides comprehensive glaucoma information
Plus, RTVue has exclusive Retinal Ganglion Cell layer assessment• Data Captured: 14,810 A scans (pixels)• Time: 570 msec• Area covered: 7 x 7 mm
Provides• Inner Retina Map• Ganglion cell assessment in macula
• No Comparison
• RTVue provides direct ganglion cell information
• Inner retina analysis:• RNFL• Ganglion cell body• Inner plexiform layer
RTVue can provide 3-D imaging of the optic disc and RNFL
• No Comparison
• Data Captured: 51,712 A scans (pixels)• Time: 2 seconds• Area covered: 4 x 4 mm
Provides•3 D map
• RTVue provides 3 D image of optic disc and parapapillary RNFL
Comparison of Stratus OCT to RTVue OCTRetina ComparisonRTVue Stratus
• Data Captured: 19,496 A scans (pixels)• Time: 780 msec• Area covered: 5 x 5 mm
• RTVue has 96% more data• RTVue is over 2.4 times faster
• Data Captured 768 A scans (pixels)• Time: 1.9 seconds• Area Covered: circle 6 mm diameter
Provides • Dense Retinal thickness map
Provides• Sparse Retinal thickness map• 97% interpolated between lines
• RTVue provides more data and a more detailed thickness map
RTVue has 3 D imaging of the macula• Data Captured: 51,7212 A scans (pixels)• Time: 2 seconds• Area covered: 4 x 4 mm
Provides• 3 D map of the macula
• No Comparison• RTVue provides 3-D
image of macula for a comprehensive review of B-scans over large area
Plus, RTVue has RPE elevation map for Drusen and CNV• Data Captured: 19,496 A scans (pixels)• Time: 780 msec• Area covered: 5 x 5 mm
Provides • RPE Elevation map
• RTVue RPE elevation map reveals location and extent of Drusen and CNV which is missed by retinal thickness maps
• No Comparison
RTVue Details• Scan Speed: 26,000 A scans per second• Depth Resolution: 5 microns• Transverse Resolution: 15 microns• Frame Rate: 256-4096 A-scans per frame• Scan Depth 2 mm – 2.3 mm• Scan length 2 mm – 12 mm• SLD wavelength: 840 +/- 10 nm• Focus Range: -15 D to +12 D• Retina scans: Glaucoma Scans
High res line scanHigh res cross scanMacula Map over 5 mm x 5 mm3-D macula scan
Nerve Head Map over 4 mm DiameterMacula Map over 7 mm x 7 mmRNFL 3.45 scan circle3-D Optic Disc
Scan Details: Line and CrossType # Ascans, # Bscans Scan Time Transv. Res
Line 1024 1 39 msec 5.9 µm line length: 6 mm (adj. 2-12mm)
Cross 1024 2 78 msec 5.9 µm line length: 6 mm (adj. 2-12mm)
HD Line 4096 1 156 msec 1.5 µm line length: 6 mm (adj. 2-12mm)
HD Cross 4096 2 312 msec 1.5 µm line length: 6 mm (adj. 2-12mm)
line
horizontal vert
ical
High density line
HD horizontal HD
ver
tica
l
Scan Details: 3-DType # Ascans, # Bscans Scan Time Transv. Res
3-D Macula 512 101 2 sec 7.8 µm size: 4x4 mm
3-D Disc 512 101 2 sec 7.8 µm size: 4x4 mm
Scan Details: MapsType # Ascans, # Bscans Scan Time Transv. Res
MM5 (Retina) 668 22 7.5 µm 400 12 total 780 msec 7.5 µm macula map size: 5x5 mm
NHM4 (Glaucoma) 452 12 7.5 µm587 & 775 6 total 390 msec 4.3-5.2 µm map size: 4 mm diameter circle
MM7 (Glaucoma) 467 1 15.0 µm 400 15 total 580 msec 17.5 µm macula map size: 7x7 mm