Time Domain OCTPredpharma

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1、RTVue 100 The 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 va

2、rious 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 Combinin

3、g many A-scans produces a B-scan A-scan A-scan + + . . . = B-scan A-scans Retinal Depth 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

4、 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-scans per sec) Resolution (m mm) Fourier domain OCT Time doma

5、in 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 mov

6、es 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 Gr

7、ating 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 time Slide courtesy of Dr. Y

8、imin 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 se

9、cond 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 moti

10、on 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 resolut

11、ion detail Retinal Layers with RTVue & Histology ILM NFL GCL IPL INL OPL ONL PR IS/OS RPE Choriocapillaris and choroid Fovea Parafovea Temporal Nasal Macula thickness map reveals edema RPE Elevation map reveals drusen & CNV RPE Elevation map reveals CNV Change Analysis for macula Glaucoma Analysis R

12、NFL Thickness Map Neural retinal rim Cup area RNFL TSNIT graph at 3.45 mm circle Measuring the ganglion cells Inner retinal layer provides Ganglion cell assessment: Axons = nerve fiber layer Cell Body = ganglion cell layer Dendrites = inner plexiform layer Images courtesy of Dr. Ou Tan, USC Ganglion

13、 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 Cup Rim RNFL Inner Retina Macula Map Retina Examples Normal Rod cone dystrophy Images courtesy of Dr. Jennifer Lim, USC

14、Courtesy: Michael Turano, CRA Columbia University. Cystoid Macula Edema Courtesy: Michael Turano, CRA Columbia University. horizontal vertical Diabetic Retinopathy Images courtesy of Dr. Tano, Osaka University Central Retinal Vein Occlusion Images courtesy of Dr. Tano, Osaka University horizontal ve

15、rtical AMD-Classic CNV Images courtesy of Dr. Tano, Osaka University Idiopathic CNV Images courtesy of Dr. Tano, Osaka University horizontal vertical Macula Hole Images courtesy of Dr. Tano, Osaka University Courtesy: Michael Turano, CRA Columbia University. Diabetic Macula Edema with Epiretinal Mem

16、brane 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, CRA Columbia University. Stage 3 Full Thickness Macular Hole Central Serous Chorioretinopathy Images courtesy of D

17、r. Tano, Osaka University Epiretinal Membrane Images courtesy of Dr. Tano, Osaka University Retinitis Pigmentosa Images courtesy of Dr. Tano, Osaka University Courtesy: Michael Turano, CRA Columbia University. Vitreomacular Traction Syndrome with CME Patient MB Neovascular AMD Fundus Photograph FA C

18、ase courtesy of Dr. Nalin Mehta, Colorado Retina Center Patient MB Neovascular AMD Fluid accumulation CNV Case courtesy of Dr. Nalin Mehta, Colorado Retina Center Patient MB Neovascular AMD Full Retinal Thickness Map RPE Elevation Map RPE elevation due to CNV Large area of abnormally thick retina fr

19、om 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

20、 courtesy of Dr. Nalin Mehta, Colorado Retina Center Patient WB Neovascular AMD Full 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

21、/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 sh

22、ows 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 Fol

23、low-up Exam: 3/20/2007 RPE/Choroid shows some reduction in height, but overall retinal thickness increases due to intra-retinal fluid accumulation Treatment 1/17 Macugen 3/14 - Macugen Case courtesy of Dr. Nalin Mehta, Colorado Retina Center Patient ED Neovascular AMD Case courtesy of Dr. Nalin Meht

24、a, 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

25、 Full Retinal thickness map normal Case courtesy of Dr. Nalin Mehta, Colorado Retina Center Comparison of Stratus OCT to RTVue OCT Comparison RTVue Stratus Fourier Domain OCT 26,000 A scans per second 5 m depth resolution Retina Assessment Dense Full Retinal Thickness map RPE elevation map 3-D macul

26、a 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 m depth resolution Retina Assessment Sparse retinal thickness map

27、for retina (97% interpolated) Glaucoma Assessment RNFL ring for glaucoma (TSNIT curve) Comparison of Stratus OCT to RTVue OCT Glaucoma Comparison RTVue 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

28、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

29、 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 RN

30、FL 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 OCT Retina Comparison RTVue Stratus Data Captured: 19,496 A scans (pixels) Time: 780 msec A

31、rea 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

32、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 e

33、levation 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 sca

34、ns 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 scan High res cross scan Macula Map ov

35、er 5 mm x 5 mm 3-D macula scan Nerve Head Map over 4 mm Diameter Macula Map over 7 mm x 7 mm RNFL 3.45 scan circle 3-D Optic Disc Scan Details: Line and Cross Type # Ascans, # Bscans Scan Time Transv. Res Line 1024 1 39 msec 5.9 m line length: 6 mm (adj. 2-12mm) Cross 1024 2 78 msec 5.9 m line lengt

36、h: 6 mm (adj. 2-12mm) HD Line 4096 1 156 msec 1.5 m line length: 6 mm (adj. 2-12mm) HD Cross 4096 2 312 msec 1.5 m line length: 6 mm (adj. 2-12mm) line horizontal vertical High density line HD horizontal HD vertical Scan Details: 3-D Type # Ascans, # Bscans Scan Time Transv. Res 3-D Macula 512 101 2

37、 sec 7.8 m size: 4x4 mm 3-D Disc 512 101 2 sec 7.8 m size: 4x4 mm Scan Details: Maps Type # Ascans, # Bscans Scan Time Transv. Res MM5 (Retina) 668 22 7.5 m 400 12 total 780 msec 7.5 m macula map size: 5x5 mm NHM4 (Glaucoma) 452 12 7.5 m 587 & 775 6 total 390 msec 4.3-5.2 m map size: 4 mm diameter circle MM7 (Glaucoma) 467 1 15.0 m 400 15 total 580 msec 17.5 m macula map size: 7x7 mm