Optical Coherence Tomography - OCT (Full)

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  • Опубликовано: 29 авг 2024
  • INTRODUCTION:
    -------------------------
    • OCT is an optical instrument that can perform cross-sectional image of biological tissue within less than 10 micron axial resolution using light waves
    • Retina is easily accessible to the external light, hence it is specially suited for retinal disorder
    • The information provided by OCT is similar to in vivo histopathology of the retina
    EXAMPLE:
     Zeiss stratus OCT
     Topcon 3D OCT-1000
    PRINCIPLE OF OCT:
    --------------------------------
    • It is a imaging technology projected light beam (820nm) near infrared light
    • The beam is then split into two beam (Probe beam & Reference beam) by Beam splitter
    • Probe beam reach to the target tissue (retina) & reference beam reach to the reference mirror
    at a known distance
    • The echo time delay of light reflected various layer of target tissue (retina) is compared with
    the echo time delay of light reflected from the reference mirror
    • A positive interference is produced when light reflected from target tissue & reference mirror
    arrives simultaneously
    • This interference is measured by a photodetector which finally produce a range of time delays
    for comparison
    • The interferometer integrates several data points over 2mm depth to construct a tomogram
    of retinal structures
    • It is real time tomogram using false color scale & different colors represent light
    backscattering from the different layers of retina
    OCT SYSTEM CONSIST OF:
    ------------------------------------------
    • Fundus viewing unit
    • Interferometer unit
    • Computer display
    • Control panel
    • Color inkjet printer
    GENERATION OF
    ----------------------------
    • OCT- 1:
    o 1st generation
    o Transverse resolution 20 micron
    o Axial resolution 10 micron
    • OCT-2:
    o 2nd generation
    o Transverse resolution 20 micron
    o Axial resolution 10 micron
    o Better user interference
    • BOTH OCT-1 & OCT-2:
    o acquire 100 vertical scan in approximately 1.2 sec
    • OCT-3:
    o 3rd generation
    o Axial resolution 7-8 micron
    o Acquire 512 vertical scan
    COLOR CODING OF OCT SCAN:
    ------------------------------------------------
    • RED-YELLOW COLORS: represents areas of maximal optical reflection & backscattering
    • BLUE & BLACK: Represents areas of minimal optical refelection & backscattering
    VARIOUS PATTERN OF B-SCAN:
    --------------------------------------------------
    • CIRCULAR SCAN FOR THE ONH RNFL:
    This generates a plot of the peripapillary RNFL thickness which is important in
    glaucoma diagnosis & monitoring
    • RADIAL LINE THROUGH ONH:
    Consist of 6-24 slices through a common central point on the ONH
    • MACULAR RADIAL LINES: Used to measure retinal thickness
    PROCEDURE OF OCT:
    """""""""""""""""""""""""""""""""""
    • STEP-1: PATIENTS DATA
     Activation of instrument & entering patients data
    • STEP-2: PATIENTS PREPARATION:
     Pupil dilate with mydriatics (tropicamide)
     Asked to look into the internal fixation target light in the
    ocular lens
    • STEP-3: PROTOCOL FOR SCAN ACQUISITION:
     Selected as per the case requirements
     The scanning beam is placed on the target area and scans
    are obtained
    • STEP-4: PRODUCTION & DISPLAY IMAGE:
     Several data points are integrated by the interferometer to
    construct a tomogram of the target area
     The tomogram is displayed in either grey scale or false color
    on a high-resolution computer screen

Комментарии • 26

  • @OphthalmologyVideos-yg6wd
    @OphthalmologyVideos-yg6wd 27 дней назад

    Anterior segment OCT ises notentiined here by the otherwise very nice presentation

  • @lyka1237
    @lyka1237 3 года назад +3

    Simple and clear explanation.

  • @mohdkhadim6420
    @mohdkhadim6420 2 года назад +1

    Thank you sir for explaining easy way

    • @optometry-with-samir
      @optometry-with-samir  2 года назад +1

      Stay with us and share with your friends.
      Thank you,
      Team Smart Optometry.

  • @priyajana3796
    @priyajana3796 3 года назад +2

    Thank you so much for explaining it in a very simple manner....

  • @abuhanif-zx3nk
    @abuhanif-zx3nk Год назад +1

    Nice presentation.

    • @optometry-with-samir
      @optometry-with-samir  Год назад

      ▪️Stay with us and share with your friends.
      ▪️Don't forget to download our App "Optometry Notes and MCQs ". It's available in Play Store.
      Thank you,
      Samir Sutradhar.

  • @dami9037
    @dami9037 2 года назад +1

    thanks for this!

    • @optometry-with-samir
      @optometry-with-samir  2 года назад

      Stay with us and share with your friends.
      Thank you,
      Team Smart Optometry.

  • @user-cs2ok5hk2m
    @user-cs2ok5hk2m 2 года назад +3

    Thank you sir for explaining easy way,and can you share the photo of the principle of the OCT

    • @optometry-with-samir
      @optometry-with-samir  2 года назад

      Page no: 491
      Google drive link: drive.google.com/file/d/1OQF0-CYHEsa2EVev2Jj1iFAeKTb5xDPG/view?usp=drivesdk
      Stay with us and share with your friends.
      Thank you,
      Team Smart Optometry.

  • @rachanasharma6616
    @rachanasharma6616 2 года назад +1

    Thank u so much ❤️

    • @optometry-with-samir
      @optometry-with-samir  2 года назад

      Stay with us and share with your friends.
      Thank you,
      Team Smart Optometry.

  • @bdprimaryschools
    @bdprimaryschools 4 года назад +1

    thank you

  • @nylanethra6294
    @nylanethra6294 2 года назад +2

    ONH is optic nerve head right?
    Not optic nerve hypoplasia

    • @optometry-with-samir
      @optometry-with-samir  2 года назад +1

      Yeah..
      It was a mistake from our side. Sorry for that...
      Thank you,
      Team Smart Optometry.

  • @arunarjun9990
    @arunarjun9990 3 года назад +3

    Please share ppt link

    • @optometry-with-samir
      @optometry-with-samir  3 года назад

      Please check the description for notes.
      Ppt is not available for this presentation.
      Thank you,
      Team Smart Optometry.

  • @user-cq5df3rr8i
    @user-cq5df3rr8i Год назад

    Dr plez i want books related to this video

  • @annienguyen2984
    @annienguyen2984 Год назад

    A part

  • @EllenRay-le4yv
    @EllenRay-le4yv 4 месяца назад

    Nures aduise drs.2418/snc