Confocal microscopy


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Confocal microscopy - a new method for evaluation of cornea

Published in: Health & Medicine
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Confocal microscopy

  2. 2. Introduction • 1st developed by Marvin& Minsky • Advantages over conventional light microscope • Provides high resolution images with better rejection of out of focus images • Optical sectioning ability allows image to be obtained from different depths within a thick tissue specimen • Eliminates need for processing & sectioning specimens
  3. 3. Advantages over specular microscpe • It is useful even in presence of corneal edema & scarring • It permits a 3D optical sectioning of the cornea where as specular is restricted to a single cell plane
  4. 4. Why it is called confocal • Minskys microscope had a condensor that focussed light source within a small area of the tissue with concomitant focussing of microscope objective lens on same area • Since both condensor&objective had same focal point it was called confocal
  5. 5. Types of confocal systems in clinical use • 1.Tandem scanning confocal microscope/TSCM • PRINCIPLE • Uses a modified Nipkow disc containing thousands of optically conjugate pinholes arranged in Archemedian spirals • Light from a broad light source passes through source pinholes on one side of the disc& is focussed on to the specimen
  6. 6. • Detector pinholes on opposite side of the disc prevent light from outside the optical volume determined by objective lens & pinhole diameter from reaching the eye piece • Rotation of disc allows even scanning of tissue in real time • Because illumination& detection of light through conjugate pinholes occurs in tandom this microscope is called as TSCM • ADV-it uses a broad light source which causes less tissue damage compared to laser • It provides a shallower depth of field
  7. 7. • 2.Scanning slit confocal microscope • More user friendly& commonly used • 3.Laser scanning confocal microscope • 670 nm laser beam • Highest resolution of 1-2
  8. 8. CORNEAL STRUCTURES SEEN • TSCM-Epithelial cells&subepithelial fine nerve plexus • SSCM-Epithelium,subepithelial nerve plexus& endothelium • LSCM-wing cells,langherhan cells,stromal cells&endothelium
  9. 9. Clinical application • 1.infectious keratitis • Localisation of acanthamoeba cysts & trophozoites in living eye • Detection of fungal keratitis • Filaments of fusarium,aspergillus • Bacterial contact lens induced keratitis • Microsporidial keratitis • Borrelia keratitis • To asess corneal response after refractive surgeries like PRK& LASIK