In Vivo Confocal Imaging Of The Eye Using Tandem Scanning Confocal Microscopy (TSCM):

AbstractOver the past decade, knowledge about the ocular surface in glaucoma has significantly increased through the use of in vivo laser scanning confocal microscopy (LSCM). This in vivo imaging method can show modifications at the cellular level induced by anti-glaucoma drugs on ocular surface structures and adnexa in the eye. High-quality images of the conjunctiva, cornea, limbus, meibomian glands, and lymphoid structures during therapy can be obtained. In addition, LSCM opened new fields of research on the patho-physiology of aqueous humor (AH) hydrodynamics in untreated, and in medically or surgically treated glaucomatous patients. In these conditions, an enhancement of the trans-scleral AH outflow contributed to clarification of the mechanism of action of different anti-glaucoma medications and surgical approaches. Finally, the use of LSCM represented a huge advance in evaluation of bleb functionality after filtration surgery, defining the hallmarks of AH filtration through the bleb-wall and distinguishing functional from nonfunctional blebs. Thus, signs seen with LSCM may anticipate clinical failure, guiding the clinician in planning the appropriate timing of the various steps in bleb management. In this review we summarize the current knowledge about in vivo LSCM of the ocular surface in glaucoma.

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In vivo confocal imaging of the eye using tandem scanning confocal microscopy (TSCM)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102365 ◽

1988 ◽

Vol 46 ◽

pp. 56-57

Author(s):

J. V. Jester ◽

H. D. Cavanagh ◽

M. A. Lemp

Keyword(s):

Confocal Imaging ◽

Optical Sectioning ◽

Scanning Confocal Microscopy ◽

Reflected Light ◽

Interesting Possibility ◽

Superficial Epithelium ◽

Confocal Scanning ◽

Time Image

New developments in optical microscopy involving confocal imaging are now becoming available which dramatically increase resolution, contrast and depth of focus by optically sectioning through structures. The transparency of the anterior ocular structures, cornea and lens, make microscopic visualization and optical sectioning of the living intact eye an interesting possibility. Of the confocal microscopes available, the Tandem Scanning Reflected Light Microscope (referred to here as the Tandem Scanning Confocal Microscope), developed by Professors Petran and Hadravsky at Charles University in Pilzen, Czechoslovakia, permits real-time image acquisition and analysis facilitating in vivo studies of ocular structures.Currently, TSCM imaging is most successful for the cornea. The corneal epithelium, stroma, and endothelium have been studied in vivo and photographed in situ. Confocal scanning images of the superficial epithelium, similar to those obtained by scanning electron microscopy, show both light and dark surface epithelial cells.

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Laser-feedback microscopy: Fundamental principles and application to high-resolution biological imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100146266 ◽

1993 ◽

Vol 51 ◽

pp. 84-85

Author(s):

Alan Bearden ◽

Terrence L. Wong ◽

Morgan W. Mitchell ◽

Leslie C. Osborne ◽

Michael P. O’Neill

Keyword(s):

Confocal Microscopy ◽

Near Field ◽

Numerical Aperture ◽

Optical Microscope ◽

Lateral Resolution ◽

Objective Lens ◽

Scanning Confocal Microscopy ◽

Gaussian Profile ◽

Phase Interference

As discovered by Abbé, a fundamental limit to the lateral resolution of a conventional optical microscope is produced by “far-field” aperture diffraction at the objective lens. This limitation can be expressed in terms of the Airy disc which relates the obtainable resolution to the wavelength of light used and the objective’s numerical aperture (NA). In scanning confocal microscopy with a laser-produced Gaussian profile illumination beam, the lateral resolution in given by 1.22λ/NA. The axial resolution in this design is improved by the use of a pinhole aperture to pass light only from the objective’s focal plane. Typical best values for lateral (x,y) and axial (z) resolution for visible wavelength scanning confocal microscopy are ~200nm and ~300nm with a NA=1.4 oil immersion objective.Although optical microscopy displays limited resolution when compared to some forms of electron and scanning-probe microscopies (STM, AFM), the convenience of sample preparation and its ease in performing in vivo studies has given rise to new methods of increased resolution (e.g., “near field” techniques, photon-tunneling, phase interference contrast).

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