Wavelength optimization in femtosecond laser corneal surgery.

Purpose: To evaluate the influence of wavelength on penetration depth and quality of femtosecond laser corneal incisions in view of optimizing procedures in corneal surgery assisted by ultrashort pulse lasers.

Methods: We performed penetrating and lamellar incisions on eye bank corneas using several ultrashort pulse laser sources. Several wavelengths within the near-infrared and shortwave-infrared wavelength range were used and the pulse energy was varied.

Development of a nonlinear fiber-optic spectrometer for human lung tissue exploration.

Several major lung pathologies are characterized by early modifications of the extracellular matrix (ECM) fibrillar collagen and elastin network. We report here the development of a nonlinear fiber-optic spectrometer, compatible with an endoscopic use, primarily intended for the recording of second-harmonic generation (SHG) signal of collagen and two-photon excited fluorescence (2PEF) of both collagen and elastin. Fiber dispersion is accurately compensated by the use of a specific grism-pair stretcher, allowing laser pulse temporal width around 70 fs and excitation wavelength tunability from 790 to 900 nm.

Effect of incident light wavelength and corneal edema on light scattering and penetration: laboratory study of human corneas.

Purpose: The outcome of ultrashort pulse laser surgery of the cornea is strongly influenced by the light scattering properties of the tissue, for which little data are available. The purpose of the present study is to provide quantitative values for light scattering and its relation to the degree of edema.

Methods: An experimental optical measuring setup based on confocal geometry was used to measure the unscattered and scattered fractions of light transmitted by eye bank corneas presenting various degrees of edema.

Histologic and ultrastructural characterization of corneal femtosecond laser trephination.

Purpose: The purpose of this study was to evaluate the quality of femtosecond laser corneal trephination in eye bank eyes by histologic and ultrastructural investigation.

Methods: We performed Z-shaped, tophat-shaped, and mushroom-shaped trephinations of swelled corneas from eye bank eyes using an Intralase FS60 system. The corneoscleral discs were fixed immediately after the laser procedure without removing the buttons.