Corneal retardation time as an ocular hypertension disease indicator.

A detailed analysis of the corneal retardation timeas a highly related parameter to the intraocular pressure (IOP), and its plausible role as an indicator of ocular hypertension disease.A simple theoretical expression foris derived within the corneal viscoelastic model of Kelvin-Voigt with 3 elements. This retardation time can be easily calculated from the well-known signal and pressure amplitudes of non-contact tonometers like the Ocular Response Analyzer (ORA).

Polarization response of second-harmonic images for different collagen spatial distributions.

The response to polarization of second-harmonic generation (SHG) microscopy images of samples with different collagen distributions (quasialigned, partially organized, and nonorganized) has been analyzed. A linear decay relationship between the external arrangement and polarization sensitivity was found. SHG signal from nonorganized samples presented a large structural dispersion and a weak dependence with incident polarization.

Polarization dependence of aligned collagen tissues imaged with second harmonic generation microscopy.

A polarimetric second harmonic generation (SHG) microscope was used to analyze the dependence between polarization and SHG signal from collagen-based samples. A theoretical model was also developed to investigate the SHG intensity as a function of different polarization states for a set of quasiparallel fibers. Numerical simulations were compared to experimental SHG intensity values and a fairly good agreement was found.

Second harmonic generation signal in collagen fibers: role of polarization, numerical aperture, and wavelength.

The spatial distribution of second harmonic generation (SHG) signal from collagen fibers for incident elliptical polarized light has been modeled. The beam was assumed to focus on a horizontal fiber through a microscope objective. For elliptical polarized states located along a vertical meridian of the Poincare sphere, the SHG intensity has been optimized in terms of the incident wavelength and the numerical aperture (NA) of the objective.