Light scattering from human corneal grafts: Bulk and surface contribution

Georges, Gaëlle; Lamoine, Laure Siozade; Deumié, Carole; Conrath, J.; Hoffart, L.

doi:10.1063/1.3452334

Cited by 4 publications

(4 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is of interest in many cases, for example to eliminate or optimize light scattering from optical coatings used in, e.g., imaging systems and within the paper industry [1,2]. Restoration and conservation of art, where the bulk scattered light can be used to identify pigments [3], and studies of the transparency of the cornea for early detection of edema [4] are other examples.…”

Section: Introductionmentioning

confidence: 99%

Separation of surface and bulk reflectance by absorption of bulk scattered light

et al. 2013

View full text Add to dashboard Cite

A method is proposed for separating light reflected from turbid media with a rough surface into a bulk and a surface component. Dye is added to the sample, thereby increasing absorption and canceling bulk scattering. The remaining reflected light is surface reflectance, which can be subtracted from the total reflectance of an undyed sample to obtain the bulk component. The method is applied to paper where the addition of dye is accomplished by inkjet printing. The results show that the bulk scattered light is efficiently canceled, and that both the spectrally neutral surface reflectance and the surface topography of the undyed paper is maintained. The proposed method is particularly suitable for characterization of dielectric, highly randomized materials with significant bulk reflectance and rough surfaces, which are difficult to analyze with existing methods. A reliable separation method opens up for new ways of analyzing, e.g., biological tissues and optical coatings, and is also a valuable tool in the development of more comprehensive reflectance models.

show abstract

Section: Introductionmentioning

confidence: 99%

Separation of surface and bulk reflectance by absorption of bulk scattered light

et al. 2013

View full text Add to dashboard Cite

show abstract

“…While the curves aspect is rather similar for large angles, we notice disparities for low angles (typically inferior to 20°). As already mentioned in [ 17 ], while a major bulk scattering influence is expected for high angles, surface roughness and bulk effect may be more difficult to discriminate for lower angles. As we studied here different samples, their surfaces were likely to vary from one graft to another following the manipulations they were submitted to.…”

Section: Experimental Investigationsmentioning

confidence: 83%

“…Scattered light intensity was measured for each corneal graft (preliminary measurements were presented in [ 17 ]). This was preceded and followed by a thickness evaluation using the OCT setup, in order to take into account the dynamic of the cornea whose thickness may evolve over the duration of the entire characterization process (approximately an hour and a half for scattering measurement and OCT imaging).…”

Section: Experimental Investigationsmentioning

confidence: 99%

Light scattering from edematous human corneal grafts’ microstructure: experimental study and electromagnetic modelization

Casadessus¹,

Georges²,

Lamoine³

et al. 2012

Biomed. Opt. Express

Self Cite

View full text Add to dashboard Cite

Along with the lens, the cornea is the only transparent tissue in the human body. However, the development of an edema involves structural disturbances increasing light scattering and leading to the opacification of the cornea. Several mechanisms of transparency loss have been studied in the literature, but the whole phenomenon is complex and the part played by each scatterer is still unclear. We propose here to study human corneal grafts combining microscopic OCT imagery with far-field measurement of the scattered light in the reflected half-space. We introduce afterwards numerical calculations based on electromagnetic equations solved with first order approximation to link the observed microscopic-scale structural modifications with the intensity level of the scattered light, and to try and quantify the relationship between them.

show abstract

“…Far-field light scattering measurement has been extensively investigated over recent decades as a non-destructive and very sensitive technique to characterize surfaces and bulks. Interpreting measurements via electromagnetic theories yields the optical properties of materials: roughness spectrum, heterogeneity index, etc[32]. However, because the level of light scattering may be low compared with the specular beam, the measurements require an efficient setup with a high dynamic range.In the setup used in this study, a circle 5 mm in diameter on the sample was illuminated via a Helium Neon (HeNe) laser (632.8nm).…”

mentioning

confidence: 99%

Detection of fine modifications in bulk corneal grafts based on backscattered light quantification

Gil

Soare

Georges

et al. 2019

Optics Communications

Self Cite

View full text Add to dashboard Cite

A very sensitive technique for quantifying corneal backscattered light which measures the angleresolved light scattering throughout the reflected space is proposed. Its efficiency to detect different scattering states is compared to that of a technique currently used in hospitals: the Pentacam®. This technique, based on analyzing the backscattered light close to the specular beam, is less sensitive and it is demonstrate first on agaragar samples, for which the level of scattering is controlled. In a second time, both techniques are applied on corneal grafts and the first result is confirmed: the Pentacam® detects an edema after the corneal graft has swollen by hundreds of micrometers; the proposed technique detects the change in scattering before the cornea start to swells. Since the scattering measurements are performed in the reflected space, this highly sensitive method could be applied to in-vivo analysis.

show abstract

Light scattering from human corneal grafts: Bulk and surface contribution

Cited by 4 publications

References 29 publications

Separation of surface and bulk reflectance by absorption of bulk scattered light

Separation of surface and bulk reflectance by absorption of bulk scattered light

Light scattering from edematous human corneal grafts’ microstructure: experimental study and electromagnetic modelization

Detection of fine modifications in bulk corneal grafts based on backscattered light quantification

Contact Info

Product

Resources

About