Optical properties of human sclera in spectral range 370–2500 nm (original) (raw)
Related papers
The human sclera dynamic spectra: in vitro and in vivo measurements
Ophthalmic Technologies Ix, Proceedings of, 1999
Experimental results on the optical properties of the human eye sclera controlled by administration of osmotically active chemicals, such as propylene glycol and glucose are presented. Administration of chemical agents induces diffusion of matter and as a result equalization of the refractive indices of collagen and ground material. Experimental study of influence of propylene glycol and glucose on reflectance and transmittance spectra of human eye sclera was performed. In vitro diffusion reflectance spectra of the whole human eye and transmittance spectra of the sclera samples were investigated. In vivo measurements were fulfilled on a rabbit eyes. The significant increase of transmittance and decrease of reflectance of human eye sclera and rabbit eye under action of osmolytic liquids was demonstrated. The matter diffusion coefficient for the scleral samples impregnated by glucose solution was estimated; the average value is 1 cm 5 6
Control of Optical Properties of Biotissues: I. Spectral Properties of the Eye Sclera
Optics and Spectroscopy, 2000
A method for computer modeling of transmission and diffuse reflection of a strongly scattering biotissue is described. Results of calculations of spectral characteristics for a model of the human eye sclera are presented and compared with experiments. The possibility to control optical properties of biotissues is theoretically substantiated and experimentally confirmed. Variations in color indices of biotissues are calculated using theoretical and experimental spectral characteristics obtained for the eye sclera.
Optical clearing of human eye sclera
Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 2009
We present experimental results of investigation of the optical properties of the human eye sclera controlled by administration of osmotically active chemical, such as 40%-glucose solution. Administration of the chemical agent induces diffusion of matter and as a result equalization of the refractive indices of collagen and ground material. Results of the experimental study of influence of the glucose solution on the absorption and scattering properties of human sclera are presented. In vitro reflectance and transmittance spectra of the human sclera samples were measured by commercially available spectrophotometer CARY-2415 in the spectral range from 400 to 1800 nm. The reduced scattering coefficient of human sclera samples is significantly decreased under action of the osmotical solution were demonstrated.
Measurement of Retinalamin diffusion coefficient in human sclera by optical spectroscopy
Optics and Lasers in Engineering, 2008
The use of cytomedines (such as Retinalamin) in clinical practice has shown high effectiveness of the medicaments in ophthalmology. The study of diffusion of Retinalamin in scleral tissue is important for estimation of a drug dose delivered into inner tissue of eye, time of drug action, etc. In vitro measurements of spectral reflectance of sclera interacting with aqueous solution of Retinalamin have been carried out. Ten human sclera samples were included in the study. The results of the experiments have shown that penetration of Retinalamin into scleral tissue leads to the decrease of scleral reflectance due to optical immersion. Estimation of diffusion coefficient of studied solution has been made on the basis of analysis of optical reflectance dynamics of the sclera samples. The diffusion coefficient of Retinalamin in human scleral tissue was evaluated as (1.8270.14) Â 10 À6 cm 2 /s. The results are important for treatment of partial optic atrophy observed at primary open-angle glaucoma and others eye diseases. (E.A. Genina).
Estimation of wavelength dependence of refractive index of collagen fibers of scleral tissue
Proceedings of SPIE - The International Society for Optical Engineering, 2000
We present experimental results and computer modeling on the optical properties of the human scleral tissue. The wavelength dependence of the refractive index of collagen fibers in the human scleral tissue was estimated on the base of Mie theory. Dispersion formula describing this dependence was derived. The results are general and can be used to describe optical properties of many other fibrous tissues.
Spectral Transmittance of Visible Light by the Living Human Eye
Journal of The Optical Society of America, 1965
The ocular media transmit different amounts of visible light depending on wavelength. The magnitude of this transmission can be estimated by reflecting a monochromatic beam of light off the inside of the sclera of a living eye which has an anomalous absence of choroid and retina. Measurements of this kind on three living human eyes are in good agreement with previous transmittance estimates based on in vitro spectrophotometry of enucleated eyes.
Light propagation in tissues with controlled optical properties
Journal of Biomedical Optics, 1997
Theoretical and computer modeling approaches, such as Mie theory, radiative transfer theory, diffusion wave correlation spectroscopy, and Monte Carlo simulation were used to analyze tissue optics during a process of optical clearing due to refractive index matching. Continuous wave transmittance and forward scattering measurements as well as intensity correlation experiments were used to monitor tissue structural and optical properties. As a control, tissue samples of the human sclera were taken. Osmotically active solutions, such as Trazograph, glucose, and polyethylene glycol, were used as chemicals. A characteristic time response of human scleral optical clearing the range 3 to 10 min was determined. The diffusion coefficients describing the permeability of the scleral samples to Trazograph were experimentally estimated; the average value was D T Ϸ(0.9Ϯ0.5)ϫ10 Ϫ5 cm 2 /s. The results are general and can be used to describe many other fibrous tissues.
Optical absorption and scattering of bovine cornea, lens, and retina in the near-infrared region
Lasers in Medical Science, 2011
The optical properties of bovine ocular tissues have been determined at laser wavelengths in the nearinfrared (NIR) region. The inverse adding doubling (IAD), Kubelka-Munk (KM), and inverse Monte Carlo (IMC) methods were applied to the measured values of the total diffuse transmission, total diffuse reflection, and collimated transmission to determine the optical absorption and scattering coefficients of the bovine cornea, lens and retina from 750 to 1,000 nm using a CW Ti:sapphire laser. The optical properties obtained from these three methods have been compared and are discussed.
Lasers in surgery and …, 1994
This study examines the validity of optical property measurements by comparing surface temperatures rises predicted by a well-tested mathematical model with temperatures measured experimentally during laser irradiation. Analysis is based on the early temperature response that is proportional to the absorption coefficient. The results of the investigation suggest that values for tissue absorption coefficient can be greatly overestimated when current spectrophotometric techniques are used. This seems especially true when a broad light beam and a low portto-beam-size ratio are used for transmission and reflection measurements with an integrating sphere. o