Authors
Bubnova I. A.
Med.Sc.D., leading research associate1
Semchishen V. A.
Ph.D., leading research associate2
Sviridov A. P.
Ph.D., leading research associate2
Khaydukov E. V.
senior research associate2
Novikov I. A.
senior research associate1
Petrov S. Yu.
Ph.D., leading research associate1
Pakhomova N. A.
postgraduate student1
Volzhanin A. V.
resident1
1 - Scientific Research Institute of Eye Diseases, 11 A,B, Rossolimo St., Moscow, Russian Federation, 119021
2 - Institute of Photonic Technologies of Federal Research Centre «Crystallography and Photonics» of Russian Academy of Sciences, 2 Pionerskaya str., Troitsk, Moscow, Russian Federation, 142190
Abstract
Aim. To study the spectral states of polarization of the luminescence of the fibrous membranes of the eye ex vivo stimulated by linearly polarized light as a function of intraocular pressure. To study the changes in the structure of the collagen matrix of the cornea and sclera of the eye under mechanical stresses with the help of a confocal microscope and generation of a second harmonic. To evaluate the correlation of mechanical and structural changes in tissues with the polarization of luminescence.
Methods. In the experiments, rabbit eyes were used. The eyeball was fixed in a special holder, equipped with a system for setting and maintaining intraocular pressure. The photoluminescence spectra of the eyes were recorded with the help of the Jobin-Yvon Flurolog-3 spectrophotometer under excitation by linearly polarized radiation of a He-Cd laser with a wavelength of 325 nm. At the entrance to the spectrophotometer, Glan's prism was installed. A laser scanning microscope LSM-710-NLO (Carl Zeiss, Germany) was used to study the collagen matrix of the eye cornea. For the analysis of optical images, a one-dimensional wavelet analysis was used, a mathematical apparatus used to process signals of various nature and structures.
Results. Luminescence of the eye cornea, excited on the eyeball by linearly polarized radiation, is partially polarized, and the integrated intensity of the luminescence spectrum depends on the intraocular pressure. The degree of polarization of the luminescence is spectrally dependent, it can have a linear or parabolic form with a minimum near the maximum of the luminescence spectrum. The form of the spectrum of the degree of polarization depends on the position of the stimulating ray on the cornea of the eye, which may be due to parasitic luminescence of other eye tissues, such as the iris, vitreous, lens. The spectrum of the degree of polarization is sensitive to intraocular pressure. Any significant change in the structure of the collagen matrix of the cornea with intraocular pressure changes by visual examination with laser scanning microscopy could not be detected. One-dimensional wavelet analysis for the analysis of optical images makes it possible to reveal spectra of inhomogeneities in optical structures with an increase in intraocular pressure to 23, 45 and 76 mm Hg.
Conclusion. Luminescence of the eye cornea, excited on the eyeball by linearly polarized radiation, is partially polarized, and the integrated intensity of the luminescence spectrum depends on the intraocular pressure. With the help of laser scanning microscopy any significant changes in the structure of the collagen matrix of the cornea with the change in intraocular pressure could not be detected. One-dimensional wavelet analysis of optical images makes it possible to reveal spectra of inhomogeneities in optical structures with an increase in intraocular pressure to 23, 45 and 76 mm Hg.
Key words
cornea, sclera, eye fibrous tunic, luminescence, polarization, elasto-optic effect, collagen, laser scanning microscopy, wavelet analysis
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