Corneal polarized photoluminescence ex vivo under internal mechanical strain

Current methods of intraocular pressure (IOP) measurement cannot always deliver reliable data. Therefore, creating a new objective tonometry method is a relevant objective.

PURPOSE: To develop a confocal optic system for cornea probing by polarized light. To explore the luminescence polarization, emitted by rabbit cornea ex vivo, induced by polarized radiation depending on IOP.

METHODS: An enucleated rabbit eye was fixated in the holder with the system of IOP setup and maintenance. The local photoluminescence of the cornea was initiated by polarized radiation of diode laser with 405-nm wavelength. Photoluminescence spectrums measurement was performed by confocal Raman microscopy. To measure the co- and cross-polarized photoluminescence components, a polarization filter was directed parallel or perpendicular to the polarization vector of excitation radiation. The photoluminescence spectrums were measured with IOP of 20, 40 and 60 mmHg.

RESULTS: The spectrums of polarization degree corresponding to IOP values of 20, 40 and 60 mmHg were obtained. IOP change in the range of 20-60 mmHg did not produce any significant change of luminescence polarization specters.

CONCLUSIONS: No reliable change of measured specters was detected during the IOP change.

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