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Spectroscopic features in relation to corneal hydration during excimer laser ablation
Author(s) -
GINIS HS,
MAKRIDAKI M,
ANGLOS D,
PALLIKARIS IG
Publication year - 2010
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2010.328.x
Subject(s) - excimer , cornea , excimer laser , ablation , fluorescence , irradiation , chemistry , laser , laser ablation , spectral line , analytical chemistry (journal) , biophysics , materials science , optics , chromatography , biology , medicine , physics , astronomy , nuclear physics
Purpose To record the spectrum emitted during excimer laser‐cornea interaction at fluences intensities resulting to ablation and investigate the relation between its spectroscopic features and corneal hydration. Methods Porcine corneas from eyes obtained from a local abattoir were used for the experiments. The corneal samples were de‐epithelialized and the stroma was irradiated with an ArF excimer laser (TuiLaser Braggstar 200, ArF ; λ=193 nm) The energy fluenc used varied between 180 to 250 mJ/cm2. Emission spectra for 6 hydration levels ranging from 78 to 92% were recorded. Results The spectra recorded real‐time during the laser‐tissue interaction imply the existence of plasma and molecular fluorescence while the atomic lines of Na and Ca were detected. Differences in the shape of the recorded spectra were observed for corneas at different hydration levels. It is hypothesized that this is due to the stronger molecular fluorescence emitted when over hydrated corneas are irradiated. Molecular fluorescence detected from over hydrated corneas was matched to the fluorescence spectra of tyrosin and tryptophane, 2 amino acids found in low concentration in collagen. Conclusion Differences in the intensity of molecular fluorescence were detected in the plume emitted when irradiating corneas at different hydration levels. This finding may find an application in the real‐time estimation of corneal hydration during refractive surgery