Abstract
Purpose: :
To investigate the Raman spectra of microbes common in keratitis by a synthetic tear model.
Methods: :
We applied the confocal Raman microspectroscopy based on the drop coating deposition (DCDR) method on Ti/Au-coated glass slide to sample spectra from synthetic tears (ST), ST mixed with microbes, including Staphylococcus aureus, Pseudomonas aeruginosa, Fusarium solani, and Acanthamoba castellanii. Raman spectra collected by a line-mapping sampling procedure in the different locations of a dried tear drop. After a series of post-spectral processing, spectra were compared by spectral morphology directly and by the results of principle component analysis.
Results: :
The characteristic features either from specific Raman shifts or the principle components for further microbial discrimination were shown. The normalized spectra are different among pure STs or STs with microbes. The tear model based on the normalized spectra by using DCDR method was discriminative for microbes common in keratitis.
Conclusions: :
The discriminative Raman spectra of microbes in model tears might provide an encouraging prospect on the differential potential of keratitis through tear Raman spectra.
Keywords: cornea: tears/tear film/dry eye • microscopy: confocal/tunneling • detection