Quantitative and qualitative label free imaging using mass spectrometry in the context of an ophthalmic application

Purpose We present a new Label free quantitative imaging of small molecules in order to investigate their roles in ophthalmic disorders (toxicity, inflammation) Methods Quantitative Mass Spectrometry imaging has been developed and applied to ophthalmology to assess the distribution and quantification of Benzalkonium chloride (BAK) compound in specific areas of the eye after instillation. This method has been compared to gold standard technique as liquid chromatography - Mass spectrometry to validate the data. Results The distribution of two BAK compounds (BAK C12 and BAK C14) were investigated in small specific histological regions of the eye (such as iridocorneal angle or sclera, choroid, retina regions) in order to estimate efficiency of action or adverse effects of the treatment. High spatial resolution images were performed at cells level (30 µm). Molecular distribution was also correlated to tissue histology using H&E staining. Then, our methodology of quantification by MSI was applied. Conclusion MSI offers new insight in ocular therapeutic/pharmaceutical research, especially for high-precision distribution and quantification studies