LAESI Mass Spectrometry Imaging of Contact Lens Spoilage
Mechanisms of contact lens spoilage are of interest to many researchers in various fields of study due to the potential significance of lens discomfort to patients and providers alike. Biomolecules, including lipids and proteins, have been observed to accumulate on lenses during wear. The human eye contains tear film, which comprises three main components: aqueous (produced by the lacrimal glands), lipids (or meibum, produced by the meibomium glands), and mucins (proteins). Laser Ablation Electrospray Ionization Mass Spectrometry Imaging (LAESI-MSI) is a valuable tool in the advancement of this research, as it can be used to investigate biomolecules as well as molecules inherent to the composition of the lens in both a lateral manner and throughout the depth of the sample. Because LAESI-MSI is performed at ambient pressure, contact lenses can be analyzed in the native state without sample dehydration or any other sample manipulation that could contaminate the lens or otherwise affect the quality of analysis. Furthermore, the natural water content of the hydrogel makes it particularly well-suited for analysis by a mid-IR laser tuned to the wavelength corresponding to the maximum absorption coefficient of water, 2.94 μm.