Looking deeper into ocular surface health: an introduction to clinical tear proteomics analysis

Abstract

Ocular surface diseases are becoming more prevalent worldwide. Reasons for this include the ongoing population ageing and increasing use of digital displays, although ophthalmologists have a wide selection of tools, which can be implemented in the evaluation of the ocular surface health, methods, which enable the in-depth study of biological functions are gaining more interest. These new approaches are needed, since the individual responses to ocular surface diseases and treatments can vary from person to person, and the correlations between clinical signs and symptoms are often low. Modern mass spectrometry (MS) methods can produce information on hundreds of tear proteins, which in turn can provide valuable information on the biological effects occurring on the ocular surface. In this review article, we will provide an overview of the different aspects, which are part of a successful tear proteomics study design and equip readers with a better understanding of the methods most suited for their MSbased tear proteomics study in the field of ophthalmology and ocular surface.

Profiling Tear Film Enzymes Reveals Major Metabolic Pathways Involved in the Homeostasis of the Ocular Surface

“…The constant evolution of technologies dedicated to proteomic investigations has enabled the identi cation of thousands of proteins in numerous studies (28)(39) (40). There has been an ever-large proteomic dataset of tears due to a high number of published proteomics studies (41).…”

Clinical Tear Fluid Proteomics—A Novel Tool in Glaucoma Research

“…Over the years, different technologies including two-dimensional electrophoresis (2-DE), large-scale western blotting, and antibody microarrays have been used in proteomic analytics [ 25 ]. However, these methods come with their own limitations.…”

“…One of the main pitfalls of the MS techniques in tear proteomics is connected to the fact that the aqueous layer contains several high abundance proteins, referred to as major tear proteins, including albumin (ALB), lysozyme (LYZ), and lactotransferrin (LTF). These high-abundance proteins result in a wide dynamic range of proteins, making the detection of lower abundance proteins challenging [ 25 ].…”

Evaluation of pre-processing methods for tear fluid proteomics using the Olink platform

“…Given the close contact to the eye, and its highly abundant and concentrated proteome the changes in tear uid composition may re ect pathogenic mechanisms. [4][5][6] . At present there is an increasing interest in the use of tear uid samples to investigate various ocular and systemic diseases.…”

“…Tear uid can be collected using various methods, of which Schirmer strips and capillaries are the most common ones. 4 Tear uid collection by Schirmer strip is easy to perform, well-accepted by patients, and yields the highest protein content. 5,15,16 As a consequence, the majority of studies investigating tear proteins use these strips.…”