The review is devoted to the changes in tear composition in the most widespread retinal disorders: diabetic retinopathy, age macular degeneration, retinopathy of prematurity, acute blood circulation disorders, vitreoretinal pathology and also in the experimental transplantation of induced pluripotent stem cells in the model of retinal pigment epithelium dystrophy. Despite the fact that retina and tear fluid are not in touch, there is a connection between the retinal state and tear fluid metabolism due to the common regulatory pathways. Tear composition display the local physiological changes in the eye even more than blood one. Correlation between concentration of certain metabolites in tears but not in blood and stage of the pathological process in retina was revealed. The review represents data about changes of a number of metabolites playing the key role in pathogenesis of retinal diseases — factors participating in the inflammation, angiogenesis, apoptosis, hemostasis, oxidative stress. The connection between these changes in tear composition and progress of the diseases are specially highlighted because it can be used for the early diagnostics and prediction of complications that is critical for the development of optimal therapeutic strategy. Tear fluid is recently often regarded as a body fluid used for the liquid biopsy that serves for the non-invasive investigation of pathological process. Easy and non-invasive way of tear fluid collection is one more preference of the method. Progress in the detection technology that allows using of very small samples makes it possible to introduce tear fluid analysis for biomarkers to the clinical practice.
Чеснокова et al. (Wed,) studied this question.