Thyroid-Associated Orbitopathy (TAO) is an autoimmune disorder that affects extraocular muscles of the eye due to an accumulation of some factors e.g. Glycosaminoglycans. The aim is the identification of TAO biomarkers in tears to make easier the prediction and diagnosis and to increase the knowledge about TAO. Three independent 1D electrophoresis and isobaric Tandem Mass Tag (TMT) were analysed by Mass spectrometry, using EasyProt to obtain protein identification and quantification. Globally, combining the three experiments together, 567 tear proteins were quantified, with 221 differentially expressed between TAO and control patients. Pathways analyses revealed Glycolysis as the most representative pathway. 5 interesting dehydrogenases were found in this pathway and others. These results confirmed that tear fluid is a suitable source to research biomarkers for TAO disease. In addition, these proteins that are related and connected with the oxidative stress, could open new borderlines that could increase the general knowledge about TAO.