Tear components in thyroid associated ophthalmopathy

Thyroid associated ophthalmopathy (TAO) is the most common autoimmune inflammatory orbital disease in adults.Because of its high incidence and the threat of vision, early detection and diagnosis is critical.Proteomics of tear fluid in TAO patients demonstrates that up-regulation of inflammatory proteins is associated with downregulation of protective proteins, reflecting autoimmunity and inflammation-induced dysfunction of the lacrimal gland.Lysozyme C, lactoferrin, tear protein, anti-albumin and zinc-α-2-glycoprotein 1, cysteine protease inhibitor c, α-1 antichymotrypsin and retinal dehydrogenase in tears of patients with TAO are up-regulated, suggesting that these proteins may be involved in the inflammatory process of TAO.These protein-biomarkers may be new approaches to the future research of TAO.The concentration of interleukin-7 (IL-7) in the patients with active Graves’ ophthalmopathy was significantly lower.Targeting immune restitution using IL-7 may have disease modifying effects.Exophthalmos and increasing surface area of palpebral fissure in TAO patients result in stronger evaporation and tear film lipid layer to thin.The thinner tear film lipid layer leads to faster evaporation.Meanwhile, the loss of fluid further offects the coating efficiency of tear film.So TAO patients may develop secondary evaporative dry eye.Types of protein, cytokines and prostaglandin E₂ is associated with TAO diagnosis and can be the evaluation index of TAO’s disease stage.