Sparks in front of the eyes or flashes of light in front of the eyes are clinical diagnostic signs of temporal arteritis. Temporal arteritis, also known as cranial arteritis, is named after the anatomical site. It is an inflammatory disease of the large and medium arteries and can involve multiple sites of arteries, but all have temporal artery damage. It is characterized clinically by headache, fever, eye pain, generalized pain and progressive visual impairment or even blindness. The disease is closely related to rheumatic polymyalgia. 1.Pathogenesis The cause of the disease is still unclear. At present, it is believed that bacterial and viral infections are related to the disease, but no definite evidence has been found. Smoking and sun exposure can trigger or aggravate the disease. 2.Pathogenesis Autoimmune reaction is involved in the pathogenesis. The presence of immunoglobulins, which are antibodies against vessel wall components such as elastin, as well as immune complexes and complement, has been confirmed by observation of the lesioned vessel wall using immunofluorescence techniques, suggesting that the disease is caused by autoantibodies or autoantigen-antibody complexes activating the classical pathway of complement and causing a series of inflammatory reactions. There is also substantial evidence that T cell-mediated cytotoxicity plays an important role in the pathogenesis of the disease. It has been reported that lymphocytes can react to skeletal muscle and arterial antigens with the release of lymphokines, suggesting that cellular immune-mediated inflammatory responses also play an important role in the pathogenesis of the disease. In addition, it has been found that there is a significant familial tendency for the disease to develop, and enhanced expression of HLA-DR4 and HLA-138 may be susceptibility genes for the disease. Other vasculitides such as polyarteritis major, classic polyarteritis nodosa, and thrombo-occlusive vasculitis have been found to coexist with this disease, which suggests that immune mechanisms are directly related to the pathogenesis of this disease. It has been reported that the disease can also coexist with hypertension, atherosclerosis, diabetes mellitus and liver disease, which implies that humoral factors and metabolic abnormalities may be involved in the pathogenesis of the disease.