AIM: To observe conjunctival inflammatory reaction and expression of inflammatory marker ICAM-1 after long time treatment with anti-glaucoma eyedrops,and to investigate the impact on conjunctiva.METHODS: Ninety primary open-angle glaucoma patients were collected.All patients were divided into three groups in accordance with the type of treatment by using the anti-glaucoma drug: combined medication group of 30 cases,single drug treatment group of 30 cases;non-drug group of 30 cases.30 cases with simple cataract acted as blank control group.Each group was divided into 3 time phrase(0-6,7-12,13-18 months)sub-groups by anti-glaucoma drug treatment time and cataract sick time,to conduct optical microscopy observation on conjunctival epithelial histomorphology and detect ICAM-1 expression.RESULTS: Single drug treatment group in applying drugs for 13-18 months had obvious bulbar conjunctival histology changes featured by its bulbar conjunctival epithelial tissue thickening,irregular shape,macrophages,lymphocytes,fibroblasts increase and irregular subconjunctival fibrous connective tissue.Combined medication group in applying drugs for 13-18 months had obvious bulbar conjunctival histology changes featured by the bulbar conjunctival tissue with varying degrees of epithelial hyperplasia or metaplasia,uneven epithelial thickness,increased number of small blood vessels in subconjunctival tissue,and macrophages,lymphocytes,fibroblasts markedly increased,goblet cells decreased.In the 13-18 months time phrase,single drug treatment group and combined medication group,compared with the other groups in ICAM-1 positive cell number of conjunctival epithelial tissue,had statistically significant differences(P<0.01).CONCLUSION:The conjunctival tissue inflammatory response and conjunctival epithelial tissue’s inflammatory marker ICAM-1 expression increased significantly.