Background: Glaucoma is a group of diseases characterized by a specific pattern of optic nerve neuropathy and retinopathy which is permenant. There is increasing evidence of glaucoma-associated corneal endothelial changes. Decrease ECD has been reported in various types of glaucoma such as primary angle-closure glaucoma, primary open-angle glaucoma (POAG) and some types of secondary glaucoma. Objectives: The purpose of this study is to evaluate the status of corneal endothelium in different type of open angle glaucoma patients by using Specular microscope comparing with the normal ones. Patients and Methods: We included (120) subjects in this study of normal and open angle glaucoma patients. This present study was a case control study; conducted on 60 open angel glaucoma patients (22 male, 38 female) with age ranged from (28) to (60) and an average 53.56 ±7.6years, compared with 60 healthy control individuals matched in age and sex. Results: There is pоsitive relationship between ECD and glaucoma which is significant in open angle than normal pоpulation. This may be of value during оur daily clinic practice especially when dealing with refractive surgery and glaucоma suspects. Quantitative analysis of CEC morphology of glaucoma patient is necessary by specular microscopy. We should measure CCT and cоnsequently we can adjust IOP to judge the real IOP of the patient and take a good reasonable decision in the treatment of glaucoma patients. High IOP should be controlled as soon as possible to prevent optic neuropathy and corneal endothelial damage. Conclusion: Glaucoma and its management may have deleterious effects on the corneal endothelium. There is still much more to learn about how increased IOP, mechanical forces, and the aqueous environment contribute to corneal endothelial cell loss broadly observed in the milieu of glaucoma treatment. A history of glaucoma surgery poses a particularly significant risk to corneal endothelial cell health and cornea transplant graft survival.