Glaucoma is an optic neuropathy characterized by irreversible loss of neural tissue over time, Advancement in OCT technology has provided an objective and quantitative method to evaluate RNFL and optic nerve head which is clearly advantageous in the effective management of patients, both in terms of diagnosis and monitoring of response to therapy. to discuss the most important glaucoma-related applications of OCT A total of 48 eyes of participants were classified into 4 groups: patient with Family history of Primary open angle glaucoma(11 eyes), patients with Ocular hyper tension (13eyes), patients with black race (12eyes) and patients with high myopia (12eyes), All study subjects will undergo complete ophthalmic examination, clinical evaluation of optic disc and Spectral domain OCT system. the mean ±SD age of the studied group was 52.2±20.2 and 66.7% of them were males while 33.3% of them were females. Glaucoma was found in 62.5% of the examined high risk group while 37.5% of them were not glaucomatous, a statistically significant difference is found only in average RNFL thickness between normal group and glaucomatous group.