Retinal ischemia occurs when the blood supply to the retina is inadequate, resulting in altered metabolic function due to the lack of oxygen. In fact, ischemia has been shown to play a role in neuronal cell death in a number of retinal disorders, including glaucoma, DR, ischemic optic neuropathies. Citations are important for a journal to get impact factor. Impact factor is a measure reflecting the average number of citations to recent articles published in the journal. The impact of the journal is influenced by impact factor, the journals with high impact factor are considered more important than those with lower ones.