Abstract Background: One of the leading causes of legal blindness in adults of working age globally is diabetic retinopathy (DR). One of the main causes of central vision impairment in people with DR is diabetic macular edema (DME). Longer duration of diabetes and higher levels of haemoglobin (HbAlc) that has been glycosylated are linked to a higher risk of developing DME. Aim of Study: To examine corneal endothelial cells using specular microscopy to determine the impact of repeated intra-vitreal ranibizumab injections in diabetic patients. Patients and Methods: This interventional prospective study was conducted on 20 eyes of 20 patients with diabetic macular edema from February 2021 to November 2022 on 20 eyes of 20 recruited from the Ophthalmology department, Ain Shams university hospital and Research institute of oph-thalmology. All the study participants were investigated using specular microscopy before intravitreal ranibizumab injections and one month after three IV ranibizumab injections. Results: According to the current study, there was no signif-icant correlation between (sex, eye side, type of treatment and duration of diabetes) with endothelial cell density either before injection and after ranibizumab injection. Using logistic regres-sion, after adjustment to other variables, it was shown that age was the significant independent factor affecting endothelial cell count (cell density). Cases with higher age have lower CD. Conclusion: Intravitreal injection of ranibizumab on the corneal endothelium is a safe treatment during a short fol-low-up period.