Background: Macular edema (ME) is a major cause of vision loss after cataract surgery in patients with diabetes. In this study we aimed to assess the macular and retinal nerve fiber layer changes after uncomplicated cataract surgery in the early postoperative period in diabetic and non-diabetic patients. Methods: This is a comparative cross-sectional study conducted on patients with cataract, included 30 patients divided into 2groups: Group 1 (Study group): Diabetes mellitus group (DM group) consists of 15 eyes with cataract (15 diabetic patients without diabetic retinopathy).  Group 2 (Control group): non diabetic group consist of 15 eyes with cataract (15 nondiabetic patients). Preoperative and 30 days postoperative OCT measurements were compared. All patients were admitted for cataract surgery (phacoemulsification) and posterior chamber intraocular lens (IOL) in Ophthalmology Department Benha University Hospital. Results and conclusion: The mean (±SD) age of diabetic group was 57.7 (±6.4). They were 6 males (40%) and 9 females (60%). While the mean (±SD) age of non-diabetic group was 60.2± (9.5). They were 9 males (60%) and 6 females (40%). Both groups were matched regarding age and gender (p>0.05 for both). Our data indicated that, although in each group; there is a significant increase in MFT and peripapillary RNFL postoperatively. However, there is a significant statistical difference between both groups regarding MFT and peripapillary RNFL after 30 days postoperative.  Also there is improvement in BCVA progressively postoperative in each group, but there is a statistical significant difference between both groups.