The purpose of this study was to determine the effect of intracameral injection of vancomycin at the end of routine cataract surgery on macular thickness using spectral domain optical coherence tomography. This prospective comparative case series included sixty eyes of 42 patients undergoing cataract surgery. Eyes were divided into two groups: 30 eyes (Group 1) received an intracameral injection of vancomycin (1 mg/0.1 ml) at the end of surgery, and 30 eyes (Group 2) received an intracameral injection of cefuroxime (1 mg/0.1 ml). Visual acuity, average macular thickness, and retinal thickness in 9 Early Treatment Diabetic Retinopathy Study (ETDRS) sectors were measured at baseline, and 1 week, 1 month, and 3 months after surgery. There were no differences in age, gender, visual acuity, and preoperative macular thickness between groups. In Group 1, average macular thickness significantly increased 1 month after surgery compared with baseline (P = 0.000) and then stabilized. Retinal thickness significantly increased in most of the ETDRS map sectors at 1-month follow-up. In Group 2, there was a significant increase in average macular thickness 1 month after surgery compared with baseline (P = 0.037). Likewise, retinal thickness increased in most of the ETDRS subfields at 1 month. Postoperative retinal thickness values and best-corrected visual acuity were similar in both groups 1 week, 1 month, and 3 months after surgery. Intracameral injection of vancomycin at the end of cataract surgery showed comparable effects to cefuroxime in terms of macular thickness changes and visual acuity.