Background: Diabetic retinopathy (DR) patients undergoing cataract surgery face potential microvascular complications, but the precise impact on macular perfusion remains unclear. This study aimed to evaluate postoperative changes in retinal microvasculature using optical coherence tomography angiography (OCTA) in DR patients without diabetic macular edema (DME) compared to non-diabetic controls.

Methods: A prospective interventional study was conducted on 108 eyes (54 DR patients and 54 controls) undergoing phacoemulsification. OCTA parameters—macular thickness (MT), superficial capillary plexus vessel density (SCP VD), perfusion density (SCP PD), and foveal avascular zone (FAZ) area—were analyzed preoperatively and 3 months postoperatively. Statistical comparisons employed paired and independent t-tests (*p* < 0.05 significant).

Results: MT increased significantly in both groups postoperatively (*p* < 0.001), with no intergroup difference in magnitude. SCP VD and SCP PD rose significantly in DR patients (*p* < 0.001) but remained unchanged in controls. FAZ area expanded in DR patients (*p* < 0.001), while controls showed no significant change.

Conclusion: Cataract surgery induces distinct microvascular remodeling in DR patients, characterized by increased SCP perfusion and FAZ enlargement, which may signal subclinical DR progression. OCTA demonstrates utility in detecting these early changes, advocating for tailored postoperative surveillance in diabetic populations to preempt vision-threatening complications.