Background <p>The efficacy and safety profile of the active-fluidics system (AFS) in diabetic cataract patients remains inadequately characterized. This study specifically evaluated AFS versus gravity-fluidics system (GFS) in type 2 diabetes mellitus (T2DM) patients without diabetic retinopathy (DR), evaluating early visual recovery, corneal edema patterns, and macular thickness changes.</p> Patients and methods <p>In this retrospective observational study, a total of 105 eyes of 105 T2DM patients without DR undergoing phacoemulsification at Tianjin Union Medical Center (November 2020–June 2024) were enrolled. Patients were stratified into AFS (n = 61) and GFS (n = 44) groups based on intraoperative fluidics availability. Both groups underwent standardized 2.4-mm clear corneal incision phacoemulsification using the Centurion system. Intraoperative parameters including cumulative dissipated energy (CDE), ultrasound time, total aspiration time (AT), irrigation fluid and total surgical time were recorded. Outcome measures included best-corrected visual acuity (BCVA), central corneal thickness (CCT), endothelial cell density (ECD), endothelial cell loss (ECL), and central macular thickness (CMT). Cystoid macular edema (CME) was defined as &gt; 30% CMT increase from baseline.</p> Results <p>Intraoperative parameters were comparable between groups (all P &gt; 0.05). At postoperative week 1, BCVA was statistically lower (better) in the AFS group (0.08 ± 0.11 vs. 0.13 ± 0.13 logMAR, mean difference − 0.05, 95% CI − 0.09 to 0; P = 0.046), though this 0.05 logMAR difference is below the minimal clinically important difference for cataract surgery. CCT was significantly lower in the AFS group at week 1 (577.21 ± 40.01 vs. 594.93 ± 31.40 μm, P = 0.016) and month 1 (562.64 ± 34.74 vs. 580.95 ± 40.79 μm, P = 0.014), with convergence by month 3 (P = 0.534). No intergroup differences were detected in ECD, hexagonal cell percentage, or coefficient of variation at any time point (all P &gt; 0.05). ECL percentages at month 3 showed a numerical trend toward higher loss in the AFS group (12.3% vs. 8.6%), but this did not reach statistical significance (P = 0.092; 95% CI − 0.62 to 8.08). CMT changes were comparable between groups (all P &gt; 0.7), with CME occurring in 2.9% overall.</p> Conclusion <p>In T2DM patients without DR, AFS was associated with statistically earlier but clinically modest visual recovery at week 1 and reduced early corneal edema compared with GFS. However, the modest effect sizes, borderline ECL trend, and retrospective single-center design limit definitive clinical recommendations. These findings contribute to the evidence base for fluidics selection in diabetic cataract surgery but require prospective validation before supporting practice change.</p> Clinical trial number <p>Not applicable.</p>