Comparative Safety and Energy Efficiency of Two Phaco Power Modulation Strategies in Diabetic Patients Undergoing...

Given the reduced endothelial reserve and impaired pump function in diabetic corneas, optimizing phaco power modulation (PPM) may reduce intraoperative energy exposure and enhance corneal protection during phacoemulsification. This study aimed to compare the safety and energy efficiency of two PPM in diabetic patients undergoing phacoemulsification.

Forty eyes of 40 diabetic patients with immature cataracts and no diabetic retinopathy were enrolled, requiring optical biometry-examinable cataracts (OBEC) and adequate preoperative imaging quality. Phacoemulsification was performed using a phaco-chop technique with a Venturi-based system. Patients were assigned to PPM 1 (30% power, 30% pulse, 70% duty cycle) or PPM 2 (50% power, 70% pulse, 50% duty cycle). Absolute phaco time (APT), effective phaco time (EPT), visual acuity, and central corneal thickness (CCT) were assessed preoperatively and up to 1 month postoperatively.

PPM 1 resulted in significantly lower APT compared with PPM 2 (49.6 vs 71.1 s; p = 0.007), while EPT did not differ significantly. Both groups showed significant visual improvement, with mean visual acuity improving to LogMAR 0.08 (PPM 1) and 0.18 (PPM 2) at 1 month, without a significant intergroup difference. CCT increased transiently on postoperative day 1 (to 595.7 µm in PPM 1 and 568.4 µm in PPM 2) and returned to near-baseline values by 1 month in both groups.

Both PPM configurations were safe and effective in diabetic eyes, producing comparable visual improvement and reversible postoperative corneal thickening, supporting the use of either PPM in diabetic cataract surgery. Although PPM 1 achieved significantly lower APT, EPT and corneal recovery were similar between groups, indicating greater ultrasound efficiency without compromising corneal safety. Interpretation of these findings is limited by the small sample size, inclusion of only OBEC, and the use of CCT as an indirect surrogate of endothelial function.