Effect of combined mature cataract surgery and intravitreal ranibizumab injection in eyes with pre-existing diabetic macular edema

This study aimed to compare the functional and anatomical outcomes of combined cataract surgery and intravitreal ranibizumab injection in eyes with pre-existing diabetic macular edema (DME) and preoperatively obscured fundus due to advanced cataracts. After screening 350 eyes with diabetic cataracts and preoperatively obscured fundus, 39 eyes with intraoperatively confirmed DME were included in the final analysis. Eyes were randomly assigned to either the ranibizumab group (20 eyes) or the delayed treatment group (19 eyes). Best-corrected visual acuity (BCVA), total macular volume (TMV), and central subfield thickness (CST) were evaluated at 1, 4, and 12 weeks postoperatively. Intraoperative retinal examination techniques, including 25G optical fiber, wide-angle retinal photography, and intraoperative OCT, were used to enable real-time diagnosis and intervention. At 12 weeks, the ranibizumab group showed a mean BCVA improvement of 34 letters, compared to 23 letters in the delayed group (P = 0.03). The mean change in CST was − 68 μm in the ranibizumab group and 33 μm in the delayed group (P = 0.05). Changes in TMV were similar between the two groups at 12 weeks. Intravitreal ranibizumab injection during cataract surgery significantly improved visual acuity and reduced central subfield thickness at 12 weeks postoperatively in patients with pre-existing DME and preoperatively obscured fundus. This study highlights the importance of intraoperative retinal examination and timely anti-VEGF intervention in improving visual outcomes for this challenging patient population.