Effectiveness and Safety of Vitrectomy Combined with Cataract Surgery Concurrently Versus Vitrectomy with Subsequent Cataract Surgery for Proliferative Diabetic Retinopathy Patients with Mild-moderate Cataract: A Multicenter Randomized Controlled Study

Abstract Purpose To evaluate the effectiveness and safety of pars plana vitrectomy (PPV) combined with phacoemulsification and intraocular lens implantation in proliferative diabetic retinopathy (PDR) patients over 45 years old with mild-moderate cataract, in comparison with PPV with subsequent cataract surgery. Methods This multi-center randomized controlled trial was conducted in three Chinese hospitals. From February 2021 to October 2021, 168 PDR patients were assessed for eligibility. After exclusion, a total of 129 patients were recruited and randomly assigned to PPV combined with cataract surgery concurrently (the combined group) or PPV with subsequent cataract surgery 6 months later (the subsequent group). A 12-month follow-up period was scheduled. Changes of best correct visual acuity (BCVA), rate of complications were compared between groups. Results 66 patients were assigned to the combined group and 63 to the subsequent group. The change of BCVA in the combined group with mean 36.90 (95% confidence interval, 95% CI: 30.35-43.45) letters was significantly better (adjusted difference of 16.43, 95% CI: 8.77-24.08, P<0.001) than the subsequent group with 22.40 (95% CI: 15.55-29.24) letters 6 months after the PPV, and no significant difference was found after the cataract surgery in the subsequent group. Compared with the combined group, the rates of neovascular glaucoma (17.65% vs. 3.77%, P=0.005) were significantly higher in the subsequent group. Conclusion Compared with PPV with subsequent cataract surgery, PPV combined with cataract surgery concurrently was relatively effective, convenient and safe, being a promising and reliable surgical option for PDR patients over 45 years old with mild-moderate cataract. Trial registration number NCT04729023.