Efficacy and Safety of Intravitreal Conbercept, Ranibizumab, and Triamcinolone on 23-Gauge Vitrectomy for Patients with Proliferative Diabetic Retinopathy

Abstract

Introduction: To compare the effect and safety of intravitreal conbercept (IVC), intravitreal ranibizumab (IVR), or intravitreal triamcinolone acetonide (IVTA) injection on 23-gauge (23-G) pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

Methods: Fifty patients (60 eyes) of varying degrees of PDR were randomly grouped into 3 groups (1 : 1 : 1) (n = 20 in each group). The 23-G PPV was performed with intravitreal conbercept or ranibizumab injection 3-7 days before surgery or intravitreal TA injection during surgery. The experiment was randomized controlled, with a noninferiority limit of five letters. Main outcome measures included BCVA, operation time, incidence of iatrogenic retinal breaks, endodiathermy rate, and silicone oil tamponade.

Results: At 6 months after surgery, there were no significant differences of BCVA improvements, operation time, incidence of iatrogenic retinal breaks, endodiathermy rate, silicone oil tamponade, vitreous clear-up time, and the incidence of intraoperative bleeding between the IVC and IVR groups (all P values ≥ 0.05), but they were significantly different from the IVTA group (all P values < 0.05). IOP increases did not show significant differences between the IVC and IVR groups, but both were significantly different with the IVTA group. More patients had higher postoperative IOP in the IVTA group.

Conclusions: The intravitreal injection of conbercept, ranibizumab, or TA for PDR had a significant different effect on outcomes of 23-G PPV surgery. Conbercept and ranibizumab can reduce difficulty of the operation, improve the success rate of PPV surgery, and decrease the incidence of postoperative complications.

Figure 1

Study flow chart.

Figure 2

The mean changes in BCVA from baseline in IVC, IVR, and IVTA groups over 6 m were as indicated by the ETDRS chart letters. BCVA gradually increased after treatments in all three groups. The increases of BCVA were the most at the end of the first month. At the end of 6 m, the mean BCVA was improved by 25.10 ± 3.73, 26.32 ± 4.06, and 17.16 ± 2.87 letters in IVC, IVR, and IVTA groups, respectively (all P values < 0.05).

Figure 3

Comparison of outcomes of IVC, IVR, and IVTA groups at 6 m. There were no significant differences in operation time, incidence of iatrogenic retinal breaks, endodiathermy rate, and silicone oil tamponade between IVC and IVR groups. However, each of these two groups showed significant difference with the IVTA group.

Figure 4

Secondary outcomes and adverse events of the IVC, IVR, and IVTA groups at 6 m. There were no significant differences in vitreous clear-up time and the incidence of intraoperative bleeding between IVC and IVR groups, while both of these groups were significantly different from IVTA group. More patients were at high IOP level in the IVTA group than the other two groups after surgeries. However, there were no statistically significant differences in the incidence of postoperative bleeding, PRP completion rate, and reoperation probability among 3 groups.