A Randomized Prospective Study on the Timing of Ranibizumab Administration before Vitrectomy in Patients with Severe Diabetic Retinopathy: Assessing Complications, Visual Outcomes, and Retinal Traction Development

Currently, proliferative diabetic retinopathy (PDR) and diabetic macular oedema (DMO) are recognised complications of diabetes mellitus (DM) and rank among the top five leading causes of blindness and visual impairment worldwide, including among working-age individuals. The only pathogenetically justified treatment for PDR complicated by cataract and DMO with vitreomacular traction is surgery. This approach aims to restore optical media transparency, remove fibroglial tissue (FGT), relieve traction, and eliminate retinal ischaemia zones by performing panretinal photocoagulation (PRP).

Aim: The use of anti-VEGF therapy prior to vitrectomy for diabetic retinopathy remains a topic of debate. This study aims to evaluate whether pre-treatment with anti-VEGF offers clinical benefits.

Study Design: Prospective, randomised study

Place und Duration of Study: MSTC “Microsurgery of the eye”, Yekaterinburg city, Academician Bardina street 4a. Russian Federation, between 09/2022 and 05/2024.

Methodology: All patients were randomly assigned to one of three groups: Group 1: Underwent phacoemulsification and an injection of Ranibizumab, followed by vitrectomy, PRP, and silicone oil endotamponade one month later. Group 2: Received an intravitreal injection of 0.05 ml of Ranibizumab, followed 5–7 days later by phacoemulsification combined with vitrectomy, PRP, and silicone oil endotamponade. Group 3: Underwent phacoemulsification combined with vitrectomy, PRP, and silicone oil endotamponade, without prior intravitreal injection. Silicone oil was removed three months postoperatively. Clinical follow-up was conducted at 1 day, 3 months, and 6 months after surgery. The primary outcome measures were visual acuity and central retinal thickness, while secondary outcomes included the incidence of complications.

Results: The study included 113 patients with proliferative PDR in the advanced stages as classified by the ETDRS. The preoperative visual acuity was 0.04±0.02 in Group 1, 0.03±0.71 in Group 2, and 0.06±0.27 in Group 3. Central retinal thickness (CRT) was 512±9.4 µm in Group 1, 477±11.4 µm in Group 2, and 602±17.4 µm in Group 3. At the final follow-up, best-corrected visual acuity (BCVA) improved to 0.35±0.03 in Group 1, 0.41±0.03 in Group 2, and 0.22±0.07 in Group 3 (P ≤0,05). The minimum CRT at this stage was 294±19.4 µm in Group 1, 254±14.3 µm in Group 2, and 301±12.8 µm in Group 3 (P ≥0,05!). The incidence of complications at the final follow-up was as follows: retinal haemorrhage occurred in 2% of patients in both Groups 1 and 2, and 7% in Group 3 (P ≤0,05); haemophthalmos was observed in 0% of patients in Groups 1 and 2, but 9% in Group 3 (P ≤0,05); iris rubeosis occurred in 4% of patients in Group 1, 0% in Group 2, and 6% in Group 3; and tractional retinal detachment was reported in 11% of patients in Group 1, 4% in Group 2, and 19% in Group 3(P ≤0,05). Over the entire follow-up period, the overall complication rates were 30% in Group 1, 18% in Group 2, and 70% in Group 3 (P ≤0,05). The high incidence of haemorrhagic complications in Group 3 (22%) was statistically significant (P ≤0,05).

Conclusion: Preoperative administration of Ranibizumab at different intervals prior to surgical intervention statistically significantly improved both functional and anatomical outcomes in the treatment of PDR compared to sham treatment. The best functional and anatomical outcomes were observed in the group that received anti-VEGF injection five days before vitrectomy.

Recommendations: We recommend preoperative Ranibizumab before surgery. Both timings, 5 days and 30 days, give good results. In addition, we advise against vitrectomy without preoperative Ranibizumab.