AIM: To observe the clinical effects of 23G micro-invasive vitrectomy combined with intravitreal injection of ranibizumab in the treatment of proliferative diabetic retinopathy(PDR).

METHODS: A retrospective review was performed on 78 patients with PDR who were seen between January 2016 and January 2020. Those treated with 23G micro-invasive vitrectomy alone were included in the surgery group(n=35, 41 eyes), while those treated with 23G micro-invasive vitrectomy and preoperative intravitreal injection of ranibizumab were included in the combined group(n=43, 48 eyes). The operation time, intraoperative blood loss, frequency of electric coagulation hemostasis during surgery, intraocular tamponade, occurrence of retinal tear, changes in the best corrected visual acuity(BCVA), intraocular pressure, central macular thickness(CMT)and fluorescein leakage area of retinal neovascularization before treatment, at 1d and 3mo were compared between the 2 groups. Aqueous humor samples were collected before treatment and at 1wk to determine changes in vascular endothelial growth factor(VEGF)-A, human stromal cell-derived factor-1(SDF-1)and pigment epithelial-derived factor(PEDF)levels. The incidence of surgical complications within 3mo of follow-up was counted.

RESULTS: Operation time for the combined group was shorter than that for the surgery group, the frequency of electric coagulation hemostasis, the number of eyes filled with silica-gel and the total number of intraoperative bleeding eyes were lower and smaller than those in the surgery group(P<0.05). At 1d and 3mo, the improvement of BCVA was better in the combined group than in the surgery group(P<0.05), CMT and retinal neovascularization leakage area were smaller than the surgery group(P<0.05), but no significant difference was found in intraocular pressure between the 2 groups(P>0.05). At 1wk, VEGF-A, SDF-1 and PEDF decreased in both groups(P<0.001), lower in the combined group than in the surgery group(P<0.001). The incidences of iatrogenic tear and vitreous re-hemorrhage were lower in the combined group than in the surgery group(P<0.05). There was no significant difference in the incidence of the other complications between the 2 groups(P>0.05).

CONCLUSION: 23G micro-invasive vitrectomy combined with intravitreal injection of ranibizumab is superior to 23G micro-invasive vitrectomy alone in the treatment of PDR since the combined treatment can reduce surgical difficulty, shorten the operation time, reduce intraoperative blood loss and instrument operation, promote postoperative recovery of visual acuity, inhibit retinal neovascularization, and reduce the risks of iatrogenic injury, with fewer complications. Also, it is safer and more effective.