Abstract
Purpose: :
: To study the efficacy of the intravitreal injections of ranibizumab prior to the vitrectomy in surgical treatment of PDR.
Methods: :
Study included 80 patients with PDR and clinically significant diabetic macular edema (DME) from type I or II diabetes mellitus, aged 54-68 years. Baseline central retinal thickness (CRT) measured on Fourier-domain optical coherent tomography (OCT) (RTVue, model RT-100, Optovue, Fremont, CA) was 370-490µm. Visual acuity (VA) varied from 20/200 to 20/320. Subtotal 25-guage vitrectomy (Constellation, Alcon, USA) was performed in all patients. When required, surgery was concluded by silicon oil or air/gas or balanced salt solution (BSS) tamponade of the vitreous cavity. Patients were randomly assigned to one of the two equal groups: group I received intravitreal injection of ranibizumab 0.5mg 8-14 days prior the surgery, group II (control) was followed up without intravetreal injections. Morphological and functional outcomes of the treatments in groups I and II were analyzed and compared to the baseline data at 6-month time point after the surgery.
Results: :
At 6 months after the surgery, VA in the control group was 20/200-20/100 (p=0.21), and CRT decreased by 50±20µm (p=0.041), whereas in the ranibizumab group, VA improved to 20/50-20/30 (p <0.05), and CRT decreased by (Mean±St.D.) 110±70µm (p <0.05). Postoperative vitreous hemorrhages (in the areas of new vessels) were observed in after BSS tamponade: in the control group hemorrhages developed in 27 patients (67.5%). In four of them (10%), additional revisions of the vitreous cavity were performed to remove blood. In the rest 23 patients, hemorrhages resolved without treatment in 2-3 months. In the ranibizumab group, hemorrhages developed in 11 patients (27.5%) and resolved without treatment in 10-21 days.
Conclusions: :
Intravitreal injections of ranibizumab performed prior to vitrectomy for PDR and DME, significantly improve the efficacy of the vitrectomy, provide regression of new vessels thus decreasing the incidence of postoperative hemorrhagic complications, and improve visual and morphological outcomes.
Keywords: diabetic retinopathy • vascular endothelial growth factor • vitreoretinal surgery