Effect of Intravitreal Bevacizumab Injection before Panretinal Photocoagulation on the Prevention of Macular Edema Aggravation in Proliferative Diabetic Retinopathy.

Objective: To investigate the effects of intravitreal bevacizumab (IVB) injection before PRP on the prevention of macular edema (ME) in patients with PDR.

Methods: This retrospective observational study included patients diagnosed with PDR treated by PRP with (combination group) or without (PRP alone group) preoperative IVB injection (1.25 mg/0.05 mL). The primary outcome measure was the change in the central macular thickness (CMT), while the secondary outcome measure was the change in visual acuity. Measurements were made before and at one, two, and three months after treatment.

Results: In the PRP alone group, the mean baseline CMT of 277.8 μm increased to 290.4 μm at one month ( = 0.201) and 308.8 μm at two months ( = 0.002), followed by a decrease to 271.2 μm at three months ( = 0.437). In the combination group, the values at baseline and one, two, and three months after PRP were 322.9 μm, 295.4 μm ( = 0.002), 330.1 μm ( = 0.906), and 274.5 μm ( = 0.030), respectively. Visual acuity changes were comparable between the two groups at all time points.

Conclusion: IVB injection before PRP leads to decreased CMT in comparison to CMT in patients with PRP alone.