To investigate the effect of intravitreal bevacizumab injection in preventing panretinal photocoagulation (PRP)-induced macular edema and visual dysfunction in proliferative diabetic retinopathy.

We conducted a prospective study of 40 consecutive eyes (20 patients) with proliferative diabetic retinopathy whose visual acuity (logMAR) was 0.2 or less, foveal thickness (µm) was 280 or less, and retinopathy was bilaterally symmetrical. In Group 1 (20 eyes), PRP was performed with intravitreal bevacizumab injection 1 week before the initiation of PRP, but in Group 2 (20 eyes) PRP alone was performed. In all eyes, PRP was completed using the same technique. Best corrected visual acuity (BCVA) and foveal and parafoveal thicknesses were measured before treatment and 1 and 3 months after PRP.

Before treatment, the mean BCVA and foveal and parafoveal thicknesses were not statistically significantly different between the two groups ( p >0.05). At 1 and 3 months after PRP, the mean BCVA improved and the foveal and parafoveal thicknesses were significantly smaller in Group 1 than in Group 2 ( p <0.05).

Intravitreal bevacizumab injection before PRP could help prevent PRP-induced macular edema and visual dysfunction in patients with proliferative diabetic retinopathy and good vision.