To determine the effect of intravitreal bevacizumab injection before panretinal photocoagulation (PRP) in clinically significant macular edema (CSME) patients.

A total of 91 eyes (70 patients) having severe nonproliferative diabetic retinopathy with CSME requiring PRP were enrolled in the present study; the medical records were retrospectively reviewed and analyzed. The eyes were divided into the regular PRP group (51 eyes) and PRP with preinjection of bevacizumab (1.25 mg) group (combination group, 40 eyes) and compared. Best corrected visual acuity (BCVA) and central macular thickness (CMT) at pretreatment and 1, 3, 6, and 12 months after PRP was evaluated.

BCVA (logarithm of the minimum angle of resolution, Snellen visual acuity in parentheses) at pretreatment and 1, 3, 6, and 12 months after PRP was 0.24 (0.575), 0.27 (0.537), 0.28 (0.525), 0.28 (0.525), and 0.30 (0.501) ( p = 0.13, 0.15, 0.56 and 0.79) in the regular PRP group and 0.32 (0.479), 0.25 (0.562), 0.26 (0.549), 0.27 (0.537), and 0.36 (0.436) ( p = 0.02, 0.04, 0.02 and 0.13) in the combination group, respectively. CMT (µm) at pretreatment and 1, 3, 6, and 12 months after PRP was 257.66, 285.16, 282.21, 289.65, and 309.85 ( p = 0.00, 0.00, 0.00 and 0.00) in the regular PRP group and 349.39, 312.17, 331.15. 353.30, and 333.55 ( p = 0.04, 0.94, 0.79 and 0.06) in the combination group, respectively.

Pretreatment of anti-vascular endothelial growth factor injection before PRP affected the decrease of macular thickness for 3 months after PRP and improved visual acuity for 6 months after PRP when compared with PRP alone in patients with CSME.