Pattern electroretinogram changes after intravitreal bevacizumab injection for diabetic macular edema

We aimed at investigating the efficacy of intravitreal bevacizumab injection by evaluation of pattern electroretinogram (PERG) in diabetic patients with clinically significant macular edema (CSME). Thirty-five eyes of 35 patients with diabetes were treated with 2.5 mg of intravitreal bevacizumab injection as the primary therapy for CSME. The main outcome measures included best-corrected visual acuity, fundus fluorescein angiography, and P₅₀ amplitudes of pattern electroretinogram (PERG) before and after intravitreal injection. Mean visual acuity improved significantly from a mean LogMAR value of 1.1 ± 0.2 at baseline to a maximum of 0.7 ± 0.3 after a mean follow-up time of 6.4 months. The mean baseline P₅₀ and N₉₅ amplitudes of PERG before intravitreal injection were 1.4 ± 0.7 and 2.4 ± 0.8 μV, respectively. After the treatment, the mean P₅₀ amplitude of PERG was 2.4 ± 0.9 μV at 1-month, 2.3 ± 0.8 μV at 3-month, and 2.2 ± 0.8 μV at the last visit, and the mean N₉₅ amplitude of PERG was 3.4 ± 1.05 μV at 1-month, 3.3 ± 0.9 μV at 3-month, and 3.2 ± 0.9 μV at the last visit, and the mean P₅₀ and N₉₅ amplitudes were significantly higher when compared with baseline values (for each, P < .001). Mild anterior chamber inflammation in four eyes was controlled with topical corticosteroids. Eyes with diabetic macular edema treated with intravitreal bevacizumab showed improvement in visual acuity that was accompanied by improvement in PERG amplitudes. Further randomized trials are needed to investigate the role of PERG measurements in the evaluation of the efficacy of intravitreal bevacizumab injection.