Bevacizumab intravitreal injections in the treatment of diabetic macular oedema

Introduction
To estimate effectiveness of bevacizumab intravitreal injections in the treatment of diabetic macular oedema.

Material and methods
The perspective study included 22 eyes in 22 patients with clinically significant diabetic macular oedema confirmed by fluorescein angiography and optical coherence tomography. Mean age of the patients was 60.6 ± 12.4 years, while mean diabetes duration was 16.0 ± 9.3 years. Vision acuity (expressed in logMAR scale), as well as anterior and posterior part of the eye were evaluated. Central retinal thickness was measured with the use of optical coherence tomography Topcon 3D OCT 1000 apparatus before and 3 weeks following each injection. Bevacizumab was administered intravitrealy in the dose of 1.25 mg/0.05 ml at monthly intervals. 10 patients were administered 3 injections, 5 patients – 2, while 7 – only 1 injection. The injection therapy was discontinued when the patients gained full vision acuity or when central retinal thickness was reduced to <250 μm. Statistical analysis of the results was performed with the use of Wilcoxon test, with significance p<0.05.

Results
Mean vision acuity prior to the therapy amounted to 0.50 (0.15–1.50) logMAR and after the first injection improved to 0.40 (0.00–1.30) logMAR (p = 0.044). Further improvement was observed after subsequent injections. As regards patients who were administered 3 injections, mean vision acuity observed after further injections improved significantly from 0.50 (0.15–1.50) logMAR prior to the treatment to: 0.45 (0.1–1.3) (p = 0.078), 0.35 (0.00–1.30) (p = 0.011), 0.25 (0.05–1.20) (p = 0.007) and 0.30 (0.10–0.70) logMAR (p = 0.018). The first injection caused no reduction of retinal thickness – 368 μm (234–708) vs. 389 (236–642) μm (p=0.602). However, following further injections decreased retinal thickness compared to the initial values; yet the differences were not significant. Retinal thickness following three injections amounted to: 407 (312–701) μm prior to the treatment, 441 (323–634) μm one month after the first injection (p = 0.959), 340 (281–679) one month after the second injection (p = 0.126), 331 (244–568) one month after the third injection (p = 0.086) and 348 (147–627) three months after the third injection (p = 0.176).

Conclusions
Intravitreal bevacizumab injections in patients with diabetic macular oedema caused a significant improvement of vision acuity and a significant reduction of central retinal thickness.