Subthreshold micropulse yellow (577nm) laser versus intravitreal Ranibizumab in treatment of center involving diabetic macular oedema

Abstract

Purpose: To evaluate the effectiveness of subthreshold micropulse laser as compared to intravitreal injection of ranibizumab in treatment of center involving diabetic macular oedema. Methods: A total of 76 eyes of 62 patients with center involving diabetic macular oedema were divided into two groups. Group A received intravitreal injection of ranibizumab while group B received subthreshold micropulse laser with rescue intravitreal injection of ranibizumab. The change from baseline in best correscted visual acuity and central subfield thickness were compared at 3, 6, 9 and 12 months follow-up. Any adverse effects were recorded. Results: Group A (n=34 eyes) experienced a statistically significant improvement in best corrected visual acuity (from 0.32±0.16 Log MAR at baseline to 0.21±0.14 Log MAR at 12 months) (P value =0.006), with a statistically significant reduction in central subfield ghickness (from 352.06±34.34µm to 289.47±58.88 µm) (P value=0.001). Group B (n=42 eyes), also experienced a statistically significant improvement in best corrected visual acuity (from 0.34±0.22 Log MAR at baseline to 0.13±0.31 Log MAR at 12 months) (P value=0.001), with a statistically significant reduction in central subfield thickness (from 300±47.34µm to 253.12±39.60 µm at 12 months) (P value= 0.009). The mean difference in best corrected visual acuity between the group B and group A was -0.08 Log MAR with a 95% CI ranging from -0.197 to 0.037, which supports the claim of non-inferiority between the two treatment regimens. No adverse effects from subthreshold micropulse laser were recorded in both groups. Conclusion: subthreshold micropulse laser with rescue intravitreal injection of ranibizumab was non inferior to intravitreal injection of ranibizumab in treatment of center involving diabetic macular oedema as regards the mean change in best corrected visual acuity.