Microaneurysm density in residual oedema after anti-vascular endothelial growth factor therapy for diabetic macular oedema

Purpose To investigate the relationship between microaneurysm (MA) density and residual oedema after intravitreal injection of an anti-vascular endothelial growth factor agent for the treatment of diabetic macular oedema (DMO). Methods Patients with DMO were divided into those with residual oedema (RO) and those with no residual oedema (NRO) by the presence and absence of oedema at 1 month after intravitreal injection of either aflibercept or ranibizumab. We then compared MA density, best corrected visual acuity (BCVA), central retinal thickness (CRT) and size of the severely thickened area, as indicated by a white area (WA) on optical coherence tomography. Results We examined 48 eyes in the RO group and 25 eyes in the NRO group (n = 73). In both groups, the CRT and WA size significantly decreased and BCVA improved at 1 month and thereafter. CRT was significantly higher and BCVA was poor in the RO group at 1 and 3 months, while WA size was larger at 1, 3 and 6 months compared with the NRO group (p < 0.05). The number of injections in the RO group (3.62 +/- 1.75) was larger than the NRO group (1.89 +/- 0.97; p < 0.0001). At 1 and 6 months, the MA density in the area with persistent oedema was significantly higher than in the area with improved oedema (1 month: p = 0.0001, 6 months: p = 0.029). Conclusion High MA density and extensive swelling may be characteristic of RO following treatment for DMO with intravitreal injection of either aflibercept or ranibizumab.

Automated summary

The study found that patients with residual oedema had significantly higher central retinal thickness, poorer BCVA at 1 and 3 months, and larger white area (WA) size compared to those without residual oedema at 1, 3, and 6 months. The microaneurysm (MA) density in the area with persistent oedema was significantly higher than in the area with improved oedema at 1 and 6 months. High MA density and extensive swelling may be characteristic of residual oedema following treatment for diabetic macular oedema with intravitreal injection of either aflibercept or ranibizumab.