Purpose:
To investigate the difference of changes of the foveal avascular zone between patients with branch retinal vein occlusion (BRVO) or diabetic macular disease (DME) after intravitreal Bevacizumab application.
Methods:
The data of two groups were assessed. 25 patients with BRVO and 28 patients with DME were included. The area (in square millimeters) of the foveal avascular zone was manually assessed by measuring the capillary circumference in an early phase fluorescein angiogram picture (SLO, Heidelberg Retina Angiograph II). The area was measured preoperatively and after 4 to 6 weeks after injection. Primary end points of this retrospective clinical study were the change of area of the foveal avascular zone during intravitreal anti-VEGF treatment and the difference between BRVO and DME.
Results:
It was found that the area of the foveal avascular zone increased in both groups. These changes were statistically significant ( p<0,001, Wilcoxon). For the BRVO group preoperatively parameters showed a mean area of 0,29 square millimeters (median 0,28, std.dev. 0,11). After 6 weeks the mean area was assessed at 0,41 square millimeters (median 0,33, std.dev. 0,35).The patients with DME had a mean area of 0,36 square millimeters (median 0,33, std.dev. 0,13). After 6 weeks the mean area was measured at 0,43 square millimeters (median 0,42, std.dev. 0,14). The change was greater in the BRVO group (39% vs. 19%).
Conclusions:
We found a significant change in the foveal avascular zone after anti-VEGF application. The area of the FAZ increased in both groups Patients with BRVO showed a greater increase than patients with diabetic macular disease. Impairment of macular micro-perfusion and capillary network needs to be considered with the application of anti-VEGF agents during treatment of macular disease in patients with DME or BRVO.
Keywords: imaging/image analysis: clinical • diabetic retinopathy • vascular endothelial growth factor