Characterizing Flow and Structure of Diabetic Retinal Neovascularization after Intravitreal Anti-VEGF Using Optical Coherence Tomography Angiography: A Pilot Study

Figure 5

Exemplary follow-up measurements of one neovascularization (NV) with initial regression and later recurrence after cessation of anti-VEGF treatment, as described in the case presentation section, equivalent to the NV in Figure 4 and NV2 in the graphs of Figures 3(a)–3(d). (a) The optical coherence tomography angiography (OCTA) en face angio image with the outline of NV-angio. (b) The OCTA en face structural image with the outline of NV-structure. (c) The binarized OCTA en face angio image with the outline of NV-angio from (a), visualizing flow density (FD) within the angio area (en face FD-angio). While the angiographic size of the NV regresses, the relative flow density remains high. (d) The binarized OCTA en face angio image with the outline of the NV-structure from (b) (en face FD-structure). While the structural area remains relatively stable, its flow density reduces. Recurrence of the NV occurs within the preexisting structural area of the NV. Column A is at baseline, column B is after one week, and column C is one month after the first anti-VEGF injection. Column D represents 22 weeks from baseline, one month after the fourth injection and at the minimal dimensions of NV. Column E shows early recurrence 32 weeks from baseline, 20 weeks after the last injection. Column F shows subtotal recurrence 37 weeks from baseline and 25 weeks after the last anti-VEGF injection, when recurrent vitreous hemorrhage on the fellow eye had occurred, and before retreatment. After retreatment a similar regression was observed.

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