Abstract
Purpose :
Vascular Endothelial Growth Factor (VEGF) production is trigged in response to ischemia or hypoxia in the retina, common in patients with diabetic retinopathy. Anti-VEGF injection has been shown to cause a transient decrease in perfusion in the optic nerve peripapillary region [Wen et al., J Glaucoma 2019; 28 (3)]. The purpose of this study was to evaluate the acute effect of anti-VEGF on the large blood vessels alone.
Methods :
Optic Nerve Head (ONH) Angio 4.5x4.5 mm scans were obtained with using CIRRUS™ HD-OCT 5000 with AngioPlex® OCT Angiography (ZEISS, Dublin, CA) on diabetics receiving anti-VEGF as part of clinical care. Scans were taken prior to injection, and post-injection at 1, 10 and 20 minutes. ONH perfusion and flux were calculated based on the vasculature network between internal limiting membrane and retinal nerve fiber layer. The algorithm used in the instrument automatically excludes large vessels. Vessels that created a shadow in the structural en face around the RPE layer are deemed large. Perfusion is the total area of perfused vasculature/unit area in region of interest (ROI). Flux is the total area of perfused vasculature/unit area in ROI, weighted by the flow signal intensity. Perfusion and flux were calculated at each time point including only large vessels. Percent change was calculated relative to baseline at each time interval.
Results :
Peripapillary large blood vessels in 15 eyes of 12 patients (age: 58 +/-13 years) were evaluated. 5 of 15 eyes had neovascularization of the disc (NVD). Figure 1 shows an example of the large vessels included. The mean percent change for perfusion at 1, 10, 20 minutes was 1 ± 7%, 3 ± 9%, 1± 8%, and the mean percent change for flux at 1, 10, 20 minutes was 0± 6%, -2± 8%, -2± 5% (see Figure 2 A&B).
Conclusions :
Transient change in perfusion was previously demonstrated in the small capillary network following Anti-VEGF injection; however, the observed changes were not significant in the large blood vessels in this study. The fluctuations in flux and perfusion were variable, not correlating with the presence of NVD. This study suggests that transient changes in the small capillary network may be more sensitive than changes in large vessels following anti-VEGF injection.
This is a 2020 Imaging in the Eye Conference abstract.