The effect of Caffeine and Hydration on Radial Peri papillary Capillary Plexus Microvascular Density in Normal and Glaucomatous Optic Nerves using Optical Coherence Tomography Angiography

Optical Coherence Tomography (OCT) is a critical tool to the modern glaucoma specialist. Change in peripapillary retinal nerve fiber layer thickness is a well-established early predictor of glaucomatous visual field progression. There is growing evidence that changes in the vasculature occur in glaucoma. OCT Angiography (OCTA) has shown that glaucomatous eyes have a reduction in vessel density in the radial peripapillary capillary plexus (RPCP) and the superficial vessel density in the macular region.4 Additionally, in eyes with progressive glaucoma damage, changes in vessel density correlate with structural changes in the retinal nerve fiber layer (RNFL) and functional changes detected by standard automated perimetry (SAP). 4 Vascular density measured by OCTA, however, is not a static measurement. It has been shown that caffeine and other vasodilatory medications can lead to a significant difference in vessel density measurements in the macula.1•2 At this point, there are no data describing the effect of caffeine or hydration status on RPCP vessel density in either glaucomatous or normal optic nerves. Ultimately, if OCT-A is to be adopted to be used clinically to monitor glaucoma for stability of the disease, an understanding of variables that influence the reproducibility of vessel density measurement is critical.