Correlation between Visual Acuity and Diabetic Macular Ischemia by Optical Coherence Tomography Angiography

Abstract

Diabetic macular ischemia is a not only a vision-threatening complication of diabetic retinopathy (Mansour et al. 1993), but also affects the response to treatment and the final visual outcome (Jonas et al. 2005, Chung et al. 2008). FFA is the current gold-standard in the diagnosis and management of diabetic retinopathy (ETDRS 1991a). However, besides its invasive nature, its utility in DMI is limited by its inability to view the intra-retinal vascular networks separately, and by the dynamics of dye transit (such as leakage) which may obscure or superimpose areas of ischemia and the borders of the FAZ (de Carlo et al. 2015). OCTA has the ability to rapidly and non-invasively form segmented images of the macula, allowing visualization of each vascular plexus separately. The vascular flow maps are generated by split-spectrum amplitude-decorrelation angiography (SSADA) which utilizes a motion contrast technology able to detect the flow of RBCs through the intra-retinal capillaries (Jia et al. 2012).