**3.3 Optical coherence tomography angiography features of the macula in glaucoma**

The macula is an area of great interest in glaucoma since it contains the highest density of RGCs. These multilayered cells are believed to be damaged early in the disease process [34]. Not only does a correlation exist between mean macular thickness and VF sensitivity, but the macular region has also been shown to have a significantly lower VD and blood flow index in patients with glaucoma compared to healthy controls [31].

In an age-matched study, Takusagawa et al. assessed macular thickness and circulation in patients with preperimetric glaucoma (PPG) and found that they had significant macular perfusion defects compared to healthy controls [35]. The authors additionally found that within the macular region, the hemispheric superficial vascular complex (SVC) VD values were highly correlated with the corresponding GCC thickness and VF sensitivity in glaucoma patients. Their landmark findings indicate that early in the disease process, glaucoma preferentially affects perfusion in the SVC of the macula rather than the deeper plexuses.
