Optical coherence tomography angiography of the macular retina in primary angle closure glaucoma

Background: To detect the macular vessel density (MVD) changes in primary angle closure glaucoma (PACG) and to investigate the correlation between MVD and other glaucomatous changes. Methods: A case-control study. Eyes of 22 PACG patients with an episode of acute primary angle closure (APAC) in one of the two eyes. Structural OCT scans were used to obtain peripapillary retinal nerve fiber layer (RNFL), macular ganglion cell complex (GCC) thickness and C/D area ration. OCT angiography (OCTA) was used to measure MVD. Results: In the control group, the dense macular blood vessels were visible on OCTA， the macular vessels were sparse in the case group, and with an enlarged fovea avascular zone. There was a reduction in MVD in the case group compared with the controls (P<0.01). No correlations between MVD, VF mean deviation (MD), C/D area ratio, GCC thickness or RNFL thickness were found in the control group. In the case group, the Pearson correlation analysis showed that MVD was significantly correlated with BCVA (r=0,65, P=0.001), GCC (r=0.50, P=0.018) and VF MD (r=-0.54, P=0.009). In the case group, the multiple stepwise regression analysis, in which MVD were considered the dependent variables, showed that BCVA and GCC were significant predictors. Conclusions: Macular microvascular network attenuated and MVD reduced significantly caused by APAC. MVD was strongly linked to BCVA and GCC.