Optic nerve head vessel density using OCTA in patients with primary angle closure disease: A systematic review and network meta-analysis

Elevated intraocular presure secondary to angle closure in angle closure glaucoma is considered the primary mechanism in the development of optic nerve damage. There is evidence that vascular mechanisms may play a role in the pathogenesis of primary angle closure disease (PACD). We aimed to evaluate optic nerve head vessel density in PACD. PubMed, Scopus, and Web of Science were searched. Observational investigations were included. A frequentist network meta-analysis was performed. The primary outcome was circumpapillary vessel density (cpVD), and the secondary outcome was peripapillary retinal nerve fiber layer (pRNFL) thickness. One thousand twenty four eyes from eleven studies were included in the study. There was no difference in cpVD between the primary angle closure glaucoma (PACG) and acute primary angle closure (APAC) group however, there was a significant decreasing in pRNFL thickness in the PACG group compared to APAC group. In the PACG and APAC group, cpVD and pRNFL thickness were decreased compared to primary angle closure (PAC), primary angle closure suspect (PACS), and control group. There was no difference in cpVD and pRNFL thickness between PAC, PACS and control group. This study has shown that the elevated intraocular pressure is an important factor affecting optical nerve perfusion in PACD. The decreasing in cpVD and RNFL thickness was more severe in the PACG and APAC group.