Optic nerve head vessel density in patients with pseudoexfoliation syndrome/glaucoma: A systematic review and meta-analysis

Purpose: Exfoliative material has been shown to accumulate in ocular and systemic tissues. We aimed to perform a systematic review and meta-analysis of the current literature evaluating optic nerve head vessel density (VD) using optical coherence tomography angiography (OCTA) in patients with XFS and XFG.Methods: Studies were retrieved from PubMed, Scopus, and Web of Science databases. Studies comparing patients with XFS and/or XFG patients to healthy controls, using the optic nerve head-centred 4.5 x 4.5 mm square OCTA scan protocol were included. Pooled results are presented as standardised mean differences with 95% confidence intervals (CI). Meta-regression analysis was performed between mean difference in circumpapillary VD between XFG and controls and mean pRNFL thickness in patients with XFG.Results: Fifteen studies with 1475 eyes were included in this review. Whole image VD and circumpapillary VD (cpVD) were significantly decreased in patients with XFS [-0.78(95% Cl:-1.08,-0.47);-0.55(95% Cl:-0.80, -0.30); respectively] and XFG [-1.85(95% CI:-2.33,-1.36);-1.84 (95% CI:-2.30,-1.39); respectively] compared to healthy controls. Furthermore, pRNFL thickness decreased in patients with XFS [-0.55(95% Cl: -0.72,-0.35)] and XFG [-1.78(95% Cl:-2.21,-1.36)] compared to healthy controls. Meta-regression showed that pRNFL thickness decreased with increasing mean cpVD difference in XFG patients compared to healthy controls.Conclusions: OCTA provides non-invasive, objective and reproducible assessment of peripapillary VD and is important for the detection of vasculopathy in patients with XFS or XFG. This study provides strong evidence for decreased cpVD in the eyes of patients with XFS and XFG.