Assessment of Vascular Density, Macular Layer Thickness, and Foveal Avascular Zone in Pseudoexfoliation Disease

Abstract

Prcis: Significant reductions were observed in macular vessel density and ganglion cell layer thickness in patients with XFG and XFS; suggesting these parameters may serve as early biomarkers for diagnosing and monitoring the progression of glaucoma.

Objective: This study aims to enhance early glaucoma diagnosis in Pseudoexfoliation syndrome (XFS) patients by assessing changes in macular vessel density and retinal layer thickness, and by investigating the relationship between these parameters and disease progression from XFS to pseudoexfoliation glaucoma (XFG).

Methods: This cross-sectional study involved 25 eyes from 17 XFS patients, 32 eyes from 21 early XFG patients, and 34 age- and gender-matched healthy controls. Vessel density in the superficial and deep vascular complexes was assessed using Optical Coherence Tomography Angiography (OCTA), while the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and outer layer thickness were analyzed via spectral-domain optical coherence tomography (SD-OCT). Foveal avascular zone (FAZ) parameters were calculated, and the correlation between vessel density and macular layer thickness was examined.

Results: All groups were age- and sex-matched. Vessel density in the Superficial Vascular Complex (SVC) was significantly lower in XFG compared to controls across all sectors (P<0.05). In the Deep Vascular Complex (DVC), significant differences were seen only in the temporal sector. GCL thickness decreased significantly in all sectors, while RNFL thickness differed only in the inferior sector. Outer retinal layer thickness was significantly greater in the XFS group. FAZ area and irregularity significantly increased in the SVC across groups (P<0.05).

Conclusions: The study demonstrates that early retinal microvascular and structural changes -particularly reduced superficial vessel density in the temporal macula, thinning of the GCL, thickening of the outer retina, and FAZ enlargement -are detectable in XFS before glaucoma onset. Integrating these OCTA and SD-OCT findings into routine screening may enhance early diagnosis and guide timely intervention of glaucoma.

Keywords: exfoliation syndrome; foveal avascular zone; glaucoma; macular layer thickness; optical coherence tomography angiography; vascular density.