Macular vascular density changes in different stages of chronic primary angle-closure glaucoma

Abstract

Objective: This study aims to investigate differences in macular vascular density (MVD) between individuals with chronic primary angle-closure glaucoma (CPACG) and healthy controls, as well as to evaluate cross-sectional changes in MVD at various stages of CPACG.

Method: This is a retrospective study based on the epidemiological survey of eye diseases in the local community, including 47 eyes of CPACG subjects (20 eyes at the early stage and 27 eyes at the middle-to-severe stages). All subjects underwent optical coherence tomography angiography (OCTA) imaging to detect MVD, as well as macular retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness. Linear regression analysis was performed to evaluate other ophthalmic indicators related to vascular density loss.

Results: Compared to the control group, the MVD in CPACG eyes significantly declined by 11.5% in the superficial capillary plexus (p = 0.012) and 6.8% in the deep capillary plexus. Single correlation analysis showed that MVD in CPACG eyes was significantly correlated with axial length (r = 0.493, p = 0.036), RNFL thickness (r = 0.488, p = 0.047), and mean deviation of the visual field (r = -0.546, p = 0.010). In addition, multiple regression analysis also suggested that MVD was positively correlated with GCL/RNFL thickness and negatively correlated with the mean deviation of the visual field (p = 0.004).

Conclusion: Our study demonstrated that OCTA was a valuable tool for detecting vascular deterioration in CPACG eyes, with a stronger association between MVD and visual field damage. Further research is warranted to explore the potential of MVD as a biomarker for glaucoma progression.

Keywords: ganglion cell layer; macular retinal nerve fiber layer; macular vascular density; optical coherence tomography angiography; primary angle closure glaucoma; visual field defects.

Figure 1

OCTA could detect the thickness of different layers of the retina. In the coronal direction, the macular region was scanned in the region of 6 mm × 6 mm and 3 mm × 3 mm centered on the fovea. RNFL and GCL thickness were defined as the mean value in the entire annular area of the inner ring (3 mm × 3 mm).

Figure 2

Representative image of vascular perfusion density in the superficial capillary plexus (ILM(0)-IPL(9)) in the region of 6 mm × 6 mm and 3 mm × 3 mm centered on the fovea [(A) normal control; (B) CPACG eye]. Fovea was defined as an area with an inner diameter of 1 mm centered on the fovea centralis. Parafovea was defined as the entire annular area of the inner ring (3 mm × 3 mm), which was also divided into four blocks: temporal, superior, nasal, and inferior.