Superficial and deep capillary plexus as structural surrogates for early glaucoma detection via pattern deviation.

CLINICAL RELEVANCE: Quantitative analysis of macular capillary plexuses using optical coherence tomography angiography (OCTA) may improve diagnosis and monitoring of glaucoma. Identifying vascular patterns linked to localised and global visual field loss could enhance clinical decision-making and understanding of disease mechanisms.

PURPOSE: To investigate the relationship between macular vessel density, measured by OCTA, and visual field loss quantified by pattern standard deviation and mean deviation; and to determine whether perfusion metrics from the superficial and deep capillary plexus correlate with functional deficits using OCTA and visual field analysis.

METHODS

This cross-sectional study included 114 participants: 38 with glaucoma, 38 glaucoma suspects, and 38 healthy controls. Macular vessel density of the superficial and deep capillary plexus was measured using 6 × 6 mm OCTA scans, while functional loss was assessed with Humphrey visual field parameters including pattern standard deviation, mean deviation, and the visual field index. Linear regression was performed to analyse associations between vascular metrics, visual field indices, and structural measures such as retinal nerve fibre layer and ganglion cell complex thickness.

RESULTS

Deep capillary plexus vessel density showed strong correlations with global functional loss (mean deviation, R² = 0.88, p < 0.001) and focal loss (pattern standard deviation, R² = 0.83, p < 0.001). Superficial capillary plexus vessel density was significantly associated with pattern standard deviation (R² = 0.51, p < 0.001). Glaucoma eyes showed higher pattern standard deviation (7.87 ± 3.11) than suspects (2.76 ± 1.45) and controls (2.37 ± 0.67) (p < 0.001), along with reduced macular perfusion in both plexuses.

CONCLUSION

Macular vessel density, particularly in the deep capillary plexus, is strongly associated with focal and global visual field loss in glaucoma. Superficial plexus metrics show a moderate but significant correlation with focal loss, supporting OCTA as a non-invasive biomarker for early glaucoma detection and monitoring.