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

Area of Science:

• Ophthalmology
• Medical Imaging
• Neuroscience

Background:

• Glaucoma diagnosis and monitoring can be improved by quantitatively analyzing macular capillary plexuses using optical coherence tomography angiography (OCTA).
• Identifying vascular patterns associated with localized and global visual field loss is crucial for clinical decision-making and understanding glaucoma mechanisms.

Purpose of the Study:

• To investigate the relationship between macular vessel density (measured by OCTA) and visual field loss (quantified by pattern standard deviation and mean deviation).
• To determine if perfusion metrics from the superficial and deep capillary plexuses correlate with functional deficits using OCTA and visual field analysis.

Main Methods:

• A cross-sectional study included 114 participants (38 glaucoma, 38 glaucoma suspects, 38 healthy controls).
• Macular vessel density was measured using 6x6 mm OCTA scans.
• Functional loss was assessed using Humphrey visual field parameters (pattern standard deviation, mean deviation, visual field index), and linear regression analyzed associations with vascular metrics, visual field indices, and structural measures.

Main Results:

• Deep capillary plexus vessel density strongly correlated with global functional loss (mean deviation, R²=0.88) and focal loss (pattern standard deviation, R²=0.83).
• Superficial capillary plexus vessel density significantly correlated with focal loss (pattern standard deviation, R²=0.51).
• Glaucoma eyes exhibited higher pattern standard deviation and reduced macular perfusion in both plexuses compared to suspects and controls.

Conclusions:

• 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 significant correlation with focal loss.
• OCTA serves as a valuable non-invasive biomarker for early glaucoma detection and monitoring.