A novel distribution of visual field test points to improve the correlation between structure-function measurements

Area of Science:

• Ophthalmology
• Optometry
• Medical Imaging

Background:

• Standard automated perimetry (SAP) 24-2 grids are widely used for visual field (VF) testing.
• Assessing the relationship between structural measurements (e.g., retinal nerve fiber layer thickness) and functional measurements (VF sensitivity) is crucial in glaucoma diagnosis and management.
• Existing VF grids may not optimally capture structure-function relationships in specific retinal areas.

Purpose of the Study:

• To develop a novel disc-centered field (DCF) visual field test grid.
• To identify an optimal combination of VF test points, termed the structure-function field (SFF), from DCF and standard 24-2 grids.
• To achieve the strongest sectorial correlation between retinal nerve fiber layer (RNFL) thickness and VF sensitivity.

Main Methods:

• Fifty eyes with ocular hypertension or open-angle glaucoma were studied.
• Both DCF and 24-2 visual fields were measured using Humphrey Field Analyzer II (Full Threshold strategy).
• Retinal nerve fiber layer thickness was assessed using Stratus optical coherence tomography. Test points were combined, divided into 12 sectors, and correlated with RNFL thickness to select the optimal SFF combination.

Main Results:

• The developed SFF comprises 40 test points.
• A percentile bootstrap method confirmed significantly higher sector correlation coefficients for the SFF compared to the standard 24-2 VF.
• The SFF demonstrated a stronger structure-function correlation.

Conclusions:

• The SFF offers a more robust correlation between structure and function compared to the conventional 24-2 VF, despite having fewer test locations.
• This enhanced correlation may improve the clinical interpretation of functional deficits in relation to structural damage.
• The SFF represents a potential advancement for structure-function studies in glaucoma.