Do Additional Testing Locations Improve the Detection of Macular Perimetric Defects in Glaucoma?

Area of Science:

• Ophthalmology
• Visual field testing
• Glaucoma diagnostics

Background:

• Glaucoma is a leading cause of irreversible blindness.
• Early detection of glaucomatous optic neuropathy (GON) is crucial for timely intervention.
• Macular visual field (VF) defects are an important indicator of disease progression.

Purpose of the Study:

• To assess if incorporating additional central testing locations enhances the detection of macular VF defects in glaucoma patients.
• To compare the diagnostic performance of a standard 24-2 grid with an expanded 24-2+ grid including 12 extra macular points.

Main Methods:

• A prospective cross-sectional study involving 440 healthy individuals and 499 patients with GON.
• Participants underwent VF testing using a fundus-tracked perimeter with both 24-2 and 24-2+ grids.
• Macular defects were defined using total deviation (TD) and pattern deviation (PD) maps at 5% and 2% normative limits, with cluster detection analysis.

Main Results:

• The 24-2+ grid, using cluster detection, identified significantly more macular defects than the 24-2 grid at matched specificity.
• Detection increases ranged from 5-10% for 5% TD/PD maps and 5-6% for 2% TD/PD maps.
• While statistically significant, the improvement in detection measured by partial areas under the receiver operating characteristic curve (pAUCs) was modest; test time increased by 21%.

Conclusions:

• Expanding visual field testing with additional macular locations offers a modest improvement in detecting macular defects in glaucomatous optic neuropathy.
• This approach can be implemented without compromising specificity when appropriate detection criteria are applied.
• The findings suggest that the 24-2+ grid is a valuable tool for enhancing glaucoma diagnosis and management.