Pericentral Scotometry Guided by Standard Perimetry Using Microperimetry in Glaucoma Patients

Area of Science:

• Ophthalmology
• Neuroscience
• Medical Imaging

Background:

• Glaucoma is a progressive optic neuropathy characterized by visual field (VF) loss and retinal ganglion cell damage.
• Accurate structure-function correlation is crucial for monitoring glaucoma progression and guiding treatment decisions.
• Standard automated perimetry (SAP) and microperimetry (MP-3) assess visual function, while optical coherence tomography (OCT) measures retinal structure, such as ganglion cell layer thickness (GCLT).

Purpose of the Study:

• To compare the strength of structure-function correlations between regionally customized high-density MP-3 microperimetry, guided by regions of interest (ROIs) from SAP, and conventional SAP in relation to GCLT in glaucoma.
• To determine if an ROI-guided approach enhances the correlation between visual field sensitivity and GCLT compared to standard methods.

Main Methods:

• A cross-sectional study involving 85 eyes of 55 glaucoma patients.
• Participants underwent SAP and MP-3 microperimetry. High-density MP-3 grids were customized to target ROIs identified as having the lowest mean sensitivity on SAP.
• Mean GCLT in the corresponding quadrant (GCLTq) was measured using OCT. Structure-function relationships were analyzed using linear mixed-effects models, comparing model performance with Akaike's Information Criterion (AIC).

Main Results:

• All visual field indices significantly correlated with GCLTq (p < 0.05).
• MP-3 mean sensitivity on a linear scale demonstrated the strongest association with GCLTq (R² = 0.139; p = 0.003), outperforming SAP.
• ROI-guided MP-3 on the linear scale showed a better model fit (ΔAIC = 8; w_i = 0.982) compared to SAP, indicating improved reliability and topographic accuracy.

Conclusions:

• Regionally customized, ROI-guided MP-3 microperimetry offers a statistically supported, albeit modest, improvement in structure-function correlation compared to conventional SAP in glaucoma.
• The ROI-targeting strategy enhances the reliability and topographic accuracy of mapping functional and structural damage in glaucoma.
• This approach provides a wider sensitivity range and stronger spatial correspondence between visual field defects and GCLT loss.