Clustering of Combined 24-2 and 10-2 Visual Field Grids and Their Relationship With Circumpapillary Retinal Nerve Fiber Layer Thickness.

PURPOSE

The purpose of this study was to cluster the test points of the combined 24-2 and 10-2 visual fields (VFs) and circumpapillary retinal nerve fiber layer thickness (cpRNFLT) sectors using explanatory factor analyses (EFAs). The correlations between the VF clusters and cpRNFLT clusters were determined, and a new function-structure relationship map was determined.

METHODS

Two hundred fifty-four eyes of 166 subjects (13 normal eyes and 241 eyes with glaucoma) were studied retrospectively. All eyes had an axial length <27 mm and had undergone 24-2 and 10-2 VF tests using the Swedish Interactive Threshold Algorithm (SITA-standard) and cpRNFLT examinations by spectral domain optical coherence tomography within a 3-month period. Explanatory factor analysis was performed to group the 116 test points of the combined 24-2/10-2 VF test grids into a smaller number of VF clusters. Another EFA was performed to cluster the 24 cpRNFLT sectors. The correlations between the VF clusters and the cpRNFLT clusters were evaluated by Pearson's correlation analysis.

RESULTS

The combined 24-2/10-2 VF test grids were grouped into seven VF clusters by EFA. Another EFA grouped the cpRNFLT sectors into 11 clusters. The correlation coefficients between the corresponding VF and cpRNFLT clusters ranged from 0.304 (P < 1 × 10-6) to 0.794 (P < 2.2 × 10-16).

CONCLUSIONS

Explanatory factor analysis revealed detailed patterns of glaucomatous VF defects and glaucomatous cpRNFL thinning. Their significant correlations indicate that they have common latent factors that might be derived from a developing pattern of glaucomatous optic neuropathy. These findings support the function-structure relationship theory in glaucoma.