Fig. 4: Chord diagram and co-occurrence network analysis.

Chord diagrams visualizing the quantified interrelationships between each pair of stratified clusters, and the 12 items of the J-OSDI were placed around a circle. (a) Chord diagrams showing the J-OSDI-to-cluster interrelations for J-OSDI items with a score higher than 1 (left), 2 (middle left), 3 (middle right), and 4 (right). (b) The interrelationships of the stratified clusters and the 12 items of the J-OSDI are displayed separately for each cluster. (c) Co-occurrence network analysis displaying significant connection relationships between each of the 12 J-OSDI questions within each cluster. Co-occurrence network analyses were performed with wTO measure, which enables normalization of all shared correlations between a pair of parameters. In the co-occurrence network analysis representations, nodes (the 12 items of the J-OSDI) are represented as circles, and links between the nodes (inter-item correlations) are represented as lines. The size of each node is proportional to the frequency of a DE symptom that corresponds to a J-OSDI item. The width of the lines reflects the strength of the pairwise correlations on the 12 J-OSDI domains. To enable the comparison of edge strength across networks, a thicker edge identified across all networks implied a stronger association. Purple edges represent positive interconnections, whereas green edges represent negative interconnections. Abbreviations: J-OSDI Japanese version of Ocular Surface Disease Index, wTO weighted topological overlap, DE dry eye.