Fig. 1

Selection of OPS imaging data for analysis. ^αThere were 91 new patients with OPS imaging data for analysis. Eighteen of these patients had poor quality images that precluded analysis: six had pressure artefact, three had a recording that was too short and poorly located, three had a recording that was too short, two had a recording that was short and had pressure artefact, one had unfocussed images, one was poorly located, one had pressure artefact and was poorly located, and one was short, had pressure artefact and was poorly located. These eighteen patients were excluded from the analysis. ^βOne patient had insufficient specimen for a VEGF determination. ^γOne Bangladeshi patient had no admission specimen; the 15 Indian patients could not have plasma exported. ADMA: Asymmetric dimethylarginine; Ang-2: Angiopoietin-2; OPS: Orthogonal polarization spectral; VEGF: Vascular endothelial growth factor