Glaucoma diagnostic capacity of optic nerve head haemoglobin measures compared with spectral domain OCT and HRT III confocal tomography

Purpose The computer program laguna onhe determines optic nerve head haemoglobin ( ONH Hb) on retinal photographs based on detecting colour differences. This study compares the diagnostic capacity of Laguna ON hE with that of spectral domain optical coherence tomography ( OCT ) and confocal tomography ( HRT III ). Methods In a prospective, observational, cross‐sectional study, glaucomatous ( n  = 66) and healthy ( n  = 52) eyes were examined by Spectralis OCT , HRT III and Laguna ON hE. The following Laguna ON hE variables were determined: ONH Hb across the vertical disc diameter (8&20 Hb), estimated cup–disc ratio (C/D) and the glaucoma discriminant function ( GDF ), which combines the slope of Hb amount with the mean in 8&20 Hb. The three diagnostic methods were compared by calculating areas under ROC curves ( AUC s). Correlations between variables were assessed through Spearman's rho coefficient. Results Areas under ROC curves (AUCs) were 0.785 (95% CI : 0.700–0.863) for GDF , 0.807 (95% CI : 0.730–0.883) for OCT retinal nerve fibre layer thickness ( OCT ‐ RNFL ) and 0.714 (95% CI : 0.618–0.810) and 0.721 (95% CI : 0.628–0.815) for the HRT III variable GPS (glaucoma probability score) and vertical C/D ratio, respectively. Glaucoma discriminant function (GDF) was correlated with OCT ‐ RNFL (0.587, p 0.001; 0.507, p 0.045; and −0.119, p 0.713 for mild, moderate and advanced glaucoma, respectively), mostly so with inferior OCT ‐ RNFL (0.622; p < 0.001). Glaucoma discriminant function (GDF)‐ HRT III correlations were lower (rim area 0.471, p < 0.0001; rim/disc area 0.426, p < 0.0001; vertical C/D −0.413, p < 0.0001; GPS −0.408, p < 0.0001; rim volume 0.341, p < 0.0001). Conclusion Similar diagnostic power was observed for Laguna ON hE, Spectralis OCT and HRT III .