Diagnostic validity of optic nerve head colorimetric assessment and optical coherence tomography angiography in patients with glaucoma

Background/Aims The aim of this study was to assess the optic nerve head (ONH) and macular vessel density with optical coherence tomography angiography (OCT-A) and the ONH haemoglobin (ONH Hb) amount with Laguna ONhE program in open-angle glaucoma (OAG) patients. Methods In this prospective observational cross-sectional study, 67 OAG patients and 41 healthy age-sex frequency matched subjects were examined with OCT-A and retinal photos. The circumpapillary (wcpVD), optic nerve head (iVD) and macular (wmVD) capillary vessel density of OCT-A and ONH colorimetric assessment to determine the ONH Hb amount using the Laguna ONhE program were evaluated. Results Significant differences between normal subjects and glaucoma patients in the wcpVD (22.18 +/- 3.42 vs 16.03 +/- 2.89%; p<0.001), iVD (18.31 +/- 5.56 vs 12.52 +/- 4.67%; p<0.001), wmVD (15.60 +/- 2.34 vs 13.34 +/- 2.32%; p<0.001) and amount of ONH Hb (71.10 +/- 1.67 vs 68.86 +/- 2.46%; p<0.001) and in the papillary cup (68.14 +/- 5.25 vs 64.77 +/- 5.08%; p=0.001) were found. The Laguna ONhE glaucoma discriminant function (GDF) index had a negative value in the OAG patients and normal values in healthy subjects (-18.76 +/- 13.31 vs 7.98 +/- 14.09; p<0.001). The area under the receiver operating characteristic (ROC) curve (AUROC) for discriminating between healthy and glaucomatous eyes was highest for wcpVD (0.93; 95% CI 0.86 to 0.97, p<0.0001), followed by GDF (0.92; 95% CI 0.86 to 0.97, p<0.0001), iVD (0.79; 95% CI 0.70 to 0.86; p<0.0001) and ONH Hb (0.78; 95% CI 0.69 to 0.85, p<0.0001). Pair wise comparisons showed that the AUROC of wcpVD (0.93) was not significantly different than GDF (0.92) (p=0.855). Conclusion Laguna ONhE program and OCT-A have similar diagnostic validity in open-angle glaucoma patients.

Automated summary

The study found significant differences in multiple indicators between patients with retinal diseases and normal subjects, with the wcpVD, iVD, wmVD, and ONH Hb showing the most prominent differences.