Diagnostic performance of OCT and OCTA in less than 60-year-old patients with early POAG: a cross-sectional study

AIM: To observe and characterize imaging features of macular and optic disc areas in less than 60-year-old patients with early primary open angle glaucoma (POAG) by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA), and to evaluate the diagnostic value of OCT and OCTA.METHODS: Totally 15 patients (23 eyes) with early POAG as observation group and 30 health people (30 eyes) as normal control group were enrolled in this cross-sectional study. OCTA-based superficial macula vessel density, superficial macula perfusion density, superficial optic disc vessel density, superficial optic disc perfusion density and spectral domain OCT (SD-OCT)-based macular area thickness, ganglion cell complex (GCC) thickness and retinal nerve fiber layer (RNFL) thickness were measured in the two groups. Independent t-test and receiver operating characteristic curve were used for analysis. Area under the receiver operating characteristic curves (AUROC) were used to measure the diagnostic utility.RESULTS: Among all the parameters, the optimal diagnostic utility parameter was the superficial vessel density in the macular area (except the center of the macula), and the AUROC reached 0.98. The diagnostic utility of macular area perfusion density (except the center of the macula) was similar to that of superficial vessel density in the macular area, and the AUROC was above 0.97. Followed by the diagnostic utility of vessel density in the optic disc area, the best parameter was the inner ring of the vessel density, and its AUROC reached 0.97. The diagnostic utility of perfusion density in the optic disc area was slightly lower than that of vessel density in the optic disc area. The best parameter was the central optic disc perfusion density, and its AUROC was 0.95. The SD-OCT-based diagnostic utility parameters were generally lower than that mentioned above, the top three parameters were the inferior RNFL thickness (AUROC=0.919), the superior (AUROC=0.919) and the inferior GCC thickness (AUROC=0.9077).CONCLUSION: The OCT-based diagnostic utility parameters are generally lower than the OCTA-based diagnostic utility parameters. OCTA has an important clinical application value in diagnosis and evaluation for less than 60-year-old patients with early POAG.